Programs & Examples On #Procedural generation

Programmatic generation of content (graphics, sounds, level-design,...) using random or pseudo-random processes, usually on the fly.

How does one get started with procedural generation?

the most important thing is to analyze how roads, cities, blocks and buildings are structured. find out what all eg buildings have in common. look at photos, maps, plans and reality. if you do that you will be one step ahead of people who consider city building as a merely computer-technological matter.

next you should develop solutions on how to create that geometry in tiny, distinct steps. you have to define rules that make up a believable city. if you are into 3d modelling you have to rethink a lot of what you have learned so the computer can follow your instructions in any situation.

in order to not loose track you should set up a lot of operators that are only responsible for little parts of the whole process. that makes debugging, expanding and improving your system much easier. in the next step you should link those operators and check the results by changing parameters.

i have seen too many "city generators" that mainly consist of random-shaped boxes with some window textures on them : (

How to add browse file button to Windows Form using C#

var FD = new System.Windows.Forms.OpenFileDialog();
if (FD.ShowDialog() == System.Windows.Forms.DialogResult.OK) {
    string fileToOpen = FD.FileName;

    System.IO.FileInfo File = new System.IO.FileInfo(FD.FileName);

    //OR

    System.IO.StreamReader reader = new System.IO.StreamReader(fileToOpen);
    //etc
}

How to increase code font size in IntelliJ?

As of InteliJ IDEA 2017.2.5, you can change the editor font size by going to:

Settings ? Editor ? Font

enter image description here

How do I convert hex to decimal in Python?

You could use a literal eval:

>>> ast.literal_eval('0xdeadbeef')
3735928559

Or just specify the base as argument to int:

>>> int('deadbeef', 16)
3735928559

A trick that is not well known, if you specify the base 0 to int, then Python will attempt to determine the base from the string prefix:

>>> int("0xff", 0)
255
>>> int("0o644", 0)
420
>>> int("0b100", 0)
4
>>> int("100", 0)
100

Is it better practice to use String.format over string Concatenation in Java?

Here's the same test as above with the modification of calling the toString() method on the StringBuilder. The results below show that the StringBuilder approach is just a bit slower than String concatenation using the + operator.

file: StringTest.java

class StringTest {

  public static void main(String[] args) {

    String formatString = "Hi %s; Hi to you %s";

    long start = System.currentTimeMillis();
    for (int i = 0; i < 1000000; i++) {
        String s = String.format(formatString, i, +i * 2);
    }

    long end = System.currentTimeMillis();
    System.out.println("Format = " + ((end - start)) + " millisecond");

    start = System.currentTimeMillis();

    for (int i = 0; i < 1000000; i++) {
        String s = "Hi " + i + "; Hi to you " + i * 2;
    }

    end = System.currentTimeMillis();

    System.out.println("Concatenation = " + ((end - start)) + " millisecond");

    start = System.currentTimeMillis();

    for (int i = 0; i < 1000000; i++) {
        StringBuilder bldString = new StringBuilder("Hi ");
        bldString.append(i).append("Hi to you ").append(i * 2).toString();
    }

    end = System.currentTimeMillis();

    System.out.println("String Builder = " + ((end - start)) + " millisecond");

  }
}

Shell Commands : (compile and run StringTest 5 times)

> javac StringTest.java
> sh -c "for i in \$(seq 1 5); do echo \"Run \${i}\"; java StringTest; done"

Results :

Run 1
Format = 1290 millisecond
Concatenation = 115 millisecond
String Builder = 130 millisecond

Run 2
Format = 1265 millisecond
Concatenation = 114 millisecond
String Builder = 126 millisecond

Run 3
Format = 1303 millisecond
Concatenation = 114 millisecond
String Builder = 127 millisecond

Run 4
Format = 1297 millisecond
Concatenation = 114 millisecond
String Builder = 127 millisecond

Run 5
Format = 1270 millisecond
Concatenation = 114 millisecond
String Builder = 126 millisecond

How to vertically center content with variable height within a div?

This is my awesome solution for a div with a dynamic (percentaged) height.

CSS

.vertical_placer{
  background:red;
  position:absolute; 
  height:43%; 
  width:100%;
  display: table;
}

.inner_placer{  
  display: table-cell;
  vertical-align: middle;
  text-align:center;
}

.inner_placer svg{
  position:relative;
  color:#fff;
  background:blue;
  width:30%;
  min-height:20px;
  max-height:60px;
  height:20%;
}

HTML

<div class="footer">
    <div class="vertical_placer">
        <div class="inner_placer">
            <svg> some Text here</svg>
        </div>
    </div>
</div>  

Try this by yourself.

mysql said: Cannot connect: invalid settings. xampp

all you have to do is stopping

mysqld.exe

from the task manager and restart the server (Xammp)

Python way to clone a git repository

You can use dload

import dload
dload.git_clone("https://github.com/some_repo.git")

pip install dload

Capture the screen shot using .NET

It's certainly possible to grab a screenshot using the .NET Framework. The simplest way is to create a new Bitmap object and draw into that using the Graphics.CopyFromScreen method.

Sample code:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
                                            Screen.PrimaryScreen.Bounds.Height))
using (Graphics g = Graphics.FromImage(bmpScreenCapture))
{
    g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                     Screen.PrimaryScreen.Bounds.Y,
                     0, 0,
                     bmpScreenCapture.Size,
                     CopyPixelOperation.SourceCopy);
}

Caveat: This method doesn't work properly for layered windows. Hans Passant's answer here explains the more complicated method required to get those in your screen shots.

Null & empty string comparison in Bash

First of all, note you are not using the variable correctly:

if [ "pass_tc11" != "" ]; then
#     ^
#     missing $

Anyway, to check if a variable is empty or not you can use -z --> the string is empty:

if [ ! -z "$pass_tc11" ]; then
   echo "hi, I am not empty"
fi

or -n --> the length is non-zero:

if [ -n "$pass_tc11" ]; then
   echo "hi, I am not empty"
fi

From man test:

-z STRING

the length of STRING is zero

-n STRING

the length of STRING is nonzero

Samples:

$ [ ! -z "$var" ] && echo "yes"
$

$ var=""
$ [ ! -z "$var" ] && echo "yes"
$

$ var="a"
$ [ ! -z "$var" ] && echo "yes"
yes

$ var="a"
$ [ -n "$var" ] && echo "yes"
yes

Finding the second highest number in array

Scanner sc = new Scanner(System.in);

System.out.println("\n number of input sets::");
int value=sc.nextInt();
System.out.println("\n input sets::");
int[] inputset; 

inputset = new int[value];
for(int i=0;i<value;i++)
{
    inputset[i]=sc.nextInt();
}
int maxvalue=inputset[0];
int secondval=inputset[0];
for(int i=1;i<value;i++)
{
    if(inputset[i]>maxvalue)
   {
        maxvalue=inputset[i];
    }
}
for(int i=1;i<value;i++)
{
    if(inputset[i]>secondval && inputset[i]<maxvalue)
    {
        secondval=inputset[i];
    }
}
System.out.println("\n maxvalue"+ maxvalue);
System.out.println("\n secondmaxvalue"+ secondval);

Sort table rows In Bootstrap

These examples are minified because StackOverflow has a maximum character limit and links to external code are discouraged since links can break.

There are multiple plugins if you look: Bootstrap Sortable, Bootstrap Table or DataTables.

Bootstrap 3 with DataTables Example: Bootstrap Docs & DataTables Docs

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$(document).ready(function() {
  $('#example').DataTable();
});
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<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/css/dataTables.bootstrap.min.css rel=stylesheet><div class=container><h1>Bootstrap 3 DataTables</h1><table cellspacing=0 class="table table-bordered table-hover table-striped"id=example width=100%><thead><tr><th>Name<th>Position<th>Office<th>Salary<tbody><tr><td>Tiger Nixon<td>System Architect<td>Edinburgh<td>$320,800<tr><td>Garrett Winters<td>Accountant<td>Tokyo<td>$170,750<tr><td>Ashton Cox<td>Junior Technical Author<td>San Francisco<td>$86,000<tr><td>Cedric Kelly<td>Senior Javascript Developer<td>Edinburgh<td>$433,060<tr><td>Airi Satou<td>Accountant<td>Tokyo<td>$162,700<tr><td>Brielle Williamson<td>Integration Specialist<td>New York<td>$372,000<tr><td>Herrod Chandler<td>Sales Assistant<td>San Francisco<td>$137,500<tr><td>Rhona Davidson<td>Integration Specialist<td>Tokyo<td>$327,900<tr><td>Colleen Hurst<td>Javascript Developer<td>San Francisco<td>$205,500<tr><td>Sonya Frost<td>Software Engineer<td>Edinburgh<td>$103,600<tr><td>Jena Gaines<td>Office Manager<td>London<td>$90,560<tr><td>Quinn Flynn<td>Support Lead<td>Edinburgh<td>$342,000<tr><td>Charde Marshall<td>Regional Director<td>San Francisco<td>$470,600<tr><td>Haley Kennedy<td>Senior Marketing Designer<td>London<td>$313,500<tr><td>Tatyana Fitzpatrick<td>Regional Director<td>London<td>$385,750<tr><td>Michael Silva<td>Marketing Designer<td>London<td>$198,500<tr><td>Paul Byrd<td>Chief Financial Officer (CFO)<td>New York<td>$725,000<tr><td>Gloria Little<td>Systems Administrator<td>New York<td>$237,500<tr><td>Bradley Greer<td>Software Engineer<td>London<td>$132,000<tr><td>Dai Rios<td>Personnel Lead<td>Edinburgh<td>$217,500<tr><td>Jenette Caldwell<td>Development Lead<td>New York<td>$345,000<tr><td>Yuri Berry<td>Chief Marketing Officer (CMO)<td>New York<td>$675,000<tr><td>Caesar Vance<td>Pre-Sales Support<td>New York<td>$106,450<tr><td>Doris Wilder<td>Sales Assistant<td>Sidney<td>$85,600<tr><td>Angelica Ramos<td>Chief Executive Officer (CEO)<td>London<td>$1,200,000<tr><td>Gavin Joyce<td>Developer<td>Edinburgh<td>$92,575<tr><td>Jennifer Chang<td>Regional Director<td>Singapore<td>$357,650<tr><td>Brenden Wagner<td>Software Engineer<td>San Francisco<td>$206,850<tr><td>Fiona Green<td>Chief Operating Officer (COO)<td>San Francisco<td>$850,000<tr><td>Shou Itou<td>Regional Marketing<td>Tokyo<td>$163,000<tr><td>Michelle House<td>Integration Specialist<td>Sidney<td>$95,400<tr><td>Suki Burks<td>Developer<td>London<td>$114,500<tr><td>Prescott Bartlett<td>Technical Author<td>London<td>$145,000<tr><td>Gavin Cortez<td>Team Leader<td>San Francisco<td>$235,500<tr><td>Martena Mccray<td>Post-Sales support<td>Edinburgh<td>$324,050<tr><td>Unity Butler<td>Marketing Designer<td>San Francisco<td>$85,675<tr><td>Howard Hatfield<td>Office Manager<td>San Francisco<td>$164,500<tr><td>Hope Fuentes<td>Secretary<td>San Francisco<td>$109,850<tr><td>Vivian Harrell<td>Financial Controller<td>San Francisco<td>$452,500<tr><td>Timothy Mooney<td>Office Manager<td>London<td>$136,200<tr><td>Jackson Bradshaw<td>Director<td>New York<td>$645,750<tr><td>Olivia Liang<td>Support Engineer<td>Singapore<td>$234,500<tr><td>Bruno Nash<td>Software Engineer<td>London<td>$163,500<tr><td>Sakura Yamamoto<td>Support Engineer<td>Tokyo<td>$139,575<tr><td>Thor Walton<td>Developer<td>New York<td>$98,540<tr><td>Finn Camacho<td>Support Engineer<td>San Francisco<td>$87,500<tr><td>Serge Baldwin<td>Data Coordinator<td>Singapore<td>$138,575<tr><td>Zenaida Frank<td>Software Engineer<td>New York<td>$125,250<tr><td>Zorita Serrano<td>Software Engineer<td>San Francisco<td>$115,000<tr><td>Jennifer Acosta<td>Junior Javascript Developer<td>Edinburgh<td>$75,650<tr><td>Cara Stevens<td>Sales Assistant<td>New York<td>$145,600<tr><td>Hermione Butler<td>Regional Director<td>London<td>$356,250<tr><td>Lael Greer<td>Systems Administrator<td>London<td>$103,500<tr><td>Jonas Alexander<td>Developer<td>San Francisco<td>$86,500<tr><td>Shad Decker<td>Regional Director<td>Edinburgh<td>$183,000<tr><td>Michael Bruce<td>Javascript Developer<td>Singapore<td>$183,000<tr><td>Donna Snider<td>Customer Support<td>New York<td>$112,000</table></div><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/jquery.dataTables.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/dataTables.bootstrap.min.js></script>
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Bootstrap 4 with DataTables Example: Bootstrap Docs & DataTables Docs

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$(document).ready(function() {
  $('#example').DataTable();
});
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<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/css/dataTables.bootstrap4.min.css rel=stylesheet><div class=container><h1>Bootstrap 4 DataTables</h1><table cellspacing=0 class="table table-bordered table-hover table-inverse table-striped"id=example width=100%><thead><tr><th>Name<th>Position<th>Office<th>Age<th>Start date<th>Salary<tfoot><tr><th>Name<th>Position<th>Office<th>Age<th>Start date<th>Salary<tbody><tr><td>Tiger Nixon<td>System Architect<td>Edinburgh<td>61<td>2011/04/25<td>$320,800<tr><td>Garrett Winters<td>Accountant<td>Tokyo<td>63<td>2011/07/25<td>$170,750<tr><td>Ashton Cox<td>Junior Technical Author<td>San Francisco<td>66<td>2009/01/12<td>$86,000<tr><td>Cedric Kelly<td>Senior Javascript Developer<td>Edinburgh<td>22<td>2012/03/29<td>$433,060<tr><td>Airi Satou<td>Accountant<td>Tokyo<td>33<td>2008/11/28<td>$162,700<tr><td>Brielle Williamson<td>Integration Specialist<td>New York<td>61<td>2012/12/02<td>$372,000<tr><td>Herrod Chandler<td>Sales Assistant<td>San Francisco<td>59<td>2012/08/06<td>$137,500<tr><td>Rhona Davidson<td>Integration Specialist<td>Tokyo<td>55<td>2010/10/14<td>$327,900<tr><td>Colleen Hurst<td>Javascript Developer<td>San Francisco<td>39<td>2009/09/15<td>$205,500<tr><td>Sonya Frost<td>Software Engineer<td>Edinburgh<td>23<td>2008/12/13<td>$103,600<tr><td>Jena Gaines<td>Office Manager<td>London<td>30<td>2008/12/19<td>$90,560<tr><td>Quinn Flynn<td>Support Lead<td>Edinburgh<td>22<td>2013/03/03<td>$342,000<tr><td>Charde Marshall<td>Regional Director<td>San Francisco<td>36<td>2008/10/16<td>$470,600<tr><td>Haley Kennedy<td>Senior Marketing Designer<td>London<td>43<td>2012/12/18<td>$313,500<tr><td>Tatyana Fitzpatrick<td>Regional Director<td>London<td>19<td>2010/03/17<td>$385,750<tr><td>Michael Silva<td>Marketing Designer<td>London<td>66<td>2012/11/27<td>$198,500<tr><td>Paul Byrd<td>Chief Financial Officer (CFO)<td>New York<td>64<td>2010/06/09<td>$725,000<tr><td>Gloria Little<td>Systems Administrator<td>New York<td>59<td>2009/04/10<td>$237,500<tr><td>Bradley Greer<td>Software Engineer<td>London<td>41<td>2012/10/13<td>$132,000<tr><td>Dai Rios<td>Personnel Lead<td>Edinburgh<td>35<td>2012/09/26<td>$217,500<tr><td>Jenette Caldwell<td>Development Lead<td>New York<td>30<td>2011/09/03<td>$345,000<tr><td>Yuri Berry<td>Chief Marketing Officer (CMO)<td>New York<td>40<td>2009/06/25<td>$675,000<tr><td>Caesar Vance<td>Pre-Sales Support<td>New York<td>21<td>2011/12/12<td>$106,450<tr><td>Doris Wilder<td>Sales Assistant<td>Sidney<td>23<td>2010/09/20<td>$85,600<tr><td>Angelica Ramos<td>Chief Executive Officer (CEO)<td>London<td>47<td>2009/10/09<td>$1,200,000<tr><td>Gavin Joyce<td>Developer<td>Edinburgh<td>42<td>2010/12/22<td>$92,575<tr><td>Jennifer Chang<td>Regional Director<td>Singapore<td>28<td>2010/11/14<td>$357,650<tr><td>Brenden Wagner<td>Software Engineer<td>San Francisco<td>28<td>2011/06/07<td>$206,850<tr><td>Fiona Green<td>Chief Operating Officer (COO)<td>San Francisco<td>48<td>2010/03/11<td>$850,000<tr><td>Shou Itou<td>Regional Marketing<td>Tokyo<td>20<td>2011/08/14<td>$163,000<tr><td>Michelle House<td>Integration Specialist<td>Sidney<td>37<td>2011/06/02<td>$95,400<tr><td>Suki Burks<td>Developer<td>London<td>53<td>2009/10/22<td>$114,500<tr><td>Prescott Bartlett<td>Technical Author<td>London<td>27<td>2011/05/07<td>$145,000<tr><td>Gavin Cortez<td>Team Leader<td>San Francisco<td>22<td>2008/10/26<td>$235,500<tr><td>Martena Mccray<td>Post-Sales support<td>Edinburgh<td>46<td>2011/03/09<td>$324,050<tr><td>Unity Butler<td>Marketing Designer<td>San Francisco<td>47<td>2009/12/09<td>$85,675<tr><td>Howard Hatfield<td>Office Manager<td>San Francisco<td>51<td>2008/12/16<td>$164,500<tr><td>Hope Fuentes<td>Secretary<td>San Francisco<td>41<td>2010/02/12<td>$109,850<tr><td>Vivian Harrell<td>Financial Controller<td>San Francisco<td>62<td>2009/02/14<td>$452,500<tr><td>Timothy Mooney<td>Office Manager<td>London<td>37<td>2008/12/11<td>$136,200<tr><td>Jackson Bradshaw<td>Director<td>New York<td>65<td>2008/09/26<td>$645,750<tr><td>Olivia Liang<td>Support Engineer<td>Singapore<td>64<td>2011/02/03<td>$234,500<tr><td>Bruno Nash<td>Software Engineer<td>London<td>38<td>2011/05/03<td>$163,500<tr><td>Sakura Yamamoto<td>Support Engineer<td>Tokyo<td>37<td>2009/08/19<td>$139,575<tr><td>Thor Walton<td>Developer<td>New York<td>61<td>2013/08/11<td>$98,540<tr><td>Finn Camacho<td>Support Engineer<td>San Francisco<td>47<td>2009/07/07<td>$87,500<tr><td>Serge Baldwin<td>Data Coordinator<td>Singapore<td>64<td>2012/04/09<td>$138,575<tr><td>Zenaida Frank<td>Software Engineer<td>New York<td>63<td>2010/01/04<td>$125,250<tr><td>Zorita Serrano<td>Software Engineer<td>San Francisco<td>56<td>2012/06/01<td>$115,000<tr><td>Jennifer Acosta<td>Junior Javascript Developer<td>Edinburgh<td>43<td>2013/02/01<td>$75,650<tr><td>Cara Stevens<td>Sales Assistant<td>New York<td>46<td>2011/12/06<td>$145,600<tr><td>Hermione Butler<td>Regional Director<td>London<td>47<td>2011/03/21<td>$356,250<tr><td>Lael Greer<td>Systems Administrator<td>London<td>21<td>2009/02/27<td>$103,500<tr><td>Jonas Alexander<td>Developer<td>San Francisco<td>30<td>2010/07/14<td>$86,500<tr><td>Shad Decker<td>Regional Director<td>Edinburgh<td>51<td>2008/11/13<td>$183,000<tr><td>Michael Bruce<td>Javascript Developer<td>Singapore<td>29<td>2011/06/27<td>$183,000<tr><td>Donna Snider<td>Customer Support<td>New York<td>27<td>2011/01/25<td>$112,000</table></div><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/jquery.dataTables.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/datatables/1.10.20/js/dataTables.bootstrap4.min.js></script>
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Bootstrap 3 with Bootstrap Table Example: Bootstrap Docs & Bootstrap Table Docs

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<link href=https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><link href=https://cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.16.0/bootstrap-table.min.css rel=stylesheet><table data-sort-name=stargazers_count data-sort-order=desc data-toggle=table data-url="https://api.github.com/users/wenzhixin/repos?type=owner&sort=full_name&direction=asc&per_page=100&page=1"><thead><tr><th data-field=name data-sortable=true>Name<th data-field=stargazers_count data-sortable=true>Stars<th data-field=forks_count data-sortable=true>Forks<th data-field=description data-sortable=true>Description</thead></table><script src=https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js></script><script src=https://cdnjs.cloudflare.com/ajax/libs/bootstrap-table/1.16.0/bootstrap-table.min.js></script>
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Bootstrap 3 with Bootstrap Sortable Example: Bootstrap Docs & Bootstrap Sortable Docs

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function randomDate(t,e){return new Date(t.getTime()+Math.random()*(e.getTime()-t.getTime()))}function randomName(){return["Jack","Peter","Frank","Steven"][Math.floor(4*Math.random())]+" "+["White","Jackson","Sinatra","Spielberg"][Math.floor(4*Math.random())]}function newTableRow(){var t=moment(randomDate(new Date(2e3,0,1),new Date)).format("D.M.YYYY"),e=Math.round(Math.random()*Math.random()*100*100)/100,a=Math.round(Math.random()*Math.random()*100*100)/100,r=Math.round(Math.random()*Math.random()*100*100)/100;return"<tr><td>"+randomName()+"</td><td>"+e+"</td><td>"+a+"</td><td>"+r+"</td><td>"+Math.round(100*(e+a+r))/100+"</td><td data-dateformat='D-M-YYYY'>"+t+"</td></tr>"}function customSort(){alert("Custom sort.")}!function(t,e){"use strict";"function"==typeof define&&define.amd?define("tinysort",function(){return e}):t.tinysort=e}(this,function(){"use strict";function t(t,e){for(var a,r=t.length,o=r;o--;)e(t[a=r-o-1],a)}function e(t,e,a){for(var o in e)(a||t[o]===r)&&(t[o]=e[o]);return t}function a(t,e,a){u.push({prepare:t,sort:e,sortBy:a})}var r,o=!1,n=null,s=window,d=s.document,i=parseFloat,l=/(-?\d+\.?\d*)\s*$/g,c=/(\d+\.?\d*)\s*$/g,u=[],f=0,h=0,p=String.fromCharCode(4095),m={selector:n,order:"asc",attr:n,data:n,useVal:o,place:"org",returns:o,cases:o,natural:o,forceStrings:o,ignoreDashes:o,sortFunction:n,useFlex:o,emptyEnd:o};return s.Element&&function(t){t.matchesSelector=t.matchesSelector||t.mozMatchesSelector||t.msMatchesSelector||t.oMatchesSelector||t.webkitMatchesSelector||function(t){for(var e=this,a=(e.parentNode||e.document).querySelectorAll(t),r=-1;a[++r]&&a[r]!=e;);return!!a[r]}}(Element.prototype),e(a,{loop:t}),e(function(a,s){function v(t){var a=!!t.selector,r=a&&":"===t.selector[0],o=e(t||{},m);E.push(e({hasSelector:a,hasAttr:!(o.attr===n||""===o.attr),hasData:o.data!==n,hasFilter:r,sortReturnNumber:"asc"===o.order?1:-1},o))}function b(t,e,a){for(var r=a(t.toString()),o=a(e.toString()),n=0;r[n]&&o[n];n++)if(r[n]!==o[n]){var s=Number(r[n]),d=Number(o[n]);return s==r[n]&&d==o[n]?s-d:r[n]>o[n]?1:-1}return r.length-o.length}function g(t){for(var e,a,r=[],o=0,n=-1,s=0;e=(a=t.charAt(o++)).charCodeAt(0);){var d=46==e||e>=48&&57>=e;d!==s&&(r[++n]="",s=d),r[n]+=a}return r}function w(){return Y.forEach(function(t){F.appendChild(t.elm)}),F}function S(t){var e=t.elm,a=d.createElement("div");return t.ghost=a,e.parentNode.insertBefore(a,e),t}function y(t,e){var a=t.ghost,r=a.parentNode;r.insertBefore(e,a),r.removeChild(a),delete t.ghost}function C(t,e){var a,r=t.elm;return e.selector&&(e.hasFilter?r.matchesSelector(e.selector)||(r=n):r=r.querySelector(e.selector)),e.hasAttr?a=r.getAttribute(e.attr):e.useVal?a=r.value||r.getAttribute("value"):e.hasData?a=r.getAttribute("data-"+e.data):r&&(a=r.textContent),M(a)&&(e.cases||(a=a.toLowerCase()),a=a.replace(/\s+/g," ")),null===a&&(a=p),a}function M(t){return"string"==typeof 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t.elm})},{plugin:a,defaults:m})}()),function(t,e){"function"==typeof define&&define.amd?define(["jquery","tinysort","moment"],e):e(t.jQuery,t.tinysort,t.moment||void 0)}(this,function(t,e,a){var r,o,n,s=t(document);function d(e){var s=void 0!==a;r=e.sign?e.sign:"arrow","default"==e.customSort&&(e.customSort=c),o=e.customSort||o||c,n=e.emptyEnd,t("table.sortable").each(function(){var r=t(this),o=!0===e.applyLast;r.find("span.sign").remove(),r.find("> thead [colspan]").each(function(){for(var e=parseFloat(t(this).attr("colspan")),a=1;a<e;a++)t(this).after('<th class="colspan-compensate">')}),r.find("> thead [rowspan]").each(function(){for(var e=t(this),a=parseFloat(e.attr("rowspan")),r=1;r<a;r++){var o=e.parent("tr"),n=o.next("tr"),s=o.children().index(e);n.children().eq(s).before('<th class="rowspan-compensate">')}}),r.find("> thead tr").each(function(e){t(this).find("th").each(function(a){var r=t(this);r.addClass("nosort").removeClass("up down"),r.attr("data-sortcolumn",a),r.attr("data-sortkey",a+"-"+e)})}),r.find("> thead .rowspan-compensate, .colspan-compensate").remove(),r.find("th").each(function(){var e=t(this);if(void 0!==e.attr("data-dateformat")&&s){var o=parseFloat(e.attr("data-sortcolumn"));r.find("td:nth-child("+(o+1)+")").each(function(){var r=t(this);r.attr("data-value",a(r.text(),e.attr("data-dateformat")).format("YYYY/MM/DD/HH/mm/ss"))})}else if(void 0!==e.attr("data-valueprovider")){o=parseFloat(e.attr("data-sortcolumn"));r.find("td:nth-child("+(o+1)+")").each(function(){var a=t(this);a.attr("data-value",new RegExp(e.attr("data-valueprovider")).exec(a.text())[0])})}}),r.find("td").each(function(){var e=t(this);void 0!==e.attr("data-dateformat")&&s?e.attr("data-value",a(e.text(),e.attr("data-dateformat")).format("YYYY/MM/DD/HH/mm/ss")):void 0!==e.attr("data-valueprovider")?e.attr("data-value",new RegExp(e.attr("data-valueprovider")).exec(e.text())[0]):void 0===e.attr("data-value")&&e.attr("data-value",e.text())});var n=l(r),d=n.bsSort;r.find('> thead th[data-defaultsort!="disabled"]').each(function(e){var a=t(this),r=a.closest("table.sortable");a.data("sortTable",r);var s=a.attr("data-sortkey"),i=o?n.lastSort:-1;d[s]=o?d[s]:a.attr("data-defaultsort"),void 0!==d[s]&&o===(s===i)&&(d[s]="asc"===d[s]?"desc":"asc",u(a,r))})})}function i(e){var a=t(e),r=a.data("sortTable")||a.closest("table.sortable");u(a,r)}function l(e){var a=e.data("bootstrap-sortable-context");return void 0===a&&(a={bsSort:[],lastSort:void 0},e.find('> thead th[data-defaultsort!="disabled"]').each(function(e){var r=t(this),o=r.attr("data-sortkey");a.bsSort[o]=r.attr("data-defaultsort"),void 0!==a.bsSort[o]&&(a.lastSort=o)}),e.data("bootstrap-sortable-context",a)),a}function c(t,a){e(t,a)}function u(e,a){a.trigger("before-sort");var s=parseFloat(e.attr("data-sortcolumn")),d=l(a),i=d.bsSort;if(e.attr("colspan")){var c=parseFloat(e.data("mainsort"))||0,f=parseFloat(e.data("sortkey").split("-").pop());if(a.find("> thead tr").length-1>f)return void u(a.find('[data-sortkey="'+(s+c)+"-"+(f+1)+'"]'),a);s+=c}var h=e.attr("data-defaultsign")||r;if(a.find("> thead th").each(function(){t(this).removeClass("up").removeClass("down").addClass("nosort")}),t.browser.mozilla){var p=a.find("> thead div.mozilla");void 0!==p&&(p.find(".sign").remove(),p.parent().html(p.html())),e.wrapInner('<div class="mozilla"></div>'),e.children().eq(0).append('<span class="sign '+h+'"></span>')}else a.find("> thead span.sign").remove(),e.append('<span class="sign '+h+'"></span>');var m=e.attr("data-sortkey"),v="desc"!==e.attr("data-firstsort")?"desc":"asc",b=i[m]||v;d.lastSort!==m&&void 0!==i[m]||(b="asc"===b?"desc":"asc"),i[m]=b,d.lastSort=m,"desc"===i[m]?(e.find("span.sign").addClass("up"),e.addClass("up").removeClass("down nosort")):e.addClass("down").removeClass("up nosort");var g=a.children("tbody").children("tr"),w=[];t(g.filter('[data-disablesort="true"]').get().reverse()).each(function(e,a){var r=t(a);w.push({index:g.index(r),row:r}),r.remove()});var S=g.not('[data-disablesort="true"]');if(0!=S.length){var y="asc"===i[m]&&n;o(S,{emptyEnd:y,selector:"td:nth-child("+(s+1)+")",order:i[m],data:"value"})}t(w.reverse()).each(function(t,e){0===e.index?a.children("tbody").prepend(e.row):a.children("tbody").children("tr").eq(e.index-1).after(e.row)}),a.find("> tbody > tr > td.sorted,> thead th.sorted").removeClass("sorted"),S.find("td:eq("+s+")").addClass("sorted"),e.addClass("sorted"),a.trigger("sorted")}if(t.bootstrapSortable=function(t){null==t?d({}):t.constructor===Boolean?d({applyLast:t}):void 0!==t.sortingHeader?i(t.sortingHeader):d(t)},s.on("click",'table.sortable>thead th[data-defaultsort!="disabled"]',function(t){i(this)}),!t.browser){t.browser={chrome:!1,mozilla:!1,opera:!1,msie:!1,safari:!1};var f=navigator.userAgent;t.each(t.browser,function(e){t.browser[e]=!!new RegExp(e,"i").test(f),t.browser.mozilla&&"mozilla"===e&&(t.browser.mozilla=!!new RegExp("firefox","i").test(f)),t.browser.chrome&&"safari"===e&&(t.browser.safari=!1)})}t(t.bootstrapSortable)}),function(){var t=$("table");t.append(newTableRow()),t.append(newTableRow()),$("button.add-row").on("click",function(){var e=$(this);t.append(newTableRow()),e.data("sort")?$.bootstrapSortable(!0):$.bootstrapSortable(!1)}),$("button.change-sort").on("click",function(){$(this).data("custom")?$.bootstrapSortable(!0,void 0,customSort):$.bootstrapSortable(!0,void 0,"default")}),t.on("sorted",function(){alert("Table was sorted.")}),$("#event").on("change",function(){$(this).is(":checked")?t.on("sorted",function(){alert("Table was sorted.")}):t.off("sorted")}),$("input[name=sign]:radio").change(function(){$.bootstrapSortable(!0,$(this).val())})}();
_x000D_
table.sortable span.sign { display: block; position: absolute; top: 50%; right: 5px; font-size: 12px; margin-top: -10px; color: #bfbfc1; } table.sortable th:after { display: block; position: absolute; top: 50%; right: 5px; font-size: 12px; margin-top: -10px; color: #bfbfc1; } table.sortable th.arrow:after { content: ''; } table.sortable span.arrow, span.reversed, th.arrow.down:after, th.reversedarrow.down:after, th.arrow.up:after, th.reversedarrow.up:after { border-style: solid; border-width: 5px; font-size: 0; border-color: #ccc transparent transparent transparent; line-height: 0; height: 0; width: 0; margin-top: -2px; } table.sortable span.arrow.up, th.arrow.up:after { border-color: transparent transparent #ccc transparent; margin-top: -7px; } table.sortable span.reversed, th.reversedarrow.down:after { border-color: transparent transparent #ccc transparent; margin-top: -7px; } table.sortable span.reversed.up, th.reversedarrow.up:after { border-color: #ccc transparent transparent transparent; margin-top: -2px; } table.sortable span.az:before, th.az.down:after { content: "a .. z"; } table.sortable span.az.up:before, th.az.up:after { content: "z .. a"; } table.sortable th.az.nosort:after, th.AZ.nosort:after, th._19.nosort:after, th.month.nosort:after { content: ".."; } table.sortable span.AZ:before, th.AZ.down:after { content: "A .. Z"; } table.sortable span.AZ.up:before, th.AZ.up:after { content: "Z .. A"; } table.sortable span._19:before, th._19.down:after { content: "1 .. 9"; } table.sortable span._19.up:before, th._19.up:after { content: "9 .. 1"; } table.sortable span.month:before, th.month.down:after { content: "jan .. dec"; } table.sortable span.month.up:before, th.month.up:after { content: "dec .. jan"; } table.sortable thead th:not([data-defaultsort=disabled]) { cursor: pointer; position: relative; top: 0; left: 0; } table.sortable thead th:hover:not([data-defaultsort=disabled]) { background: #efefef; } table.sortable thead th div.mozilla { position: relative; }
_x000D_
<link href=https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.13.1/css/all.min.css rel=stylesheet><link href=https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css rel=stylesheet><div class=container><div class=hero-unit><h1>Bootstrap Sortable</h1></div><table class="sortable table table-bordered table-striped"><thead><tr><th style=width:20%;vertical-align:middle data-defaultsign=nospan class=az data-defaultsort=asc rowspan=2><i class="fa fa-fw fa-map-marker"></i>Name<th style=text-align:center colspan=4 data-mainsort=3>Results<th data-defaultsort=disabled><tr><th style=width:20% colspan=2 data-mainsort=1 data-firstsort=desc>Round 1<th style=width:20%>Round 2<th style=width:20%>Total<t
                  

MongoDB vs. Cassandra

Lots of reads in every query, fewer regular writes

Both databases perform well on reads where the hot data set fits in memory. Both also emphasize join-less data models (and encourage denormalization instead), and both provide indexes on documents or rows, although MongoDB's indexes are currently more flexible.

Cassandra's storage engine provides constant-time writes no matter how big your data set grows. Writes are more problematic in MongoDB, partly because of the b-tree based storage engine, but more because of the multi-granularity locking it does.

For analytics, MongoDB provides a custom map/reduce implementation; Cassandra provides native Hadoop support, including for Hive (a SQL data warehouse built on Hadoop map/reduce) and Pig (a Hadoop-specific analysis language that many think is a better fit for map/reduce workloads than SQL). Cassandra also supports use of Spark.

Not worried about "massive" scalability

If you're looking at a single server, MongoDB is probably a better fit. For those more concerned about scaling, Cassandra's no-single-point-of-failure architecture will be easier to set up and more reliable. (MongoDB's global write lock tends to become more painful, too.) Cassandra also gives a lot more control over how your replication works, including support for multiple data centers.

More concerned about simple setup, maintenance and code

Both are trivial to set up, with reasonable out-of-the-box defaults for a single server. Cassandra is simpler to set up in a multi-server configuration since there are no special-role nodes to worry about.

If you're presently using JSON blobs, MongoDB is an insanely good match for your use case, given that it uses BSON to store the data. You'll be able to have richer and more queryable data than you would in your present database. This would be the most significant win for Mongo.

JPA: unidirectional many-to-one and cascading delete

Relationships in JPA are always unidirectional, unless you associate the parent with the child in both directions. Cascading REMOVE operations from the parent to the child will require a relation from the parent to the child (not just the opposite).

You'll therefore need to do this:

  • Either, change the unidirectional @ManyToOne relationship to a bi-directional @ManyToOne, or a unidirectional @OneToMany. You can then cascade REMOVE operations so that EntityManager.remove will remove the parent and the children. You can also specify orphanRemoval as true, to delete any orphaned children when the child entity in the parent collection is set to null, i.e. remove the child when it is not present in any parent's collection.
  • Or, specify the foreign key constraint in the child table as ON DELETE CASCADE. You'll need to invoke EntityManager.clear() after calling EntityManager.remove(parent) as the persistence context needs to be refreshed - the child entities are not supposed to exist in the persistence context after they've been deleted in the database.

How to implement authenticated routes in React Router 4?

const Root = ({ session }) => {
  const isLoggedIn = session && session.getCurrentUser
  return (
    <Router>
      {!isLoggedIn ? (
        <Switch>
          <Route path="/signin" component={<Signin />} />
          <Redirect to="/signin" />
        </Switch>
      ) : (
        <Switch>
          <Route path="/" exact component={Home} />
          <Route path="/about" component={About} />
          <Route path="/something-else" component={SomethingElse} />
          <Redirect to="/" />
        </Switch>
      )}
    </Router>
  )
}

How to force deletion of a python object?

  1. Add an exit handler that closes all the bars.
  2. __del__() gets called when the number of references to an object hits 0 while the VM is still running. This may be caused by the GC.
  3. If __init__() raises an exception then the object is assumed to be incomplete and __del__() won't be invoked.

Accessing member of base class

You are incorrectly using the super and this keyword. Here is an example of how they work:

class Animal {
    public name: string;
    constructor(name: string) { 
        this.name = name;
    }
    move(meters: number) {
        console.log(this.name + " moved " + meters + "m.");
    }
}

class Horse extends Animal {
    move() {
        console.log(super.name + " is Galloping...");
        console.log(this.name + " is Galloping...");
        super.move(45);
    }
}

var tom: Animal = new Horse("Tommy the Palomino");

Animal.prototype.name = 'horseee'; 

tom.move(34);
// Outputs:

// horseee is Galloping...
// Tommy the Palomino is Galloping...
// Tommy the Palomino moved 45m.

Explanation:

  1. The first log outputs super.name, this refers to the prototype chain of the object tom, not the object tom self. Because we have added a name property on the Animal.prototype, horseee will be outputted.
  2. The second log outputs this.name, the this keyword refers to the the tom object itself.
  3. The third log is logged using the move method of the Animal base class. This method is called from Horse class move method with the syntax super.move(45);. Using the super keyword in this context will look for a move method on the prototype chain which is found on the Animal prototype.

Remember TS still uses prototypes under the hood and the class and extends keywords are just syntactic sugar over prototypical inheritance.

How to find the date of a day of the week from a date using PHP?

<?php echo date("H:i", time()); ?>
<?php echo $days[date("l", time())] . date(", d.m.Y", time()); ?>

Simple, this should do the trick

What does "Object reference not set to an instance of an object" mean?

If I have the class:

public class MyClass
{
   public void MyMethod()
   {

   }
}

and I then do:

MyClass myClass = null;
myClass.MyMethod();

The second line throws this exception becuase I'm calling a method on a reference type object that is null (I.e. has not been instantiated by calling myClass = new MyClass())

^[A-Za-Z ][A-Za-z0-9 ]* regular expression?

^[A-Za-z](\W|\w)*

(\W|\w) will ensure that every subsequent letter is word(\w) or non word(\W)

instead of (\W|\w)* you can also use .* where . means absolutely anything just like (\w|\W)

How do I jump to a closing bracket in Visual Studio Code?

In german VS-Environments(here 2015): Optionen/Umgebung/Tastatur. (english: options/environment/keyboard). Show Commands With "GeheZuKlammer" (english: "GoToBracket"). Set your own Shortcut.

How to execute a shell script from C in Linux?

I prefer fork + execlp for "more fine-grade" control as doron mentioned. Example code shown below.

Store you command in a char array parameters, and malloc space for the result.

int fd[2];
pipe(fd);
if ( (childpid = fork() ) == -1){
   fprintf(stderr, "FORK failed");
   return 1;
} else if( childpid == 0) {
   close(1);
   dup2(fd[1], 1);
   close(fd[0]);
   execlp("/bin/sh","/bin/sh","-c",parameters,NULL);
}
wait(NULL);
read(fd[0], result, RESULT_SIZE);
printf("%s\n",result);

How to get a cross-origin resource sharing (CORS) post request working

REQUEST:

 $.ajax({
            url: "http://localhost:8079/students/add/",
            type: "POST",
            crossDomain: true,
            data: JSON.stringify(somejson),
            dataType: "json",
            success: function (response) {
                var resp = JSON.parse(response)
                alert(resp.status);
            },
            error: function (xhr, status) {
                alert("error");
            }
        });

RESPONSE:

response = HttpResponse(json.dumps('{"status" : "success"}'))
response.__setitem__("Content-type", "application/json")
response.__setitem__("Access-Control-Allow-Origin", "*")

return response

map vs. hash_map in C++

Some of the key differences are in the complexity requirements.

  • A map requires O(log(N)) time for inserts and finds operations, as it's implemented as a Red-Black Tree data structure.

  • An unordered_map requires an 'average' time of O(1) for inserts and finds, but is allowed to have a worst-case time of O(N). This is because it's implemented using Hash Table data structure.

So, usually, unordered_map will be faster, but depending on the keys and the hash function you store, can become much worse.

Looping over a list in Python

Do this instead:

values = [[1,2,3],[4,5]]
for x in values:
    if len(x) == 3:
       print(x)

How to set default value to all keys of a dict object in python?

Not after creating it, no. But you could use a defaultdict in the first place, which sets default values when you initialize it.

Cross Domain Form POSTing

It is possible to build an arbitrary GET or POST request and send it to any server accessible to a victims browser. This includes devices on your local network, such as Printers and Routers.

There are many ways of building a CSRF exploit. A simple POST based CSRF attack can be sent using .submit() method. More complex attacks, such as cross-site file upload CSRF attacks will exploit CORS use of the xhr.withCredentals behavior.

CSRF does not violate the Same-Origin Policy For JavaScript because the SOP is concerned with JavaScript reading the server's response to a clients request. CSRF attacks don't care about the response, they care about a side-effect, or state change produced by the request, such as adding an administrative user or executing arbitrary code on the server.

Make sure your requests are protected using one of the methods described in the OWASP CSRF Prevention Cheat Sheet. For more information about CSRF consult the OWASP page on CSRF.

Python Traceback (most recent call last)

In Python2, input is evaluated, input() is equivalent to eval(raw_input()). When you enter klj, Python tries to evaluate that name and raises an error because that name is not defined.

Use raw_input to get a string from the user in Python2.

Demo 1: klj is not defined:

>>> input()
klj
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<string>", line 1, in <module>
NameError: name 'klj' is not defined

Demo 2: klj is defined:

>>> klj = 'hi'
>>> input()
klj
'hi'

Demo 3: getting a string with raw_input:

>>> raw_input()
klj
'klj'

Create directory if it does not exist

$path = "C:\temp\NewFolder"
If(!(test-path $path))
{
      New-Item -ItemType Directory -Force -Path $path
}

Test-Path checks to see if the path exists. When it does not, it will create a new directory.

Setting environment variables on OS X

Another, free, opensource, Mac OS X v10.8 (Mountain Lion) Preference pane/environment.plist solution is EnvPane.

EnvPane's source code available on GitHub. EnvPane looks like it has comparable features to RCEnvironment, however, it seems it can update its stored variables instantly, i.e. without the need for a restart or login, which is welcome.

As stated by the developer:

EnvPane is a preference pane for Mac OS X 10.8 (Mountain Lion) that lets you set environment variables for all programs in both graphical and terminal sessions. Not only does it restore support for ~/.MacOSX/environment.plist in Mountain Lion, it also publishes your changes to the environment immediately, without the need to log out and back in. <SNIP> EnvPane includes (and automatically installs) a launchd agent that runs 1) early after login and 2) whenever the ~/.MacOSX/environment.plist changes. The agent reads ~/.MacOSX/environment.plist and exports the environment variables from that file to the current user's launchd instance via the same API that is used by launchctl setenv and launchctl unsetenv.

Disclaimer: I am in no way related to the developer or his/her project.

P.S. I like the name (sounds like 'Ends Pain').

How to remove a package from Laravel using composer?

Normally composer remove used like this is enough:

$ composer remove vendor/package

but if composer package is removed and config cache is not cleaned you cannot clean it, when you try like so

php artisan config:clear

you can get an error In ProviderRepository.php line 208:

Class 'Laracasts\Flash\FlashServiceProvider' not found

this is a dead end, unless you go deleting files

$rm bootstrap/cache/config.php

And this is Laravel 5.6 I'm talking about, not some kind of very old stuff.

It happens usually on automated deployment, when you copy files of a new release on top of old cache. Even if you cleared cache before copying. You end up with old cache and a new composer.json.

open link of google play store in mobile version android

Open app page on Google Play:

Intent intent = new Intent(Intent.ACTION_VIEW,
                Uri.parse("market://details?id=" + context.getPackageName()));
startActivity(intent);

How do multiple clients connect simultaneously to one port, say 80, on a server?

First off, a "port" is just a number. All a "connection to a port" really represents is a packet which has that number specified in its "destination port" header field.

Now, there are two answers to your question, one for stateful protocols and one for stateless protocols.

For a stateless protocol (ie UDP), there is no problem because "connections" don't exist - multiple people can send packets to the same port, and their packets will arrive in whatever sequence. Nobody is ever in the "connected" state.

For a stateful protocol (like TCP), a connection is identified by a 4-tuple consisting of source and destination ports and source and destination IP addresses. So, if two different machines connect to the same port on a third machine, there are two distinct connections because the source IPs differ. If the same machine (or two behind NAT or otherwise sharing the same IP address) connects twice to a single remote end, the connections are differentiated by source port (which is generally a random high-numbered port).

Simply, if I connect to the same web server twice from my client, the two connections will have different source ports from my perspective and destination ports from the web server's. So there is no ambiguity, even though both connections have the same source and destination IP addresses.

Ports are a way to multiplex IP addresses so that different applications can listen on the same IP address/protocol pair. Unless an application defines its own higher-level protocol, there is no way to multiplex a port. If two connections using the same protocol simultaneously have identical source and destination IPs and identical source and destination ports, they must be the same connection.

Date ticks and rotation in matplotlib

Simply use

ax.set_xticklabels(label_list, rotation=45)

mongodb/mongoose findMany - find all documents with IDs listed in array

This code works for me just fine as of mongoDB v4.2 and mongoose 5.9.9:

const Ids = ['id1','id2','id3']
const results = await Model.find({ _id: Ids})

and the Ids can be of type ObjectId or String

Android - Share on Facebook, Twitter, Mail, ecc

yes you can ... you just need to know the exact package name of the application:

  • Facebook - "com.facebook.katana"
  • Twitter - "com.twitter.android"
  • Instagram - "com.instagram.android"
  • Pinterest - "com.pinterest"

And you can create the intent like this

Intent intent = context.getPackageManager().getLaunchIntentForPackage(application);
if (intent != null) {
     // The application exists
     Intent shareIntent = new Intent();
     shareIntent.setAction(Intent.ACTION_SEND);
     shareIntent.setPackage(application);

     shareIntent.putExtra(android.content.Intent.EXTRA_TITLE, title);
     shareIntent.putExtra(Intent.EXTRA_TEXT, description);
     // Start the specific social application
     context.startActivity(shareIntent);
} else {
    // The application does not exist
    // Open GooglePlay or use the default system picker
}

How to create global variables accessible in all views using Express / Node.JS?

you can also use "global"

Example:

declare like this :

  app.use(function(req,res,next){
      global.site_url = req.headers.host;   // hostname = 'localhost:8080'
      next();
   });

Use like this: in any views or ejs file <% console.log(site_url); %>

in js files console.log(site_url);

How to keep a VMWare VM's clock in sync?

according to VMware's knowledge base, the actual solution depends on the Linux distro and release, in RHEL 5.3 I usually edit /etc/grub.conf and append this parameters to the kernel entry: divider=10 clocksource=acpi_pm

Then enable NTP, disable VMware time synchronization from vmware-toolbox and finally reboot the VM

A complete table with guidelines for each Linux distro can be found here:

TIMEKEEPING BEST PRACTICES FOR LINUX GUESTS http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006427

How to kill all processes with a given partial name?

If you need more flexibility in selecting the processes use

for KILLPID in `ps ax | grep 'my_pattern' | awk ' { print $1;}'`; do 
  kill -9 $KILLPID;
done

You can use grep -e etc.

What are the differences between json and simplejson Python modules?

simplejson module is simply 1,5 times faster than json (On my computer, with simplejson 2.1.1 and Python 2.7 x86).

If you want, you can try the benchmark: http://abral.altervista.org/jsonpickle-bench.zip On my PC simplejson is faster than cPickle. I would like to know also your benchmarks!

Probably, as said Coady, the difference between simplejson and json is that simplejson includes _speedups.c. So, why don't python developers use simplejson?

How to escape the % (percent) sign in C's printf?

You can escape it by posting a double '%' like this: %%

Using your example:

printf("hello%%");

Escaping '%' sign is only for printf. If you do:

char a[5];
strcpy(a, "%%");
printf("This is a's value: %s\n", a);

It will print: This is a's value: %%

How can I style even and odd elements?

Below is the example of even and odd css color apply

<html>
<head>
<style> 
p:nth-child(even) {
    background: red;
}
p:nth-child(odd) {
    background: green;
}
</style>
</head>
<body>

<p>The first Odd.</p>
<p>The second Even.</p>
<p>The third Odd.</p>
<p>The fourth Even.</p>


</body>
</html>

"The remote certificate is invalid according to the validation procedure." using Gmail SMTP server

Are you sure you are using correct SMTP server address?

Both smtp.google.com and smtp.gmail.com work, but SSL certificate is issued to the second one.

mcrypt is deprecated, what is the alternative?

I was able to translate my Crypto object

  • Get a copy of php with mcrypt to decrypt the old data. I went to http://php.net/get/php-7.1.12.tar.gz/from/a/mirror, compiled it, then added the ext/mcrypt extension (configure;make;make install). I think I had to add the extenstion=mcrypt.so line to the php.ini as well. A series of scripts to build intermediate versions of the data with all data unencrypted.

  • Build a public and private key for openssl

    openssl genrsa -des3 -out pkey.pem 2048
    (set a password)
    openssl rsa -in pkey.pem -out pkey-pub.pem -outform PEM -pubout
    
  • To Encrypt (using public key) use openssl_seal. From what I've read, openssl_encrypt using an RSA key is limited to 11 bytes less than the key length (See http://php.net/manual/en/function.openssl-public-encrypt.php comment by Thomas Horsten)

    $pubKey = openssl_get_publickey(file_get_contents('./pkey-pub.pem'));
    openssl_seal($pwd, $sealed, $ekeys, [ $pubKey ]);
    $encryptedPassword = base64_encode($sealed);
    $key = base64_encode($ekeys[0]);
    

You could probably store the raw binary.

  • To Decrypt (using private key)

    $passphrase="passphrase here";
    $privKey = openssl_get_privatekey(file_get_contents('./pkey.pem'), $passphrase);
    // I base64_decode() from my db columns
    openssl_open($encryptedPassword, $plain, $key, $privKey);
    echo "<h3>Password=$plain</h3>";
    

P.S. You can't encrypt the empty string ("")

P.P.S. This is for a password database not for user validation.

Jquery ajax call click event submit button

You did not add # before id of the button. You do not have right selector in your jquery code. So jquery is never execute in your button click. its submitted your form directly not passing any ajax request.

See documentation: http://api.jquery.com/category/selectors/
its your friend.

Try this:

It seems that id: $("#Shareitem").val() is wrong if you want to pass the value of

<input type="hidden" name="id" value="" id="id">

you need to change this line:

id: $("#Shareitem").val()

by

id: $("#id").val()

All together:

 <script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
    <script>
    $(document).ready(function(){
      $("#Shareitem").click(function(e){
          e.preventDefault();
        $.ajax({type: "POST",
                url: "/imball-reagens/public/shareitem",
                data: { id: $("#Shareitem").val(), access_token: $("#access_token").val() },
                success:function(result){
          $("#sharelink").html(result);
        }});
      });
    });
    </script>

React Native: How to select the next TextInput after pressing the "next" keyboard button?

Really annoying that RN doesn't have some sort of Tabindex system.

A functional component, for my use case, I have an array of string IDs for inputs which I iterate through and show one text input each. The following code will automatically jump the user through all of them, stopping the keyboard from disappearing/reappearing between fields and dismissing it at the end, also showing the appropriate "action" button on the keyboard.

Typescript, Native Base.

_x000D_
_x000D_
const stringFieldIDs = [
  'q1', 'q2', 'q3'
];

export default () => {
  const stringFieldRefs = stringFieldIDs.map(() => useRef < any > ());

  const basicStringField = (id: string, ind: number) => {
    const posInd = stringFieldIDs.indexOf(id);
    const isLast = posInd === stringFieldIDs.length - 1;

    return ( <
      Input blurOnSubmit = {
        isLast
      }
      ref = {
        stringFieldRefs[posInd]
      }
      returnKeyType = {
        isLast ? 'done' : 'next'
      }
      onSubmitEditing = {
        isLast ?
        undefined :
          () => stringFieldRefs[posInd + 1].current._root.focus()
      }
      />
    );
  };

  return stringFieldIDs.map(basicStringField);
};
_x000D_
_x000D_
_x000D_

How to add elements of a Java8 stream into an existing List

Erik Allik already gave very good reasons, why you will most likely not want to collect elements of a stream into an existing List.

Anyway, you can use the following one-liner, if you really need this functionality.

But as Stuart Marks explains in his answer, you should never do this, if the streams might be parallel streams - use at your own risk...

list.stream().collect(Collectors.toCollection(() -> myExistingList));

How to get the CPU Usage in C#?

You can use WMI to get CPU percentage information. You can even log into a remote computer if you have the correct permissions. Look at http://www.csharphelp.com/archives2/archive334.html to get an idea of what you can accomplish.

Also helpful might be the MSDN reference for the Win32_Process namespace.

See also a CodeProject example How To: (Almost) Everything In WMI via C#.

delete map[key] in go?

delete(sessions, "anykey")

These days, nothing will crash.

Copy array by value

This is how I've done it after trying many approaches:

var newArray = JSON.parse(JSON.stringify(orgArray));

This will create a new deep copy not related to the first one (not a shallow copy).

Also this obviously will not clone events and functions, but the good thing you can do it in one line, and it can be used for any kind of object (arrays, strings, numbers, objects ...)

How to set the default value of an attribute on a Laravel model

You can set Default attribute in Model also>

protected $attributes = [
        'status' => self::STATUS_UNCONFIRMED,
        'role_id' => self::ROLE_PUBLISHER,
    ];

You can find the details in these links

1.) How to set a default attribute value for a Laravel / Eloquent model?

2.) https://laracasts.com/index.php/discuss/channels/eloquent/eloquent-help-generating-attribute-values-before-creating-record


You can also Use Accessors & Mutators for this You can find the details in the Laravel documentation 1.) https://laravel.com/docs/4.2/eloquent#accessors-and-mutators

2.) https://scotch.io/tutorials/automatically-format-laravel-database-fields-with-accessors-and-mutators

3.) Universal accessors and mutators in Laravel 4

Bootstrap modal appearing under background

In my case, the cause was boostrap.min.css. Once I excluded it from my HTML file as a reference, the dialog showed in front of the modal shade.

Making a Sass mixin with optional arguments

A so much better DRY way

is to pass $args... to the @mixin. That way, no matter how many $args you will pass. In the @input call, you can pass all args needed. Like so:

@mixin box-shadow($args...) {
  -webkit-box-shadow: $args;
  -moz-box-shadow: $args;
  box-shadow: $args;
}

And now you can reuse your box-shadow in every class you want by passing all needed args:

.my-box-shadow {
  @include box-shadow(2px 2px 5px #555, inset 0 0 0);
}

'ng' is not recognized as an internal or external command, operable program or batch file

No need to uninstall angular/cli.

  1. You just need to make sure the PATH to npm is in your environment PATH and at the top.

C:\Users\yourusername\AppData\Roaming\npm

  1. Then close whatever git or command client your using and run ng-v again and should work

How to remove list elements in a for loop in Python?

You are not permitted to remove elements from the list while iterating over it using a for loop.

The best way to rewrite the code depends on what it is you're trying to do.

For example, your code is equivalent to:

for item in a:
  print item
a[:] = []

Alternatively, you could use a while loop:

while a:
  print a.pop(0)

I'm trying to remove items if they match a condition. Then I go to next item.

You could copy every element that doesn't match the condition into a second list:

result = []
for item in a:
  if condition is False:
    result.append(item)
a = result

Alternatively, you could use filter or a list comprehension and assign the result back to a:

a = filter(lambda item:... , a)

or

a = [item for item in a if ...]

where ... stands for the condition that you need to check.

Functions that return a function

Returning b is returning a function object. In Javascript, functions are just objects, like any other object. If you find that not helpful, just replace the word "object" with "thing". You can return any object from a function. You can return a true/false value. An integer (1,2,3,4...). You can return a string. You can return a complex object with multiple properties. And you can return a function. a function is just a thing.

In your case, returning b returns the thing, the thing is a callable function. Returning b() returns the value returned by the callable function.

Consider this code:

function b() {
   return 42;
}

Using the above definition, return b(); returns the value 42. On the other hand return b; returns a function, that itself returns the value of 42. They are two different things.

Delete newline in Vim

While on the upper line in normal mode, hit Shift+j.

You can prepend a count too, so 3J on the top line would join all those lines together.

How to get the system uptime in Windows?

I use this little PowerShell snippet:

function Get-SystemUptime {
    $operatingSystem = Get-WmiObject Win32_OperatingSystem
    "$((Get-Date) - ([Management.ManagementDateTimeConverter]::ToDateTime($operatingSystem.LastBootUpTime)))"
}

which then yields something like the following:

PS> Get-SystemUptime
6.20:40:40.2625526

"date(): It is not safe to rely on the system's timezone settings..."

I am hosting my EC2 and S3 bucket in us-west-2 (Oregon) region. When I was calling $s3client->listBuckets() to list existing buckets in my php, I was getting exception - "Uncaught exception 'Exception' with message 'DateTime::__construct(): It is not safe to rely on the system's timezone settings...". I made below changes to make it work. Sharing these details in case someone is facing similar issue and any of above answers have not helped.

  1. Based on documentation @ AWS Configuring Network Time Protocol (NTP), I confirmed ntpd service status is fine by running ntpstat command. If you get error, this link helps you to know what is going wrong.
  2. Opened /etc/php.ini file (some may have it in different path based on version of php installed) and found that date.timezone was not set to any value and also it was commented by default. I un-commented by removing ';' before this line and set its value to "UTC" and saved the file.
  3. Restarted http and ntp daemons using sudo service httpd restart and sudo service ntpd restart commands.

After this I am able to list buckets successfully without any exception. Hope this helps.

Converting List<Integer> to List<String>

To the people concerned about "boxing" in jsight's answer: there is none. String.valueOf(Object) is used here, and no unboxing to int is ever performed.

Whether you use Integer.toString() or String.valueOf(Object) depends on how you want to handle possible nulls. Do you want to throw an exception (probably), or have "null" Strings in your list (maybe). If the former, do you want to throw a NullPointerException or some other type?

Also, one small flaw in jsight's response: List is an interface, you can't use the new operator on it. I would probably use a java.util.ArrayList in this case, especially since we know up front how long the list is likely to be.

Git Commit Messages: 50/72 Formatting

Is the maximum recommended title length really 50?

I have believed this for years, but as I just noticed the documentation of "git commit" actually states

$ git help commit | grep -C 1 50
      Though not required, it’s a good idea to begin the commit message with
      a single short (less than 50 character) line summarizing the change,
      followed by a blank line and then a more thorough description. The text

$  git version
git version 2.11.0

One could argue that "less then 50" can only mean "no longer than 49".

Using Mockito to stub and execute methods for testing

You are confusing a Mock with a Spy.

In a mock all methods are stubbed and return "smart return types". This means that calling any method on a mocked class will do nothing unless you specify behaviour.

In a spy the original functionality of the class is still there but you can validate method invocations in a spy and also override method behaviour.

What you want is

MyProcessingAgent mockMyAgent = Mockito.spy(MyProcessingAgent.class);

A quick example:

static class TestClass {

    public String getThing() {
        return "Thing";
    }

    public String getOtherThing() {
        return getThing();
    }
}

public static void main(String[] args) {
    final TestClass testClass = Mockito.spy(new TestClass());
    Mockito.when(testClass.getThing()).thenReturn("Some Other thing");
    System.out.println(testClass.getOtherThing());
}

Output is:

Some Other thing

NB: You should really try to mock the dependencies for the class being tested not the class itself.

Android-Studio upgraded from 0.1.9 to 0.2.0 causing gradle build errors now

Ok, I finally resolved this, by completely de-installing Android-Studio, and then installing the latest (0.2.0) from scratch.

EDIT: I also had to use the Android SDK-Manager, and install the component in the 'Extras' section called the Android Support Repository (as mentioned elsewhere).

Note: This does NOT fix my old existing project...that one still will not build, as indicated above.

But, it DOES solve the issue of now being able to at least create NEW projects going forward, that build ok using 'Gradle'. (So, basically, I re-created my proj from scratch under a new name, and copied all my code and project xml-files, etc, from the old project, into the newly-created one.)

[As an aside: I've got an idea, Google! Why don't you refer to versions of Android-Studio using numbers like 0.1.9 and 0.2.0, but then when users click on 'About' menu item, or search elsewhere for what version they are running, you could baffle them with crap like 'the July 11th build' or aka, some build number with 6 or 8 digits of numbering, and make them wonder what version they actually have! That will keep the developers guessing...really will sort the wheat from the chaff, etc.]

For example, I originally installed a kit named: android-studio-bundle-130.687321-windows.exe

Today, I got the "0.2.0" kit???, and it has a name like: android-studio-bundle-130.737825-windows.exe

Yep, this version #ing system is about as clear as mud.
Why bother with the illusion of version#s, when you don't use them!!!???

Requery a subform from another form?

I had a similar kind of issue, but with some differences...

In my case, my main form has a Control (vendor) which value I used to update a Query in my DB, using the following code:

Sub Set_Qry_PedidosRealizadosImportados_frm(Vd As Long)
Dim temp_qry As DAO.QueryDef

'Procedimento para ajustar o codigo do cliente na Qry_Pedidos realizados e importados
'Procedure to adjust the code of the client on Qry_Pedidos realizados e importados
Set temp_qry = CurrentDb.QueryDefs("Qry_Pedidos realizados e importados")
temp_qry.SQL = "SELECT DISTINCT " & _
            "[Qry_Pedidos distintos].[Codigo], " & _
            "[Qry_Pedidos distintos].[Razao social], " & _
            "COUNT([Qry_Pedidos distintos].[Pedido Avante]) As [Pedidos realizados], " & _
            "SUM(IIf(NZ([Qry_Pedidos distintos].[Pedido Flexx], 0) > 1, 1, 0)) As [Pedidos Importados] " & _
            "FROM [Qry_Pedidos distintos] " & _
            "WHERE [Qry_Pedidos distintos].Vd = " & Vd & _
            " Group BY " & _
            "[Qry_Pedidos distintos].[Razao social], " & _
            "[Qry_Pedidos distintos].[Codigo];"
End Sub

Since the beginning my subform record source was the query named "Qry_Pedidos realizados e importados".

But the only way I could update the subform data inside the main form context was to refresh the data source of the subform to it self, like posted bellow:

Private Sub cmb_vendedor_v1_Exit(Cancel As Integer)
'Codigo para atualizar o comando SQL da query
'Code to update the SQL statement of the query 
    Call Set_Qry_Pedidosrealizadosimportados_frm(Me.cmb_vendedor_v1.Value)

'Codigo para forçar o Access a aceitar o novo comando SQL
'Code to force de Access to accept the new sql statement
    Me!Frm_Pedidos_realizados_importados.Form.RecordSource = "Qry_Pedidos realizados e importados"
End Sub

No refresh, recalc, requery, etc, was necessary after all...

Warning comparison between pointer and integer

In this line ...

if (*message == "\0") {

... as you can see in the warning ...

warning: comparison between pointer and integer
      ('int' and 'char *')

... you are actually comparing an int with a char *, or more specifically, an int with an address to a char.

To fix this, use one of the following:

if(*message == '\0') ...
if(message[0] == '\0') ...
if(!*message) ...

On a side note, if you'd like to compare strings you should use strcmp or strncmp, found in string.h.

Comparing arrays for equality in C++

You are comparing the addresses instead of the values.

ExecutorService, how to wait for all tasks to finish

Sounds like you need ForkJoinPool and use the global pool to execute tasks.

public static void main(String[] args) {
    // the default `commonPool` should be sufficient for many cases.
    ForkJoinPool pool = ForkJoinPool.commonPool(); 
    // The root of your task that may spawn other tasks. 
    // Make sure it submits the additional tasks to the same executor that it is in.
    Runnable rootTask = new YourTask(pool); 
    pool.execute(rootTask);
    pool.awaitQuiescence(...);
    // that's it.
}

The beauty is in pool.awaitQuiescence where the method will block utilize the caller's thread to execute its tasks and then return when it is really empty.

Error - Android resource linking failed (AAPT2 27.0.3 Daemon #0)

Try update latest build version, target and compile version and also update dependencies but not works for me

In my case change <meta-items/> to <meta-data/> in manifest works for me...

Hope its helpful for someone...

java.lang.NoClassDefFoundError: org/json/JSONObject

The Exception it self says it all java.lang.ClassNotFoundException: org.json.JSONObject

You have not added the necessary jar file which will be having org.json.JSONObject class to your classpath.

You can Download it From Here

Perl read line by line

#!/usr/bin/perl
use utf8                       ;
use 5.10.1                     ;
use strict                     ;
use autodie                    ;
use warnings FATAL => q  ?all?;
binmode STDOUT     => q ?:utf8?;                  END {
close   STDOUT                 ;                     }
our    $FOLIO      =  q + SnPmaster.txt +            ;
open    FOLIO                  ;                 END {
close   FOLIO                  ;                     }
binmode FOLIO      => q{       :crlf
                               :encoding(CP-1252)    };
while (<FOLIO>)  { print       ;                     }
       continue  { ${.} ^015^  __LINE__  ||   exit   }
                                                                                                                                                                                                                                              __END__
unlink  $FOLIO                 ;
unlink ~$HOME ||
  clri ~$HOME                  ;
reboot                         ;

Angular 2 beta.17: Property 'map' does not exist on type 'Observable<Response>'

property 'map' does not exist on type 'observable response ' angular 6

Solution: Update Angular CLI And Core Version

ng update @angular/cli           //Update Angular CLi 
ng update @angular/core          //Update Angular Core 
npm install --save rxjs-compat   //For Map Call For Post Method 

Phone Number Validation MVC

Along with the above answers Try this for min and max length:

In Model

[StringLength(13, MinimumLength=10)]
public string MobileNo { get; set; }

In view

 <div class="col-md-8">
           @Html.TextBoxFor(m => m.MobileNo, new { @class = "form-control" , type="phone"})
           @Html.ValidationMessageFor(m => m.MobileNo,"Invalid Number")
           @Html.CheckBoxFor(m => m.IsAgreeTerms, new {@checked="checked",style="display:none" })
  </div>

Oracle: is there a tool to trace queries, like Profiler for sql server?

Oracle, along with other databases, analyzes a given query to create an execution plan. This plan is the most efficient way of retrieving the data.

Oracle provides the 'explain plan' statement which analyzes the query but doesn't run it, instead populating a special table that you can query (the plan table).

The syntax (simple version, there are other options such as to mark the rows in the plan table with a special ID, or use a different plan table) is:

explain plan for <sql query>

The analysis of that data is left for another question, or your further research.

How to make a simple collection view with Swift

For swift 4.2 --

//MARK: UICollectionViewDataSource

func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
    return 1     //return number of sections in collection view
}

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 10    //return number of rows in section
}

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "collectionCell", for: indexPath as IndexPath)
    configureCell(cell: cell, forItemAtIndexPath: indexPath)
    return cell      //return your cell
}

func configureCell(cell: UICollectionViewCell, forItemAtIndexPath: NSIndexPath) {
    cell.backgroundColor = UIColor.black


    //Customise your cell

}

func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
    let view =  collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "collectionCell", for: indexPath as IndexPath) as UICollectionReusableView
    return view
}

//MARK: UICollectionViewDelegate
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    // When user selects the cell
}

func collectionView(collectionView: UICollectionView, didDeselectItemAtIndexPath indexPath: NSIndexPath) {
    // When user deselects the cell
}

How do I center text vertically and horizontally in Flutter?

Text alignment center property setting only horizontal alignment.

enter image description here

I used below code to set text vertically and horizontally center.

enter image description here

Code:

      child: Center(
        child: Text(
          "Hello World",
          textAlign: TextAlign.center,
        ),
      ),

How do I format date and time on ssrs report?

The following is how I do it using Visual Studio 2017 for an RDL targetted for SSRS 2017:

Right-click on the field in the textbox on the design surface and choose Placeholder Properties. Choose the Number panel and click on Date in the Category listbox, then select the formatting you are looking for in the Type listbox.

How can I close a login form and show the main form without my application closing?

public void ShowMain()
  {
       if(auth()) // a method that returns true when the user exists.
       {        
         this.Hide();
         var main = new Main();
         main.Show();
       }
      else
       {
              MessageBox.Show("Invalid login details.");
        }         
   }

Check if all checkboxes are selected

$('input.abc').not(':checked').length > 0

jQuery - find table row containing table cell containing specific text

I know this is an old post but I thought I could share an alternative [not as robust, but simpler] approach to searching for a string in a table.

$("tr:contains(needle)"); //where needle is the text you are searching for.

For example, if you are searching for the text 'box', that would be:

$("tr:contains('box')");

This would return all the elements with this text. Additional criteria could be used to narrow it down if it returns multiple elements

How to urlencode data for curl command?

Use Perl's URI::Escape module and uri_escape function in the second line of your bash script:

...

value="$(perl -MURI::Escape -e 'print uri_escape($ARGV[0]);' "$2")"
...

Edit: Fix quoting problems, as suggested by Chris Johnsen in the comments. Thanks!

Is there a way to create multiline comments in Python?

I think it doesn't, except that a multiline string isn't processed. However, most, if not all Python IDEs have a shortkey for 'commenting out' multiple lines of code.

assembly to compare two numbers

input password program
.modle small
.stack 100h
.data
s pasword db 34
input pasword db "enter pasword","$"
valid db ?
invalid db?
.code
mov ax, @ data 
mov db, ax
mov ah,09h
mov dx, offest s pasword
int 21h
mov ah, 01h
cmp al, s pasword
je v
jmp nv
v:
mov ah, 09h
mov dx, offset valid 
int 21h
nv:
mov ah, 09h
mov dx, offset invalid 
int 21h
mov ah, 04ch 
int 21
end 

Printf width specifier to maintain precision of floating-point value

I recommend @Jens Gustedt hexadecimal solution: use %a.

OP wants “print with maximum precision (or at least to the most significant decimal)”.

A simple example would be to print one seventh as in:

#include <float.h>
int Digs = DECIMAL_DIG;
double OneSeventh = 1.0/7.0;
printf("%.*e\n", Digs, OneSeventh);
// 1.428571428571428492127e-01

But let's dig deeper ...

Mathematically, the answer is "0.142857 142857 142857 ...", but we are using finite precision floating point numbers. Let's assume IEEE 754 double-precision binary. So the OneSeventh = 1.0/7.0 results in the value below. Also shown are the preceding and following representable double floating point numbers.

OneSeventh before = 0.1428571428571428 214571170656199683435261249542236328125
OneSeventh        = 0.1428571428571428 49212692681248881854116916656494140625
OneSeventh after  = 0.1428571428571428 769682682968777953647077083587646484375

Printing the exact decimal representation of a double has limited uses.

C has 2 families of macros in <float.h> to help us.
The first set is the number of significant digits to print in a string in decimal so when scanning the string back, we get the original floating point. There are shown with the C spec's minimum value and a sample C11 compiler.

FLT_DECIMAL_DIG   6,  9 (float)                           (C11)
DBL_DECIMAL_DIG  10, 17 (double)                          (C11)
LDBL_DECIMAL_DIG 10, 21 (long double)                     (C11)
DECIMAL_DIG      10, 21 (widest supported floating type)  (C99)

The second set is the number of significant digits a string may be scanned into a floating point and then the FP printed, still retaining the same string presentation. There are shown with the C spec's minimum value and a sample C11 compiler. I believe available pre-C99.

FLT_DIG   6, 6 (float)
DBL_DIG  10, 15 (double)
LDBL_DIG 10, 18 (long double)

The first set of macros seems to meet OP's goal of significant digits. But that macro is not always available.

#ifdef DBL_DECIMAL_DIG
  #define OP_DBL_Digs (DBL_DECIMAL_DIG)
#else  
  #ifdef DECIMAL_DIG
    #define OP_DBL_Digs (DECIMAL_DIG)
  #else  
    #define OP_DBL_Digs (DBL_DIG + 3)
  #endif
#endif

The "+ 3" was the crux of my previous answer. Its centered on if knowing the round-trip conversion string-FP-string (set #2 macros available C89), how would one determine the digits for FP-string-FP (set #1 macros available post C89)? In general, add 3 was the result.

Now how many significant digits to print is known and driven via <float.h>.

To print N significant decimal digits one may use various formats.

With "%e", the precision field is the number of digits after the lead digit and decimal point. So - 1 is in order. Note: This -1 is not in the initial int Digs = DECIMAL_DIG;

printf("%.*e\n", OP_DBL_Digs - 1, OneSeventh);
// 1.4285714285714285e-01

With "%f", the precision field is the number of digits after the decimal point. For a number like OneSeventh/1000000.0, one would need OP_DBL_Digs + 6 to see all the significant digits.

printf("%.*f\n", OP_DBL_Digs    , OneSeventh);
// 0.14285714285714285
printf("%.*f\n", OP_DBL_Digs + 6, OneSeventh/1000000.0);
// 0.00000014285714285714285

Note: Many are use to "%f". That displays 6 digits after the decimal point; 6 is the display default, not the precision of the number.

MySQL show current connection info

If you want to know the port number of your local host on which Mysql is running you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'port';


mysql> SHOW VARIABLES WHERE Variable_name = 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.00 sec)

It will give you the port number on which MySQL is running.


If you want to know the hostname of your Mysql you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'hostname';


mysql> SHOW VARIABLES WHERE Variable_name = 'hostname';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| hostname          | Dell  |
+-------------------+-------+
1 row in set (0.00 sec)

It will give you the hostname for mysql.


If you want to know the username of your Mysql you can use this query on MySQL Command line client --

select user();   


mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

It will give you the username for mysql.

no debugging symbols found when using gdb

You should also try -ggdb instead of -g if you're compiling for Android!

Go to next item in ForEach-Object

I know this is an old post, but I wanted to add something I learned for the next folks who land here while googling.

In Powershell 5.1, you want to use continue to move onto the next item in your loop. I tested with 6 items in an array, had a foreach loop through, but put an if statement with:

foreach($i in $array){    
    write-host -fore green "hello $i"
    if($i -like "something"){
        write-host -fore red "$i is bad"
        continue
        write-host -fore red "should not see this"
    }
}

Of the 6 items, the 3rd one was something. As expected, it looped through the first 2, then the matching something gave me the red line where $i matched, I saw something is bad and then it went on to the next item in the array without saying should not see this. I tested with return and it exited the loop altogether.

Creating a recursive method for Palindrome

public class chkPalindrome{

public static String isPalindrome(String pal){

if(pal.length() == 1){

return pal;
}
else{

String tmp= "";

tmp = tmp + pal.charAt(pal.length()-1)+isPalindrome(pal.substring(0,pal.length()-1));

return tmp;
}


}
     public static void main(String []args){

         chkPalindrome hwObj = new chkPalindrome();
         String palind = "MADAM";

       String retVal= hwObj.isPalindrome(palind);
      if(retVal.equals(palind))
       System.out.println(palind+" is Palindrome");
       else
       System.out.println(palind+" is Not Palindrome");
     }
}

Fitting a histogram with python

Here is an example that uses scipy.optimize to fit a non-linear functions like a Gaussian, even when the data is in a histogram that isn't well ranged, so that a simple mean estimate would fail. An offset constant also would cause simple normal statistics to fail ( just remove p[3] and c[3] for plain gaussian data).

from pylab import *
from numpy import loadtxt
from scipy.optimize import leastsq

fitfunc  = lambda p, x: p[0]*exp(-0.5*((x-p[1])/p[2])**2)+p[3]
errfunc  = lambda p, x, y: (y - fitfunc(p, x))

filename = "gaussdata.csv"
data     = loadtxt(filename,skiprows=1,delimiter=',')
xdata    = data[:,0]
ydata    = data[:,1]

init  = [1.0, 0.5, 0.5, 0.5]

out   = leastsq( errfunc, init, args=(xdata, ydata))
c = out[0]

print "A exp[-0.5((x-mu)/sigma)^2] + k "
print "Parent Coefficients:"
print "1.000, 0.200, 0.300, 0.625"
print "Fit Coefficients:"
print c[0],c[1],abs(c[2]),c[3]

plot(xdata, fitfunc(c, xdata))
plot(xdata, ydata)

title(r'$A = %.3f\  \mu = %.3f\  \sigma = %.3f\ k = %.3f $' %(c[0],c[1],abs(c[2]),c[3]));

show()

Output:

A exp[-0.5((x-mu)/sigma)^2] + k 
Parent Coefficients:
1.000, 0.200, 0.300, 0.625
Fit Coefficients:
0.961231625289 0.197254597618 0.293989275502 0.65370344131

gaussian plot with fit

How does the ARM architecture differ from x86?

Additional to Jerry Coffin's first paragraph. Ie, ARM design gives lower power consumption.

The company ARM, only licenses the CPU technology. They don't make physical chips. This allows other companies to add various peripheral technologies, typically called SOC or system-on-chip. Whether the device is a tablet, a cell phone, or an in-car entertainment system. This allows chip vendors to tailor the rest of the chip to a particular application. This has additional benefits,

  1. Lower board cost
  2. Lower power (note1)
  3. Easier manufacture
  4. Smaller form factor

ARM supports SOC vendors with AMBA, allowing SOC implementers to purchase off the shelf 3rd party modules; like an Ethernet, memory and interrupt controllers. Some other CPU platforms support this, like MIPS, but MIPS is not as power conscious.

All of these are beneficial to a handheld/battery operated design. Some are just good all around. As well, ARM has a history of battery operated devices; Apple Newton, Psion Organizers. The PDA software infra-structure was leveraged by some companies to create smart phone type devices. Although, more success was had by those who re-invented the GUI for use with a smart phone.

The rise of Open source tool sets and operating systems also facilitated the various SOC chips. A closed organization would have issues trying to support all the various devices available for the ARM. The two most popular cellular platforms, Andriod and OSx/IOS, are based up Linux and FreeBSD, Mach and NetBSD os's. Open Source helps SOC vendors provide software support for their chip sets.

Hopefully, why x86 is used for the keyboard is self-evident. It has the software, and more importantly people trained to use that software. Netwinder is one ARM system that was originally designed for the keyboard. Also, manufacturer's are currently looking at ARM64 for the server market. Power/heat is a concern at 24/7 data centers.

So I would say that the ecosystem that grows around these chips is as important as features like low power consumption. ARM has been striving for low power, higher performance computing for some time (mid to late 1980's) and they have a lot of people on board.

Note1: Multiple chips need bus drivers to inter-communicate at known voltages and drive. Also, typically separate chips need support capacitors and other power components which can be shared in an SOC system.

IE8 crashes when loading website - res://ieframe.dll/acr_error.htm

To prevent IE8 from going on an endless loop of refreshing and crashing it stops after two times and shows this url. There could be many issues that might be causing it to crash.

In my case an upgrade to jQuery v1.10.2 from v1.4.4 causing the issue, but it must have been mostly our code bad and was now more evident with the upgrade.

My observation was everything seems working fine on IE7/XP, IE8/Win7, IE9/Win7 and IE10/Win7 but was not working fine on IE8/XP and IE8/Server2003. The version of IE8 on Win7 and XP/Server 2003 are different. Here is the list of versions for each Operating System (http://support.microsoft.com/kb/969393).

Then looked at Event viewer on Win Server 2003 and it had something like faulting module mshtml.dll, version 8.0.6001.18975 and on Win XP it was faulting module mshtml.dll, version 8.0.6001.18702 even though the browser version is same on both which is 8.0.6001.18702.

Then further searching about this mshtml.dll, it looks like Microsoft keeps updating mshtml.dll which is the HTML component of the browser through patches. So then I realised its not the browser version that is important but mshtml.dll version instead.

So I went ahead and downloaded the latest Cumulative patch for IE8 from here (https://technet.microsoft.com/en-us/security/bulletin/ms13-059) which updated my mshtml.dll file (in system32 folder) to 8.0.6001.23515 and it started working fine , may be they fixed it some time back probably in this (http://technet.microsoft.com/en-us/security/bulletin/ms12-037)

See also:

http://support.microsoft.com/kb/980344 http://support.microsoft.com/kb/979665

But first things first always reset your browser so that you disable all plugins and rule out the possible cause by external plugins.

Can't draw Histogram, 'x' must be numeric

Use the dec argument to set "," as the decimal point by adding:

 ce <- read.table("file.txt", header = TRUE, dec = ",")

Read a file in Node.js

To read the html file from server using http module. This is one way to read file from server. If you want to get it on console just remove http module declaration.

_x000D_
_x000D_
var http = require('http');_x000D_
var fs = require('fs');_x000D_
var server = http.createServer(function(req, res) {_x000D_
  fs.readFile('HTMLPage1.html', function(err, data) {_x000D_
    if (!err) {_x000D_
      res.writeHead(200, {_x000D_
        'Content-Type': 'text/html'_x000D_
      });_x000D_
      res.write(data);_x000D_
      res.end();_x000D_
    } else {_x000D_
      console.log('error');_x000D_
    }_x000D_
  });_x000D_
});_x000D_
server.listen(8000, function(req, res) {_x000D_
  console.log('server listening to localhost 8000');_x000D_
});
_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
  <h1>My Header</h1>_x000D_
  <p>My paragraph.</p>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

IllegalStateException: Can not perform this action after onSaveInstanceState with ViewPager

Fragment transactions should not be executed after Activity.onStop() ! Check that you do not have any callbacks that could execute transaction after onStop(). It is better to fix the reason instead of trying to walk around the problem with approaches like .commitAllowingStateLoss()

JQuery datepicker language

In 2020, just do

$.datetimepicker.setLocale('en');

Of course, replace 'en' with the correct language ('sv', 'fr', ...)

How to parse json string in Android?

Use JSON classes for parsing e.g

JSONObject mainObject = new JSONObject(Your_Sring_data);
JSONObject uniObject = mainObject.getJSONObject("university");
String  uniName = uniObject.getString("name");
String uniURL = uniObject.getString("url");

JSONObject oneObject = mainObject.getJSONObject("1");
String id = oneObject.getString("id");
....

Normalize data in pandas

If you don't mind importing the sklearn library, I would recommend the method talked on this blog.

import pandas as pd
from sklearn import preprocessing

data = {'score': [234,24,14,27,-74,46,73,-18,59,160]}
cols = data.columns
df = pd.DataFrame(data)
df

min_max_scaler = preprocessing.MinMaxScaler()
np_scaled = min_max_scaler.fit_transform(df)
df_normalized = pd.DataFrame(np_scaled, columns = cols)
df_normalized

git stash -> merge stashed change with current changes

May be, it is not the very worst idea to merge (via difftool) from ... yes ... a branch!

> current_branch=$(git status | head -n1 | cut -d' ' -f3)
> stash_branch="$current_branch-stash-$(date +%yy%mm%dd-%Hh%M)"
> git stash branch $stash_branch
> git checkout $current_branch
> git difftool $stash_branch

How to jump to top of browser page

You could do it without javascript and simply use anchor tags? Then it would be accessible to those js free.

although as you are using modals, I assume you don't care about being js free. ;)

How to set cellpadding and cellspacing in table with CSS?

Use padding on the cells and border-spacing on the table. The former will give you cellpadding while the latter will give you cellspacing.

table { border-spacing: 5px; } /* cellspacing */

th, td { padding: 5px; } /* cellpadding */

jsFiddle Demo

How to get next/previous record in MySQL?

Using @Dan 's approach, you can create JOINs. Just use a different @variable for each sub query.

SELECT current_row.row, current_row.id, previous_row.row, previous_row.id
FROM (
  SELECT @rownum:=@rownum+1 row, a.* 
  FROM articles a, (SELECT @rownum:=0) r
  ORDER BY date, id
) as current_row
LEFT JOIN (
  SELECT @rownum2:=@rownum2+1 row, a.* 
  FROM articles a, (SELECT @rownum2:=0) r
  ORDER BY date, id
) as previous_row ON
  (current_row.id = previous_row.id) AND (current_row.row = previous_row.row - 1)

Maven : error in opening zip file when running maven

This issue is a pain in my a$$, I have this issue in my Mac, if I run

mvn clean install | grep "error reading"
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/velocity/velocity/1.7/velocity-1.7.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/commons-net/commons-net/3.3/commons-net-3.3.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/commons/commons-lang3/3.0/commons-lang3-3.0.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.54/bcprov-jdk15on-1.54.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/javax/mail/mail/1.4/mail-1.4.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/pdfbox/pdfbox/2.0.0/pdfbox-2.0.0.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/com/itextpdf/itextpdf/5.5.10/itextpdf-5.5.10.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/slf4j/slf4j-api/1.7.24/slf4j-api-1.7.24.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/com/aspose/aspose-pdf/11.5.0/aspose-pdf-11.5.0.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/velocity/velocity/1.7/velocity-1.7.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/commons-net/commons-net/3.3/commons-net-3.3.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/commons/commons-lang3/3.0/commons-lang3-3.0.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/bouncycastle/bcprov-jdk15on/1.54/bcprov-jdk15on-1.54.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/javax/mail/mail/1.4/mail-1.4.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/apache/pdfbox/pdfbox/2.0.0/pdfbox-2.0.0.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/com/itextpdf/itextpdf/5.5.10/itextpdf-5.5.10.jar; error in opening zip file
[ERROR] error reading /Users/ducnguyen/.m2/repository/org/slf4j/slf4j-api/1.7.24/slf4j-api-1.7.24.jar; error in opening zip file

Removing all corrupted libs is the only solution

So I want to remove all of them at once.

mvn clean install | grep "error reading" | awk '{print "rm " $4 | "/bin/sh"  }'

The command needs AWK to take libPath string from column $4

Then rerun

mvn clean install

AngularJs ReferenceError: $http is not defined

I have gone through the same problem when I was using

    myApp.controller('mainController', ['$scope', function($scope,) {
        //$http was not working in this
    }]);

I have changed the above code to given below. Remember to include $http(2 times) as given below.

 myApp.controller('mainController', ['$scope','$http', function($scope,$http) {
      //$http is working in this
 }]);

and It has worked well.

Get only the Date part of DateTime in mssql

This may also help:

SELECT convert(varchar, getdate(), 100) -- mon dd yyyy hh:mmAM (or PM)
                                        -- Oct  2 2008 11:01AM
SELECT convert(varchar, getdate(), 101) -- mm/dd/yyyy - 10/02/2008                  
SELECT convert(varchar, getdate(), 102) -- yyyy.mm.dd – 2008.10.02           
SELECT convert(varchar, getdate(), 103) -- dd/mm/yyyy
SELECT convert(varchar, getdate(), 104) -- dd.mm.yyyy
SELECT convert(varchar, getdate(), 105) -- dd-mm-yyyy
SELECT convert(varchar, getdate(), 106) -- dd mon yyyy
SELECT convert(varchar, getdate(), 107) -- mon dd, yyyy
SELECT convert(varchar, getdate(), 108) --  hh:mm:ss
SELECT convert(varchar, getdate(), 109) -- mon dd yyyy hh:mm:ss:mmmAM (or PM)
                                        -- Oct  2 2008 11:02:44:013AM   
SELECT convert(varchar, getdate(), 110) -- mm-dd-yyyy
SELECT convert(varchar, getdate(), 111) -- yyyy/mm/dd
SELECT convert(varchar, getdate(), 112) -- yyyymmdd
SELECT convert(varchar, getdate(), 113) -- dd mon yyyy hh:mm:ss:mmm
                                        --  02 Oct 2008 11:02:07:577     
SELECT convert(varchar, getdate(), 114) -- hh:mm:ss:mmm(24h)
SELECT convert(varchar, getdate(), 120) -- yyyy-mm-dd hh:mm:ss(24h)
SELECT convert(varchar, getdate(), 121) --  yyyy-mm-dd hh:mm:ss.mmm
SELECT convert(varchar, getdate(), 126) -- yyyy-mm-ddThh:mm:ss.mmm
                                        --  2008-10-02T10:52:47.513
-- SQL create different date styles with t-sql string functions
SELECT replace(convert(varchar, getdate(), 111), '/', ' ') -- yyyy mm dd
SELECT convert(varchar(7), getdate(), 126)                 -- yyyy-mm
SELECT right(convert(varchar, getdate(), 106), 8)          -- mon yyyy

The Source

matplotlib colorbar in each subplot

Please have a look at this matplotlib example page. There it is shown how to get the following plot with four individual colorbars for each subplot: enter image description here

I hope this helps.
You can further have a look here, where you can find a lot of what you can do with matplotlib.

How to split data into trainset and testset randomly?

This can be done similarly in Python using lists, (note that the whole list is shuffled in place).

import random

with open("datafile.txt", "rb") as f:
    data = f.read().split('\n')

random.shuffle(data)

train_data = data[:50]
test_data = data[50:]

Pandas KeyError: value not in index

please try this to clean and format your column names:

df.columns = (df.columns.str.strip().str.upper()
              .str.replace(' ', '_')
              .str.replace('(', '')
              .str.replace(')', ''))

Export DataBase with MySQL Workbench with INSERT statements

If you want to export just single table, or subset of data from some table, you can do it directly from result window:

  1. Click export button: enter image description here

  2. Change Save as type to "SQL Insert statements" enter image description here

How does the enhanced for statement work for arrays, and how to get an iterator for an array?

Strictly speaking, you can't get an iterator of the primitive array, because Iterator.next() can only return an Object. But through the magic of autoboxing, you can get the iterator using the Arrays.asList() method.

Iterator<Integer> it = Arrays.asList(arr).iterator();

The above answer is wrong, you can't use Arrays.asList() on a primitive array, it would return a List<int[]>. Use Guava's Ints.asList() instead.

Importing csv file into R - numeric values read as characters

Whatever algebra you are doing in Excel to create the new column could probably be done more effectively in R.

Please try the following: Read the raw file (before any excel manipulation) into R using read.csv(... stringsAsFactors=FALSE). [If that does not work, please take a look at ?read.table (which read.csv wraps), however there may be some other underlying issue].

For example:

   delim = ","  # or is it "\t" ?
   dec = "."    # or is it "," ?
   myDataFrame <- read.csv("path/to/file.csv", header=TRUE, sep=delim, dec=dec, stringsAsFactors=FALSE)

Then, let's say your numeric columns is column 4

   myDataFrame[, 4]  <- as.numeric(myDataFrame[, 4])  # you can also refer to the column by "itsName"


Lastly, if you need any help with accomplishing in R the same tasks that you've done in Excel, there are plenty of folks here who would be happy to help you out

CSS Flex Box Layout: full-width row and columns

You've almost done it. However setting flex: 0 0 <basis> declaration to the columns would prevent them from growing/shrinking; And the <basis> parameter would define the width of columns.

In addition, you could use CSS3 calc() expression to specify the height of columns with the respect to the height of the header.

#productShowcaseTitle {
  flex: 0 0 100%; /* Let it fill the entire space horizontally */
  height: 100px;
}

#productShowcaseDetail,
#productShowcaseThumbnailContainer {
  height: calc(100% - 100px); /* excluding the height of the header */
}

_x000D_
_x000D_
#productShowcaseContainer {_x000D_
  display: flex;_x000D_
  flex-flow: row wrap;_x000D_
_x000D_
  height: 600px;_x000D_
  width: 580px;_x000D_
}_x000D_
_x000D_
#productShowcaseTitle {_x000D_
  flex: 0 0 100%; /* Let it fill the entire space horizontally */_x000D_
  height: 100px;_x000D_
  background-color: silver;_x000D_
}_x000D_
_x000D_
#productShowcaseDetail {_x000D_
  flex: 0 0 66%; /* ~ 2 * 33.33% */_x000D_
  height: calc(100% - 100px); /* excluding the height of the header */_x000D_
  background-color: lightgray;_x000D_
}_x000D_
_x000D_
#productShowcaseThumbnailContainer {_x000D_
  flex: 0 0 34%;  /* ~ 33.33% */_x000D_
  height: calc(100% - 100px); /* excluding the height of the header */_x000D_
  background-color: black;_x000D_
}
_x000D_
<div id="productShowcaseContainer">_x000D_
  <div id="productShowcaseTitle"></div>_x000D_
  <div id="productShowcaseDetail"></div>_x000D_
  <div id="productShowcaseThumbnailContainer"></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

(Vendor prefixes omitted due to brevity)


Alternatively, if you could change your markup e.g. wrapping the columns by an additional <div> element, it would be achieved without using calc() as follows:

<div class="contentContainer"> <!-- Added wrapper -->
    <div id="productShowcaseDetail"></div>
    <div id="productShowcaseThumbnailContainer"></div>
</div>
#productShowcaseContainer {
  display: flex;
  flex-direction: column;
  height: 600px; width: 580px;
}

.contentContainer { display: flex; flex: 1; }
#productShowcaseDetail { flex: 3; }
#productShowcaseThumbnailContainer { flex: 2; }

_x000D_
_x000D_
#productShowcaseContainer {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
_x000D_
  height: 600px;_x000D_
  width: 580px;_x000D_
}_x000D_
_x000D_
.contentContainer {_x000D_
  display: flex;_x000D_
  flex: 1;_x000D_
}_x000D_
_x000D_
#productShowcaseTitle {_x000D_
  height: 100px;_x000D_
  background-color: silver;_x000D_
}_x000D_
_x000D_
#productShowcaseDetail {_x000D_
  flex: 3;_x000D_
  background-color: lightgray;_x000D_
}_x000D_
_x000D_
#productShowcaseThumbnailContainer {_x000D_
  flex: 2;_x000D_
  background-color: black;_x000D_
}
_x000D_
<div id="productShowcaseContainer">_x000D_
  <div id="productShowcaseTitle"></div>_x000D_
_x000D_
  <div class="contentContainer"> <!-- Added wrapper -->_x000D_
    <div id="productShowcaseDetail"></div>_x000D_
    <div id="productShowcaseThumbnailContainer"></div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

(Vendor prefixes omitted due to brevity)

Changing button color programmatically

I believe you want bgcolor. Something like this:

document.getElementById("button").bgcolor="#ffffff";

Here are a couple of demos that might help:

Background Color

Background Color Changer

How to create jobs in SQL Server Express edition

SQL Server Express doesn't include SQL Server Agent, so it's not possible to just create SQL Agent jobs.

What you can do is:
You can create jobs "manually" by creating batch files and SQL script files, and running them via Windows Task Scheduler.
For example, you can backup your database with two files like this:

backup.bat:

sqlcmd -i backup.sql

backup.sql:

backup database TeamCity to disk = 'c:\backups\MyBackup.bak'

Just put both files into the same folder and exeute the batch file via Windows Task Scheduler.

The first file is just a Windows batch file which calls the sqlcmd utility and passes a SQL script file.
The SQL script file contains T-SQL. In my example, it's just one line to backup a database, but you can put any T-SQL inside. For example, you could do some UPDATE queries instead.


If the jobs you want to create are for backups, index maintenance or integrity checks, you could also use the excellent Maintenance Solution by Ola Hallengren.

It consists of a bunch of stored procedures (and SQL Agent jobs for non-Express editions of SQL Server), and in the FAQ there’s a section about how to run the jobs on SQL Server Express:

How do I get started with the SQL Server Maintenance Solution on SQL Server Express?

SQL Server Express has no SQL Server Agent. Therefore, the execution of the stored procedures must be scheduled by using cmd files and Windows Scheduled Tasks. Follow these steps.

SQL Server Express has no SQL Server Agent. Therefore, the execution of the stored procedures must be scheduled by using cmd files and Windows Scheduled Tasks. Follow these steps.

  1. Download MaintenanceSolution.sql.

  2. Execute MaintenanceSolution.sql. This script creates the stored procedures that you need.

  3. Create cmd files to execute the stored procedures; for example:
    sqlcmd -E -S .\SQLEXPRESS -d master -Q "EXECUTE dbo.DatabaseBackup @Databases = 'USER_DATABASES', @Directory = N'C:\Backup', @BackupType = 'FULL'" -b -o C:\Log\DatabaseBackup.txt

  4. In Windows Scheduled Tasks, create tasks to call the cmd files.

  5. Schedule the tasks.

  6. Start the tasks and verify that they are completing successfully.

Add a month to a Date

Function %m+% from lubridate adds one month without exceeding last day of the new month.

library(lubridate)
(d <- ymd("2012-01-31"))
 1 parsed with %Y-%m-%d
[1] "2012-01-31 UTC"
d %m+% months(1)
[1] "2012-02-29 UTC"

How do you run a .bat file from PHP?

<?php
exec('c:\WINDOWS\system32\cmd.exe /c START C:\Program Files\VideoLAN\VLC\vlc.bat');
?>

Where can I find jenkins restful api reference?

Jenkins has a link to their REST API in the bottom right of each page. This link appears on every page of Jenkins and points you to an API output for the exact page you are browsing. That should provide some understanding into how to build the API URls.

You can additionally use some wrapper, like I do, in Python, using http://jenkinsapi.readthedocs.io/en/latest/

Here is their website: https://wiki.jenkins-ci.org/display/JENKINS/Remote+access+API

Lock, mutex, semaphore... what's the difference?

Take a look at Multithreading Tutorial by John Kopplin.

In the section Synchronization Between Threads, he explain the differences among event, lock, mutex, semaphore, waitable timer

A mutex can be owned by only one thread at a time, enabling threads to coordinate mutually exclusive access to a shared resource

Critical section objects provide synchronization similar to that provided by mutex objects, except that critical section objects can be used only by the threads of a single process

Another difference between a mutex and a critical section is that if the critical section object is currently owned by another thread, EnterCriticalSection() waits indefinitely for ownership whereas WaitForSingleObject(), which is used with a mutex, allows you to specify a timeout

A semaphore maintains a count between zero and some maximum value, limiting the number of threads that are simultaneously accessing a shared resource.

Efficient way to do batch INSERTS with JDBC

The Statement gives you the following option:

Statement stmt = con.createStatement();

stmt.addBatch("INSERT INTO employees VALUES (1000, 'Joe Jones')");
stmt.addBatch("INSERT INTO departments VALUES (260, 'Shoe')");
stmt.addBatch("INSERT INTO emp_dept VALUES (1000, 260)");

// submit a batch of update commands for execution
int[] updateCounts = stmt.executeBatch();

How to use radio buttons in ReactJS?

Bootstrap guys, we do it like this:


export default function RadioButton({ onChange, option }) {
    const handleChange = event => {
        onChange(event.target.value)
    }

    return (
        <>
            <div className="custom-control custom-radio">
                <input
                    type="radio"
                    id={ option.option }
                    name="customRadio"
                    className="custom-control-input"
                    onChange={ handleChange }
                    value = { option.id }
                    />
                    <label
                        className="custom-control-label"
                        htmlFor={ option.option }
                        >
                        { option.option }
                    </label>
            </div>
        </>
    )
}

Using tr to replace newline with space

Best guess is you are on windows and your line ending settings are set for windows. See this topic: How to change line-ending settings

or use:

tr '\r\n' ' '

Problems when trying to load a package in R due to rJava

If you have this issue with macOS, there is no easy way here: ( Especially, when you want to use R3.4. I have been there already.

R 3.4, rJava, macOS and even more mess

For R3.3 it's a little bit easier (R3.3 was compiled using different compiler).

R, Java, rJava and macOS adventures

Java: Check if command line arguments are null

The arguments can never be null. They just wont exist.

In other words, what you need to do is check the length of your arguments.

public static void main(String[] args)
{
    // Check how many arguments were passed in
    if(args.length == 0)
    {
        System.out.println("Proper Usage is: java program filename");
        System.exit(0);
    }
}

Refresh certain row of UITableView based on Int in Swift

SWIFT 4.2

    func reloadYourRows(name: <anyname>) {
    let row = <your array name>.index(of: <name passing in>)
    let reloadPath = IndexPath(row: row!, section: 0)
    tableView.reloadRows(at: [reloadPath], with: .middle)
    }

Unique random string generation

This works perfect for me

    private string GeneratePasswordResetToken()
    {
        string token = Guid.NewGuid().ToString();
        var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(token);
        return Convert.ToBase64String(plainTextBytes);
    }

How do you modify the web.config appSettings at runtime?

Changing the web.config generally causes an application restart.

If you really need your application to edit its own settings, then you should consider a different approach such as databasing the settings or creating an xml file with the editable settings.

"Port 4200 is already in use" when running the ng serve command

Only thing that works for me is to restart my system / device...

Using Webstorm IDE by JetBrains.

Formatting a double to two decimal places

I would recomment the Fixed-Point ("F") format specifier (as mentioned by Ehsan). See the Standard Numeric Format Strings.

With this option you can even have a configurable number of decimal places:

public string ValueAsString(double value, int decimalPlaces)
{
    return value.ToString($"F{decimalPlaces}");
}

Password encryption/decryption code in .NET

This question will answer how to encrypt/decrypt: Encrypt and decrypt a string in C#?

You didn't specify a database, but you will want to base-64 encode it, using Convert.toBase64String. For an example you can use: http://www.opinionatedgeek.com/Blog/blogentry=000361/BlogEntry.aspx

You'll then either save it in a varchar or a blob, depending on how long your encrypted message is, but for a password varchar should work.

The examples above will also cover decryption after decoding the base64.

UPDATE:

In actuality you may not need to use base64 encoding, but I found it helpful, in case I wanted to print it, or send it over the web. If the message is long enough it's best to compress it first, then encrypt, as it is harder to use brute-force when the message was already in a binary form, so it would be hard to tell when you successfully broke the encryption.

how to use List<WebElement> webdriver

List<WebElement> myElements = driver.findElements(By.xpath("some/path//a"));
        System.out.println("Size of List: "+myElements.size());
        for(WebElement e : myElements) 
        {        
            System.out.print("Text within the Anchor tab"+e.getText()+"\t");
            System.out.println("Anchor: "+e.getAttribute("href"));
        }

//NOTE: "//a" will give you all the anchors there on after the point your XPATH has reached.

python date of the previous month

There is a high level library dateparser that can determine the past date given natural language, and return the corresponding Python datetime object

from dateparser import parse
parse('4 months ago')

CSS overflow-x: visible; and overflow-y: hidden; causing scrollbar issue

I used the content+wrapper approach ... but I did something different than mentioned so far: I made sure that my wrapper's boundaries did NOT line up with the content's boundaries in the direction that I wanted to be visible.

Important NOTE: It was easy enough to get the content+wrapper, same-bounds approach to work on one browser or another depending on various css combinations of position, overflow-*, etc ... but I never could use that approach to get them all correct (Edge, Chrome, Safari, ...).

But when I had something like:

  <div id="hack_wrapper" // created solely for this purpose
       style="position:absolute; width:100%; height:100%; overflow-x:hidden;">
      <div id="content_wrapper"
           style="position:absolute; width:100%; height:15%; overflow:visible;">         
          ... content with too-much horizontal content ... 
      </div>
  </div>

... all browsers were happy.

What is the maximum length of a String in PHP?

To properly answer this qustion you need to consider PHP internals or the target that PHP is built for.

To answer this from a typical Linux perspective on x86...

Sizes of types in C: https://usrmisc.wordpress.com/2012/12/27/integer-sizes-in-c-on-32-bit-and-64-bit-linux/

Types used in PHP for variables: http://php.net/manual/en/internals2.variables.intro.php

Strings are always 2GB as the length is always 32bits and a bit is wasted because it uses int rather than uint. int is impractical for lengths over 2GB as it requires a cast to avoid breaking arithmetic or "than" comparisons. The extra bit is likely being used for overflow checks.

Strangely, hash keys might internally support 4GB as uint is used although I have never put this to the test. PHP hash keys have a +1 to the length for a trailing null byte which to my knowledge gets ignored so it may need to be unsigned for that edge case rather than to allow longer keys.

A 32bit system may impose more external limits.

Move view with keyboard using Swift

@Boris's solution is VERY good but the view can sometimes be corrupted.

For the perfect alignment, use the below code

override func viewDidLoad() {
super.viewDidLoad()            
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)}

Functions:

@objc func keyboardWillShow(notification: NSNotification) {        
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
    if self.view.frame.origin.y == 0{
        self.view.frame.origin.y -= keyboardSize.height
    }
}}    

And,

@objc func keyboardWillHide(notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
    if self.view.frame.origin.y != 0{
        self.view.frame.origin.y = 0 
    }
} }

scrollTop jquery, scrolling to div with id?

try this

    $('#div_id').animate({scrollTop:0}, '500', 'swing');

ReactJS - Does render get called any time "setState" is called?

Not All Components.

the state in component looks like the source of the waterfall of state of the whole APP.

So the change happens from where the setState called. The tree of renders then get called from there. If you've used pure component, the render will be skipped.

How to hide a TemplateField column in a GridView

GridView1.Columns[columnIndex].Visible = false;

How to include multiple js files using jQuery $.getScript() method

Use yepnope.js or Modernizr (which includes yepnope.js as Modernizr.load).

UPDATE

Just to follow up, here's a good equivalent of what you currently have using yepnope, showing dependencies on multiple scripts:

yepnope({
  load: ['script1.js', 'script2.js', 'script3.js'],
  complete: function () {
      // all the scripts have loaded, do whatever you want here
  }
});

How to reference image resources in XAML?

One of the benefit of using the resource file is accessing the resources by names, so the image can change, the image name can change, as long as the resource is kept up to date correct image will show up.

Here is a cleaner approach to accomplish this: Assuming Resources.resx is in 'UI.Images' namespace, add the namespace reference in your xaml like this:

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:UI="clr-namespace:UI.Images" 

Set your Image source like this:

<Image Source={Binding {x:Static UI:Resources.Search}} /> where 'Search' is name of the resource.

Why would we call cin.clear() and cin.ignore() after reading input?

The cin.clear() clears the error flag on cin (so that future I/O operations will work correctly), and then cin.ignore(10000, '\n') skips to the next newline (to ignore anything else on the same line as the non-number so that it does not cause another parse failure). It will only skip up to 10000 characters, so the code is assuming the user will not put in a very long, invalid line.

Automatic date update in a cell when another cell's value changes (as calculated by a formula)

You could fill the dependend cell (D2) by a User Defined Function (VBA Macro Function) that takes the value of the C2-Cell as input parameter, returning the current date as ouput.

Having C2 as input parameter for the UDF in D2 tells Excel that it needs to reevaluate D2 everytime C2 changes (that is if auto-calculation of formulas is turned on for the workbook).

EDIT:

Here is some code:

For the UDF:

    Public Function UDF_Date(ByVal data) As Date

        UDF_Date = Now()

    End Function

As Formula in D2:

=UDF_Date(C2)

You will have to give the D2-Cell a Date-Time Format, or it will show a numeric representation of the date-value.

And you can expand the formula over the desired range by draging it if you keep the C2 reference in the D2-formula relative.

Note: This still might not be the ideal solution because every time Excel recalculates the workbook the date in D2 will be reset to the current value. To make D2 only reflect the last time C2 was changed there would have to be some kind of tracking of the past value(s) of C2. This could for example be implemented in the UDF by providing also the address alonside the value of the input parameter, storing the input parameters in a hidden sheet, and comparing them with the previous values everytime the UDF gets called.

Addendum:

Here is a sample implementation of an UDF that tracks the changes of the cell values and returns the date-time when the last changes was detected. When using it, please be aware that:

  • The usage of the UDF is the same as described above.

  • The UDF works only for single cell input ranges.

  • The cell values are tracked by storing the last value of cell and the date-time when the change was detected in the document properties of the workbook. If the formula is used over large datasets the size of the file might increase considerably as for every cell that is tracked by the formula the storage requirements increase (last value of cell + date of last change.) Also, maybe Excel is not capable of handling very large amounts of document properties and the code might brake at a certain point.

  • If the name of a worksheet is changed all the tracking information of the therein contained cells is lost.

  • The code might brake for cell-values for which conversion to string is non-deterministic.

  • The code below is not tested and should be regarded only as proof of concept. Use it at your own risk.

    Public Function UDF_Date(ByVal inData As Range) As Date
    
        Dim wb As Workbook
        Dim dProps As DocumentProperties
        Dim pValue As DocumentProperty
        Dim pDate As DocumentProperty
        Dim sName As String
        Dim sNameDate As String
    
        Dim bDate As Boolean
        Dim bValue As Boolean
        Dim bChanged As Boolean
    
        bDate = True
        bValue = True
    
        bChanged = False
    
    
        Dim sVal As String
        Dim dDate As Date
    
        sName = inData.Address & "_" & inData.Worksheet.Name
        sNameDate = sName & "_dat"
    
        sVal = CStr(inData.Value)
        dDate = Now()
    
        Set wb = inData.Worksheet.Parent
    
        Set dProps = wb.CustomDocumentProperties
    
    On Error Resume Next
    
        Set pValue = dProps.Item(sName)
    
        If Err.Number <> 0 Then
            bValue = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bValue Then
            bChanged = True
            Set pValue = dProps.Add(sName, False, msoPropertyTypeString, sVal)
        Else
            bChanged = pValue.Value <> sVal
            If bChanged Then
                pValue.Value = sVal
            End If
        End If
    
    On Error Resume Next
    
        Set pDate = dProps.Item(sNameDate)
    
        If Err.Number <> 0 Then
            bDate = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bDate Then
            Set pDate = dProps.Add(sNameDate, False, msoPropertyTypeDate, dDate)
        End If
    
        If bChanged Then
            pDate.Value = dDate
        Else
            dDate = pDate.Value
        End If
    
    
        UDF_Date = dDate
     End Function
    

Make the insertion of the date conditional upon the range.

This has an advantage of not changing the dates unless the content of the cell is changed, and it is in the range C2:C2, even if the sheet is closed and saved, it doesn't recalculate unless the adjacent cell changes.

Adapted from this tip and @Paul S answer

Private Sub Worksheet_Change(ByVal Target As Range)
 Dim R1 As Range
 Dim R2 As Range
 Dim InRange As Boolean
    Set R1 = Range(Target.Address)
    Set R2 = Range("C2:C20")
    Set InterSectRange = Application.Intersect(R1, R2)

  InRange = Not InterSectRange Is Nothing
     Set InterSectRange = Nothing
   If InRange = True Then
     R1.Offset(0, 1).Value = Now()
   End If
     Set R1 = Nothing
     Set R2 = Nothing
 End Sub

twitter bootstrap autocomplete dropdown / combobox with Knockoutjs

Have a look at Select2 for Bootstrap. It should be able to do everything you need.

Another good option is Selectize.js. It feels a bit more native to Bootstrap.

Checking if type == list in python

You should try using isinstance()

if isinstance(object, list):
       ## DO what you want

In your case

if isinstance(tmpDict[key], list):
      ## DO SOMETHING

To elaborate:

x = [1,2,3]
if type(x) == list():
    print "This wont work"
if type(x) == list:                  ## one of the way to see if it's list
    print "this will work"           
if type(x) == type(list()):
    print "lets see if this works"
if isinstance(x, list):              ## most preferred way to check if it's list
    print "This should work just fine"

The difference between isinstance() and type() though both seems to do the same job is that isinstance() checks for subclasses in addition, while type() doesn’t.

How to mock private method for testing using PowerMock?

With no argument:

ourObject = PowerMockito.spy(new OurClass());
when(ourObject , "ourPrivateMethodName").thenReturn("mocked result");

With String argument:

ourObject = PowerMockito.spy(new OurClass());
when(ourObject, method(OurClass.class, "ourPrivateMethodName", String.class))
                .withArguments(anyString()).thenReturn("mocked result");

How do I set a cookie on HttpClient's HttpRequestMessage

Here's how you could set a custom cookie value for the request:

var baseAddress = new Uri("http://example.com");
var cookieContainer = new CookieContainer();
using (var handler = new HttpClientHandler() { CookieContainer = cookieContainer })
using (var client = new HttpClient(handler) { BaseAddress = baseAddress })
{
    var content = new FormUrlEncodedContent(new[]
    {
        new KeyValuePair<string, string>("foo", "bar"),
        new KeyValuePair<string, string>("baz", "bazinga"),
    });
    cookieContainer.Add(baseAddress, new Cookie("CookieName", "cookie_value"));
    var result = await client.PostAsync("/test", content);
    result.EnsureSuccessStatusCode();
}

Adding calculated column(s) to a dataframe in pandas

The first four functions you list will work on vectors as well, with the exception that lower_wick needs to be adapted. Something like this,

def lower_wick_vec(o, l, c):
    min_oc = numpy.where(o > c, c, o)
    return min_oc - l

where o, l and c are vectors. You could do it this way instead which just takes the df as input and avoid using numpy, although it will be much slower:

def lower_wick_df(df):
    min_oc = df[['Open', 'Close']].min(axis=1)
    return min_oc - l

The other three will work on columns or vectors just as they are. Then you can finish off with

def is_hammer(df):
    lw = lower_wick_at_least_twice_real_body(df["Open"], df["Low"], df["Close"]) 
    cl = closed_in_top_half_of_range(df["High"], df["Low"], df["Close"])
    return cl & lw

Bit operators can perform set logic on boolean vectors, & for and, | for or etc. This is enough to completely vectorize the sample calculations you gave and should be relatively fast. You could probably speed up even more by temporarily working with the numpy arrays underlying the data while performing these calculations.

For the second part, I would recommend introducing a column indicating the pattern for each row and writing a family of functions which deal with each pattern. Then groupby the pattern and apply the appropriate function to each group.

What do hjust and vjust do when making a plot using ggplot?

The value of hjust and vjust are only defined between 0 and 1:

  • 0 means left-justified
  • 1 means right-justified

Source: ggplot2, Hadley Wickham, page 196

(Yes, I know that in most cases you can use it beyond this range, but don't expect it to behave in any specific way. This is outside spec.)

hjust controls horizontal justification and vjust controls vertical justification.

An example should make this clear:

td <- expand.grid(
    hjust=c(0, 0.5, 1),
    vjust=c(0, 0.5, 1),
    angle=c(0, 45, 90),
    text="text"
)

ggplot(td, aes(x=hjust, y=vjust)) + 
    geom_point() +
    geom_text(aes(label=text, angle=angle, hjust=hjust, vjust=vjust)) + 
    facet_grid(~angle) +
    scale_x_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2)) +
    scale_y_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2))

enter image description here


To understand what happens when you change the hjust in axis text, you need to understand that the horizontal alignment for axis text is defined in relation not to the x-axis, but to the entire plot (where this includes the y-axis text). (This is, in my view, unfortunate. It would be much more useful to have the alignment relative to the axis.)

DF <- data.frame(x=LETTERS[1:3],y=1:3)
p <- ggplot(DF, aes(x,y)) + geom_point() + 
    ylab("Very long label for y") +
    theme(axis.title.y=element_text(angle=0))


p1 <- p + theme(axis.title.x=element_text(hjust=0)) + xlab("X-axis at hjust=0")
p2 <- p + theme(axis.title.x=element_text(hjust=0.5)) + xlab("X-axis at hjust=0.5")
p3 <- p + theme(axis.title.x=element_text(hjust=1)) + xlab("X-axis at hjust=1")

library(ggExtra)
align.plots(p1, p2, p3)

enter image description here


To explore what happens with vjust aligment of axis labels:

DF <- data.frame(x=c("a\na","b","cdefghijk","l"),y=1:4)
p <- ggplot(DF, aes(x,y)) + geom_point()

p1 <- p + theme(axis.text.x=element_text(vjust=0, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0")
p2 <- p + theme(axis.text.x=element_text(vjust=0.5, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0.5")
p3 <- p + theme(axis.text.x=element_text(vjust=1, colour="red")) + 
        xlab("X-axis labels aligned with vjust=1")


library(ggExtra)
align.plots(p1, p2, p3)

enter image description here

Javascript - Open a given URL in a new tab by clicking a button

<BUTTON NAME='my_button' VALUE=sequence_no TYPE='SUBMIT' style="background-color:transparent ; border:none; color:blue;" onclick="this.form.target='_blank';return true;"><u>open new page</u></BUTTON>

This button will look like a URL and can be opened in a new tab.

Declare global variables in Visual Studio 2010 and VB.NET

Public variables are a code smell - try to redesign your application so these are not needed. Most of the reasoning here and here are as applicable to VB.NET.

The simplest way to have global variables in VB.NET is to create public static variables on a class (declare a variable as Public Shared).

Convert PEM to PPK file format

  1. Download puttygen
  2. Then open puttygen
  3. click load
  4. Set the file type to . all files
  5. Save PrivateKey
  6. and then u can just save any name that file became an ppk file

Array vs. Object efficiency in JavaScript

I tried to take this to the next dimension, literally.

Given a 2 dimensional array, in which the x and y axes are always the same length, is it faster to:

a) look up the cell by creating a two dimensional array and looking up the first index, followed by the second index, i.e:

var arr=[][]    
var cell=[x][y]    

or

b) create an object with a string representation of the x and y coordinates, and then do a single lookup on that obj, i.e:

var obj={}    
var cell = obj['x,y']    

Result:
Turns out that it's much faster to do two numeric index lookups on the arrays, than one property lookup on the object.

Results here:

http://jsperf.com/arr-vs-obj-lookup-2

IIS 7, HttpHandler and HTTP Error 500.21

I had the same problem and just solved it. I had posted my own question on stackoverflow:

Can't PUT to my IHttpHandler, GET works fine

The solution was to set runManagedModulesForWebDavRequests to true in the modules element. My guess is that once you install WebDAV then all PUT requests are associated with it. If you need the PUT to go to your handler, you need to remove the WebDAV module and set this attribute to true.

<modules runManagedModulesForWebDavRequests="true">
...
</modules>

So if you're running into the problem when you use the PUT verb and you have installed WebDAV then hopefully this solution will fix your problem.

When do you use Git rebase instead of Git merge?

It was explained many times what rebase and what merge is, but when should you use what?

When should you use rebase?

Rebase "lifts off" your changes and puts all the changes of the rebased branch into your current branch and then puts your changes on top of it. It therefore changes the history of your branch.

  • when you have not pushed the branch / no one else is working on it
  • you want your to see all your changes at one point together when merging back to the source branch
  • you want to avoid the auto-generated "merged .." commit messages

I said "you want to see all your changes at one place" because sometimes a merge operation puts all your changes together in one commit (some: merged from ... message). Rebase makes your change look like you made your commits all after each other with no one else doing something in between. This makes it easier to see, what you changed for your feature.

Make sure though, you use git merge feature-branch --ff-only to make sure there are no conflicts creating a single commit when you are merging your feature back to develop/master.

When should you use merge?

  • when you have pushed the branch / others are working on it too (rebase gets very complicated if others work on that branch too!)
  • you don't need the full history(*) / your feature doesn't have to have it's commits all in one place.

(*) you can avoid that your feature only gets one "merged .." commits by first merging the develop branch to your feature and then merging your feature back to develeop. This still gives you a "merged .." commit, but a least all the commits of your feature are still visible.

5.7.57 SMTP - Client was not authenticated to send anonymous mail during MAIL FROM error

Try resetting your password for the email used. Had similar issue, and got it fixed only after changing password.

Remove directory which is not empty

While recursive is an experimental option of fs.rmdir

function rm (path, cb) {
    fs.stat(path, function (err, stats) {
        if (err)
            return cb(err);

        if (stats.isFile())
            return fs.unlink(path, cb);

        fs.rmdir(path, function (err) {
            if (!err || err && err.code != 'ENOTEMPTY') 
                return cb(err);

            fs.readdir(path, function (err, files) {
                if (err)
                    return cb(err);

                let next = i => i == files.length ? 
                    rm(path, cb) : 
                    rm(path + '/' + files[i], err => err ? cb(err) : next(i + 1));

                next(0);
            });
        });
    });
}

Access denied; you need (at least one of) the SUPER privilege(s) for this operation

When you restore backup, Make sure to try with the same username for the old one and the new one.

Call asynchronous method in constructor?

My preferred approach:

// caution: fire and forget
Task.Run(async () => await someAsyncFunc());

#1227 - Access denied; you need (at least one of) the SUPER privilege(s) for this operation

In my case there was no DEFINER or root@localhost mentioned in my SQL file. Actually I was trying to import and run SQL file into SQLYog from Database->Import->Execute SQL Script menu. That was giving error.

Then I copied all the script from SQL file and ran in SQLYog query editor. That worked perfectly fine.

Post order traversal of binary tree without recursion

I was looking for a code snippet that performs well and is simple to customise. Threaded trees are not “simple”. Double stack solution requires O(n) memory. LeetCode solution and solution by tcb have extra checks and pushes...

Here is one classic algorithm translated into C that worked for me:

void postorder_traversal(TreeNode *p, void (*visit)(TreeNode *))
{
    TreeNode   *stack[40];      // simple C stack, no overflow check
    TreeNode  **sp = stack;
    TreeNode   *last_visited = NULL;

    for (; p != NULL; p = p->left)
        *sp++ = p;

    while (sp != stack) {
        p = sp[-1];
        if (p->right == NULL || p->right == last_visited) {
            visit(p);
            last_visited = p;
            sp--;
        } else {
            for (p = p->right; p != NULL; p = p->left)
                *sp++ = p;
        }
    }
}

IMHO this algorithm is easier to follow than well performing and readable wikipedia.org / Tree_traversal pseudocode. For glorious details see answers to binary tree exercises in Knuth’s Volume 1.

How do I parse a string with a decimal point to a double?

I think 100% correct conversion isn't possible, if the value comes from a user input. e.g. if the value is 123.456, it can be a grouping or it can be a decimal point. If you really need 100% you have to describe your format and throw an exception if it is not correct.

But I improved the code of JanW, so we get a little bit more ahead to the 100%. The idea behind is, that if the last separator is a groupSeperator, this would be more an integer type, than a double.

The added code is in the first if of GetDouble.

void Main()
{
    List<string> inputs = new List<string>() {
        "1.234.567,89",
        "1 234 567,89",
        "1 234 567.89",
        "1,234,567.89",
        "1234567,89",
        "1234567.89",
        "123456789",
        "123.456.789",
        "123,456,789,"
    };

    foreach(string input in inputs) {
        Console.WriteLine(GetDouble(input,0d));
    }

}

public static double GetDouble(string value, double defaultValue) {
    double result;
    string output;

    // Check if last seperator==groupSeperator
    string groupSep = System.Globalization.CultureInfo.CurrentCulture.NumberFormat.NumberGroupSeparator;
    if (value.LastIndexOf(groupSep) + 4 == value.Count())
    {
        bool tryParse = double.TryParse(value, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.CurrentCulture, out result);
        result = tryParse ? result : defaultValue;
    }
    else
    {
        // Unify string (no spaces, only . )
        output = value.Trim().Replace(" ", string.Empty).Replace(",", ".");

        // Split it on points
        string[] split = output.Split('.');

        if (split.Count() > 1)
        {
            // Take all parts except last
            output = string.Join(string.Empty, split.Take(split.Count()-1).ToArray());

            // Combine token parts with last part
            output = string.Format("{0}.{1}", output, split.Last());
        }
        // Parse double invariant
        result = double.Parse(output, System.Globalization.CultureInfo.InvariantCulture);
    }
    return result;
}

How to convert datetime to integer in python

When converting datetime to integers one must keep in mind the tens, hundreds and thousands.... like "2018-11-03" must be like 20181103 in int for that you have to 2018*10000 + 100* 11 + 3

Similarly another example, "2018-11-03 10:02:05" must be like 20181103100205 in int

Explanatory Code

dt = datetime(2018,11,3,10,2,5)
print (dt)

#print (dt.timestamp()) # unix representation ... not useful when converting to int

print (dt.strftime("%Y-%m-%d"))
print (dt.year*10000 + dt.month* 100  + dt.day)
print (int(dt.strftime("%Y%m%d")))

print (dt.strftime("%Y-%m-%d %H:%M:%S"))
print (dt.year*10000000000 + dt.month* 100000000 +dt.day * 1000000 + dt.hour*10000  +  dt.minute*100 + dt.second)
print (int(dt.strftime("%Y%m%d%H%M%S")))

General Function

To avoid that doing manually use below function

def datetime_to_int(dt):
    return int(dt.strftime("%Y%m%d%H%M%S"))

Checking if float is an integer

Keep in mind that most of the techniques here are valid presuming that round-off error due to prior calculations is not a factor. E.g. you could use roundf, like this:

float z = 1.0f;

if (roundf(z) == z) {
    printf("integer\n");
} else {
    printf("fraction\n");
}

The problem with this and other similar techniques (such as ceilf, casting to long, etc.) is that, while they work great for whole number constants, they will fail if the number is a result of a calculation that was subject to floating-point round-off error. For example:

float z = powf(powf(3.0f, 0.05f), 20.0f);

if (roundf(z) == z) {
    printf("integer\n");
} else {
    printf("fraction\n");
}

Prints "fraction", even though (31/20)20 should equal 3, because the actual calculation result ended up being 2.9999992847442626953125.

Any similar method, be it fmodf or whatever, is subject to this. In applications that perform complex or rounding-prone calculations, usually what you want to do is define some "tolerance" value for what constitutes a "whole number" (this goes for floating-point equality comparisons in general). We often call this tolerance epsilon. For example, lets say that we'll forgive the computer for up to +/- 0.00001 rounding error. Then, if we are testing z, we can choose an epsilon of 0.00001 and do:

if (fabsf(roundf(z) - z) <= 0.00001f) {
    printf("integer\n");
} else {
    printf("fraction\n");
}

You don't really want to use ceilf here because e.g. ceilf(1.0000001) is 2 not 1, and ceilf(-1.99999999) is -1 not -2.

You could use rintf in place of roundf if you prefer.

Choose a tolerance value that is appropriate for your application (and yes, sometimes zero tolerance is appropriate). For more information, check out this article on comparing floating-point numbers.

How could I convert data from string to long in c#

long is internally represented as System.Int64 which is a 64-bit signed integer. The value you have taken "1100.25" is actually decimal and not integer hence it can not be converted to long.

You can use:

String strValue = "1100.25";
decimal lValue = Convert.ToDecimal(strValue);

to convert it to decimal value

document.getElementById vs jQuery $()

All the answers above are correct. In case you want to see it in action, don't forget you have Console in a browser where you can see the actual result crystal clear :

I have an HTML :

<div id="contents"></div>

Go to console (cntrl+shift+c) and use these commands to see your result clearly

document.getElementById('contents')
>>> div#contents

$('#contents')
>>> [div#contents,
 context: document,
 selector: "#contents",
 jquery: "1.10.1",
 constructor: function,
 init: function …]

As we can see, in the first case we got the tag itself (that is, strictly speaking, an HTMLDivElement object). In the latter we actually don’t have a plain object, but an array of objects. And as mentioned by other answers above, you can use the following command:

$('#contents')[0]
>>> div#contents

Iterating through a string word by word

Using nltk.

from nltk.tokenize import sent_tokenize, word_tokenize
sentences = sent_tokenize("This is a string.")
words_in_each_sentence = word_tokenize(sentences)

You may use TweetTokenizer for parsing casual text with emoticons and such.

How to deal with SettingWithCopyWarning in Pandas

In general the point of the SettingWithCopyWarning is to show users (and especially new users) that they may be operating on a copy and not the original as they think. There are false positives (IOW if you know what you are doing it could be ok). One possibility is simply to turn off the (by default warn) warning as @Garrett suggest.

Here is another option:

In [1]: df = DataFrame(np.random.randn(5, 2), columns=list('AB'))

In [2]: dfa = df.ix[:, [1, 0]]

In [3]: dfa.is_copy
Out[3]: True

In [4]: dfa['A'] /= 2
/usr/local/bin/ipython:1: SettingWithCopyWarning: A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_index,col_indexer] = value instead
  #!/usr/local/bin/python

You can set the is_copy flag to False, which will effectively turn off the check, for that object:

In [5]: dfa.is_copy = False

In [6]: dfa['A'] /= 2

If you explicitly copy then no further warning will happen:

In [7]: dfa = df.ix[:, [1, 0]].copy()

In [8]: dfa['A'] /= 2

The code the OP is showing above, while legitimate, and probably something I do as well, is technically a case for this warning, and not a false positive. Another way to not have the warning would be to do the selection operation via reindex, e.g.

quote_df = quote_df.reindex(columns=['STK', ...])

Or,

quote_df = quote_df.reindex(['STK', ...], axis=1)  # v.0.21

The infamous java.sql.SQLException: No suitable driver found

I was having the same issue with mysql datasource using spring data that would work outside but gave me this error when deployed on tomcat.

The error went away when I added the driver jar mysql-connector-java-8.0.16.jar to the jres lib/ext folder

However I did not want to do this in production for fear of interfering with other applications. Explicity defining the driver class solved this issue for me

    spring.datasource.driver-class-name: com.mysql.cj.jdbc.Driver

UTF-8 output from PowerShell

This is a bug in .NET. When PowerShell launches, it caches the output handle (Console.Out). The Encoding property of that text writer does not pick up the value StandardOutputEncoding property.

When you change it from within PowerShell, the Encoding property of the cached output writer returns the cached value, so the output is still encoded with the default encoding.

As a workaround, I would suggest not changing the encoding. It will be returned to you as a Unicode string, at which point you can manage the encoding yourself.

Caching example:

102 [C:\Users\leeholm]
>> $r1 = [Console]::Out

103 [C:\Users\leeholm]
>> $r1

Encoding                                          FormatProvider
--------                                          --------------
System.Text.SBCSCodePageEncoding                  en-US



104 [C:\Users\leeholm]
>> [Console]::OutputEncoding = [System.Text.Encoding]::UTF8

105 [C:\Users\leeholm]
>> $r1

Encoding                                          FormatProvider
--------                                          --------------
System.Text.SBCSCodePageEncoding                  en-US

How to loop through all enum values in C#?

foreach (Foos foo in Enum.GetValues(typeof(Foos)))
{
    ...
}

"Insert if not exists" statement in SQLite

If you have a table called memos that has two columns id and text you should be able to do like this:

INSERT INTO memos(id,text) 
SELECT 5, 'text to insert' 
WHERE NOT EXISTS(SELECT 1 FROM memos WHERE id = 5 AND text = 'text to insert');

If a record already contains a row where text is equal to 'text to insert' and id is equal to 5, then the insert operation will be ignored.

I don't know if this will work for your particular query, but perhaps it give you a hint on how to proceed.

I would advice that you instead design your table so that no duplicates are allowed as explained in @CLs answer below.

Factorial in numpy and scipy

    from numpy import prod

    def factorial(n):
        print prod(range(1,n+1))

or with mul from operator:

    from operator import mul

    def factorial(n):
        print reduce(mul,range(1,n+1))

or completely without help:

    def factorial(n):
        print reduce((lambda x,y: x*y),range(1,n+1))

How to set TextView textStyle such as bold, italic

1) You can set it with TypeFace. 2) You can directly use in strings.xml(in your values folder) 3) You can String myNewString = " This is my bold text This is my italics string This is my underlined string

Spring MVC: Complex object as GET @RequestParam

You can absolutely do that, just remove the @RequestParam annotation, Spring will cleanly bind your request parameters to your class instance:

public @ResponseBody List<MyObject> myAction(
    @RequestParam(value = "page", required = false) int page,
    MyObject myObject)

java.io.FileNotFoundException: the system cannot find the file specified

Your file should directly be under the project folder, and not inside any other sub-folder.

If the folder of your project is named for e.g. AProject, it should be in the same place as your src folder.

Aproject
        src
        word.txt

How to change the background color on a input checkbox with css?

I always use pseudo elements :before and :after for changing the appearance of checkboxes and radio buttons. it's works like a charm.

Refer this link for more info

CODEPEN

Steps

  1. Hide the default checkbox using css rules like visibility:hidden or opacity:0 or position:absolute;left:-9999px etc.
  2. Create a fake checkbox using :before element and pass either an empty or a non-breaking space '\00a0';
  3. When the checkbox is in :checked state, pass the unicode content: "\2713", which is a checkmark;
  4. Add :focus style to make the checkbox accessible.
  5. Done

Here is how I did it.

_x000D_
_x000D_
.box {_x000D_
  background: #666666;_x000D_
  color: #ffffff;_x000D_
  width: 250px;_x000D_
  padding: 10px;_x000D_
  margin: 1em auto;_x000D_
}_x000D_
p {_x000D_
  margin: 1.5em 0;_x000D_
  padding: 0;_x000D_
}_x000D_
input[type="checkbox"] {_x000D_
  visibility: hidden;_x000D_
}_x000D_
label {_x000D_
  cursor: pointer;_x000D_
}_x000D_
input[type="checkbox"] + label:before {_x000D_
  border: 1px solid #333;_x000D_
  content: "\00a0";_x000D_
  display: inline-block;_x000D_
  font: 16px/1em sans-serif;_x000D_
  height: 16px;_x000D_
  margin: 0 .25em 0 0;_x000D_
  padding: 0;_x000D_
  vertical-align: top;_x000D_
  width: 16px;_x000D_
}_x000D_
input[type="checkbox"]:checked + label:before {_x000D_
  background: #fff;_x000D_
  color: #333;_x000D_
  content: "\2713";_x000D_
  text-align: center;_x000D_
}_x000D_
input[type="checkbox"]:checked + label:after {_x000D_
  font-weight: bold;_x000D_
}_x000D_
_x000D_
input[type="checkbox"]:focus + label::before {_x000D_
    outline: rgb(59, 153, 252) auto 5px;_x000D_
}
_x000D_
<div class="content">_x000D_
  <div class="box">_x000D_
    <p>_x000D_
      <input type="checkbox" id="c1" name="cb">_x000D_
      <label for="c1">Option 01</label>_x000D_
    </p>_x000D_
    <p>_x000D_
      <input type="checkbox" id="c2" name="cb">_x000D_
      <label for="c2">Option 02</label>_x000D_
    </p>_x000D_
    <p>_x000D_
      <input type="checkbox" id="c3" name="cb">_x000D_
      <label for="c3">Option 03</label>_x000D_
    </p>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Much more stylish using :before and :after

_x000D_
_x000D_
body{_x000D_
  font-family: sans-serif;  _x000D_
}_x000D_
_x000D_
.container {_x000D_
    margin-top: 50px;_x000D_
    margin-left: 20px;_x000D_
    margin-right: 20px;_x000D_
}_x000D_
.checkbox {_x000D_
    width: 100%;_x000D_
    margin: 15px auto;_x000D_
    position: relative;_x000D_
    display: block;_x000D_
}_x000D_
_x000D_
.checkbox input[type="checkbox"] {_x000D_
    width: auto;_x000D_
    opacity: 0.00000001;_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    margin-left: -20px;_x000D_
}_x000D_
.checkbox label {_x000D_
    position: relative;_x000D_
}_x000D_
.checkbox label:before {_x000D_
    content: '';_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    top: 0;_x000D_
    margin: 4px;_x000D_
    width: 22px;_x000D_
    height: 22px;_x000D_
    transition: transform 0.28s ease;_x000D_
    border-radius: 3px;_x000D_
    border: 2px solid #7bbe72;_x000D_
}_x000D_
.checkbox label:after {_x000D_
  content: '';_x000D_
    display: block;_x000D_
    width: 10px;_x000D_
    height: 5px;_x000D_
    border-bottom: 2px solid #7bbe72;_x000D_
    border-left: 2px solid #7bbe72;_x000D_
    -webkit-transform: rotate(-45deg) scale(0);_x000D_
    transform: rotate(-45deg) scale(0);_x000D_
    transition: transform ease 0.25s;_x000D_
    will-change: transform;_x000D_
    position: absolute;_x000D_
    top: 12px;_x000D_
    left: 10px;_x000D_
}_x000D_
.checkbox input[type="checkbox"]:checked ~ label::before {_x000D_
    color: #7bbe72;_x000D_
}_x000D_
_x000D_
.checkbox input[type="checkbox"]:checked ~ label::after {_x000D_
    -webkit-transform: rotate(-45deg) scale(1);_x000D_
    transform: rotate(-45deg) scale(1);_x000D_
}_x000D_
_x000D_
.checkbox label {_x000D_
    min-height: 34px;_x000D_
    display: block;_x000D_
    padding-left: 40px;_x000D_
    margin-bottom: 0;_x000D_
    font-weight: normal;_x000D_
    cursor: pointer;_x000D_
    vertical-align: sub;_x000D_
}_x000D_
.checkbox label span {_x000D_
    position: absolute;_x000D_
    top: 50%;_x000D_
    -webkit-transform: translateY(-50%);_x000D_
    transform: translateY(-50%);_x000D_
}_x000D_
.checkbox input[type="checkbox"]:focus + label::before {_x000D_
    outline: 0;_x000D_
}
_x000D_
<div class="container"> _x000D_
  <div class="checkbox">_x000D_
     <input type="checkbox" id="checkbox" name="" value="">_x000D_
     <label for="checkbox"><span>Checkbox</span></label>_x000D_
  </div>_x000D_
_x000D_
  <div class="checkbox">_x000D_
     <input type="checkbox" id="checkbox2" name="" value="">_x000D_
     <label for="checkbox2"><span>Checkbox</span></label>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Create list or arrays in Windows Batch

Yes, you may use both ways. If you just want to separate the elements and show they in separated lines, a list is simpler:

set list=A B C D

A list of values separated by space may be easily processed by for command:

(for %%a in (%list%) do (
   echo %%a
   echo/
)) > theFile.txt

You may also create an array this way:

setlocal EnableDelayedExpansion
set n=0
for %%a in (A B C D) do (
   set vector[!n!]=%%a
   set /A n+=1
)

and show the array elements this way:

(for /L %%i in (0,1,3) do (
   echo !vector[%%i]!
   echo/
)) > theFile.txt

For further details about array management in Batch files, see: Arrays, linked lists and other data structures in cmd.exe (batch) script

ATTENTION! You must know that all characters included in set command are inserted in the variable name (at left of equal sign), or in the variable value. For example, this command:

set list = "A B C D"

create a variable called list (list-space) with the value "A B C D" (space, quote, A, etc). For this reason, it is a good idea to never insert spaces in set commands. If you need to enclose the value in quotes, you must enclose both the variable name and its value:

set "list=A B C D"

PS - You should NOT use ECHO. in order to left blank lines! An alternative is ECHO/. For further details about this point, see: http://www.dostips.com/forum/viewtopic.php?f=3&t=774

Objective-C ARC: strong vs retain and weak vs assign

After reading so many articles Stackoverflow posts and demo applications to check variable property attributes, I decided to put all the attributes information together:

  1. atomic //default
  2. nonatomic
  3. strong=retain //default
  4. weak
  5. retain
  6. assign //default
  7. unsafe_unretained
  8. copy
  9. readonly
  10. readwrite //default

Below is the detailed article link where you can find above mentioned all attributes, that will definitely help you. Many thanks to all the people who give best answers here!!

Variable property attributes or Modifiers in iOS

1.strong (iOS4 = retain )

  • it says "keep this in the heap until I don't point to it anymore"
  • in other words " I'am the owner, you cannot dealloc this before aim fine with that same as retain"
  • You use strong only if you need to retain the object.
  • By default all instance variables and local variables are strong pointers.
  • We generally use strong for UIViewControllers (UI item's parents)
  • strong is used with ARC and it basically helps you , by not having to worry about the retain count of an object. ARC automatically releases it for you when you are done with it.Using the keyword strong means that you own the object.

Example:

@property (strong, nonatomic) ViewController *viewController;

@synthesize viewController;

2.weak -

  • it says "keep this as long as someone else points to it strongly"
  • the same thing as assign, no retain or release
  • A "weak" reference is a reference that you do not retain.
  • We generally use weak for IBOutlets (UIViewController's Childs).This works because the child object only needs to exist as long as the parent object does.
  • a weak reference is a reference that does not protect the referenced object from collection by a garbage collector.
  • Weak is essentially assign, a unretained property. Except the when the object is deallocated the weak pointer is automatically set to nil

Example :

@property (weak, nonatomic) IBOutlet UIButton *myButton;

@synthesize myButton;

Strong & Weak Explanation, Thanks to BJ Homer:

Imagine our object is a dog, and that the dog wants to run away (be deallocated).

Strong pointers are like a leash on the dog. As long as you have the leash attached to the dog, the dog will not run away. If five people attach their leash to one dog, (five strong pointers to one object), then the dog will not run away until all five leashes are detached.

Weak pointers, on the other hand, are like little kids pointing at the dog and saying "Look! A dog!" As long as the dog is still on the leash, the little kids can still see the dog, and they'll still point to it. As soon as all the leashes are detached, though, the dog runs away no matter how many little kids are pointing to it.

As soon as the last strong pointer (leash) no longer points to an object, the object will be deallocated, and all weak pointers will be zeroed out.

When we use weak?

The only time you would want to use weak, is if you wanted to avoid retain cycles (e.g. the parent retains the child and the child retains the parent so neither is ever released).

3.retain = strong

  • it is retained, old value is released and it is assigned retain specifies the new value should be sent
  • retain on assignment and the old value sent -release
  • retain is the same as strong.
  • apple says if you write retain it will auto converted/work like strong only.
  • methods like "alloc" include an implicit "retain"

Example:

@property (nonatomic, retain) NSString *name;

@synthesize name;

4.assign

  • assign is the default and simply performs a variable assignment
  • assign is a property attribute that tells the compiler how to synthesize the property's setter implementation
  • I would use assign for C primitive properties and weak for weak references to Objective-C objects.

Example:

@property (nonatomic, assign) NSString *address;

@synthesize address;

How to generate a random integer number from within a range

Here is a slight simpler algorithm than Ryan Reich's solution:

/// Begin and end are *inclusive*; => [begin, end]
uint32_t getRandInterval(uint32_t begin, uint32_t end) {
    uint32_t range = (end - begin) + 1;
    uint32_t limit = ((uint64_t)RAND_MAX + 1) - (((uint64_t)RAND_MAX + 1) % range);

    /* Imagine range-sized buckets all in a row, then fire randomly towards
     * the buckets until you land in one of them. All buckets are equally
     * likely. If you land off the end of the line of buckets, try again. */
    uint32_t randVal = rand();
    while (randVal >= limit) randVal = rand();

    /// Return the position you hit in the bucket + begin as random number
    return (randVal % range) + begin;
}

Example (RAND_MAX := 16, begin := 2, end := 7)
    => range := 6  (1 + end - begin)
    => limit := 12 (RAND_MAX + 1) - ((RAND_MAX + 1) % range)

The limit is always a multiple of the range,
so we can split it into range-sized buckets:
    Possible-rand-output: 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16
    Buckets:             [0, 1, 2, 3, 4, 5][0, 1, 2, 3, 4, 5][X, X, X, X, X]
    Buckets + begin:     [2, 3, 4, 5, 6, 7][2, 3, 4, 5, 6, 7][X, X, X, X, X]

1st call to rand() => 13
    ? 13 is not in the bucket-range anymore (>= limit), while-condition is true
        ? retry...
2nd call to rand() => 7
    ? 7 is in the bucket-range (< limit), while-condition is false
        ? Get the corresponding bucket-value 1 (randVal % range) and add begin
    => 3

How to insert data into elasticsearch

If you are using KIBANA with elasticsearch then you can use below RESt request to create and put in the index.

CREATING INDEX:

http://localhost:9200/company
PUT company
{
  "settings": {
    "index": {
      "number_of_shards": 1,
      "number_of_replicas": 1
    },
    "analysis": {
      "analyzer": {
        "analyzer-name": {
          "type": "custom",
          "tokenizer": "keyword",
          "filter": "lowercase"
        }
      }
    }
  },
  "mappings": {
    "employee": {
      "properties": {
        "age": {
          "type": "long"
        },
        "experience": {
          "type": "long"
        },
        "name": {
          "type": "text",
          "analyzer": "analyzer-name"
        }
      }
    }
  }
}

CREATING DOCUMENT:

POST http://localhost:9200/company/employee/2/_create
{
"name": "Hemani",
"age" : 23,
"experienceInYears" : 2
}

Style disabled button with CSS

I think you should be able to select a disabled button using the following:

button[disabled=disabled], button:disabled {
    // your css rules
}

How to get current url in view in asp.net core 1.0

The accepted answer helped me, as did the comment for it from @padigan but if you want to include the query-string parameters as was the case for me then try this:

@[email protected]()

And you will need to add @using Microsoft.AspNetCore.Http.Extensions in the view in order for the GetEncodedPathAndQuery() method to be available.

make: Nothing to be done for `all'

When you just give make, it makes the first rule in your makefile, i.e "all". You have specified that "all" depends on "hello", which depends on main.o, factorial.o and hello.o. So 'make' tries to see if those files are present.

If they are present, 'make' sees if their dependencies, e.g. main.o has a dependency main.c, have changed. If they have changed, make rebuilds them, else skips the rule. Similarly it recursively goes on building the files that have changed and finally runs the top most command, "all" in your case to give you a executable, 'hello' in your case.

If they are not present, make blindly builds everything under the rule.

Coming to your problem, it isn't an error but 'make' is saying that every dependency in your makefile is up to date and it doesn't need to make anything!

Pandas: Subtracting two date columns and the result being an integer

You can divide column of dtype timedelta by np.timedelta64(1, 'D'), but output is not int, but float, because NaN values:

df_test['Difference'] = df_test['Difference'] / np.timedelta64(1, 'D')
print (df_test)
  First_Date Second Date  Difference
0 2016-02-09  2015-11-19        82.0
1 2016-01-06  2015-11-30        37.0
2        NaT  2015-12-04         NaN
3 2016-01-06  2015-12-08        29.0
4        NaT  2015-12-09         NaN
5 2016-01-07  2015-12-11        27.0
6        NaT  2015-12-12         NaN
7        NaT  2015-12-14         NaN
8 2016-01-06  2015-12-14        23.0
9        NaT  2015-12-15         NaN

Frequency conversion.

What is the difference between JavaScript and ECMAScript?

ECMAScript is the language, whereas JavaScript, JScript, and even ActionScript 3 are called "dialects". Wikipedia sheds some light on this.

Python socket connection timeout

For setting the Socket timeout, you need to follow these steps:

import socket
socks = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socks.settimeout(10.0) # settimeout is the attr of socks.

jQuery check if it is clicked or not

You could use .data():

$("#element").click(function(){
    $(this).data('clicked', true);
});

and then check it with:

if($('#element').data('clicked')) {
    alert('yes');
}

To get a better answer you need to provide more information.

Update:

Based on your comment, I understand you want something like:

$("#element").click(function(){
    var $this = $(this);
    if($this.data('clicked')) {
        func(some, other, parameters);
    }
    else {
        $this.data('clicked', true);
        func(some, parameter);
    }
});

Pass variable to function in jquery AJAX success callback

You can't pass parameters like this - the success object maps to an anonymous function with one parameter and that's the received data. Create a function outside of the for loop which takes (data, i) as parameters and perform the code there:

function image_link(data, i) {
   $(data).find("a:contains(.jpg)").each(function(){                                
       new Image().src = url[i] + $(this).attr("href");
   }
}
...
success: function(data){
    image_link(data, i)
}

Round double value to 2 decimal places

I use the solution posted by Umberto Raimondi extending type Double:

extension Double {
    func roundTo(places:Int) -> Double {
        let divisor = pow(10.0, Double(places))
        return (self * divisor).rounded() / divisor
    }
}

What is dynamic programming?

Dynamic programming is a technique used to avoid computing multiple times the same subproblem in a recursive algorithm.

Let's take the simple example of the Fibonacci numbers: finding the n th Fibonacci number defined by

Fn = Fn-1 + Fn-2 and F0 = 0, F1 = 1

Recursion

The obvious way to do this is recursive:

def fibonacci(n):
    if n == 0:
        return 0
    if n == 1:
        return 1

    return fibonacci(n - 1) + fibonacci(n - 2)

Dynamic Programming

  • Top Down - Memoization

The recursion does a lot of unnecessary calculations because a given Fibonacci number will be calculated multiple times. An easy way to improve this is to cache the results:

cache = {}

def fibonacci(n):
    if n == 0:
        return 0
    if n == 1:
        return 1
    if n in cache:
        return cache[n]

    cache[n] = fibonacci(n - 1) + fibonacci(n - 2)

    return cache[n]
  • Bottom-Up

A better way to do this is to get rid of the recursion all-together by evaluating the results in the right order:

cache = {}

def fibonacci(n):
    cache[0] = 0
    cache[1] = 1

    for i in range(2, n + 1):
        cache[i] = cache[i - 1] +  cache[i - 2]

    return cache[n]

We can even use constant space and store only the necessary partial results along the way:

def fibonacci(n):
  fi_minus_2 = 0
  fi_minus_1 = 1

  for i in range(2, n + 1):
      fi = fi_minus_1 + fi_minus_2
      fi_minus_1, fi_minus_2 = fi, fi_minus_1

  return fi
  • How apply dynamic programming?

    1. Find the recursion in the problem.
    2. Top-down: store the answer for each subproblem in a table to avoid having to recompute them.
    3. Bottom-up: Find the right order to evaluate the results so that partial results are available when needed.

Dynamic programming generally works for problems that have an inherent left to right order such as strings, trees or integer sequences. If the naive recursive algorithm does not compute the same subproblem multiple times, dynamic programming won't help.

I made a collection of problems to help understand the logic: https://github.com/tristanguigue/dynamic-programing

Why split the <script> tag when writing it with document.write()?

Here's another variation I've used when wanting to generate a script tag inline (so it executes immediately) without needing any form of escapes:

<script>
    var script = document.createElement('script');
    script.src = '/path/to/script.js';
    document.write(script.outerHTML);
</script>

(Note: contrary to most examples on the net, I'm not setting type="text/javascript" on neither the enclosing tag, nor the generated one: there is no browser not having that as the default, and so it is redundant, but will not hurt either, if you disagree).

jQuery add required to input fields

I found that jquery 1.11.1 does not do this reliably.

I used $('#estimate').attr('required', true) and $('#estimate').removeAttr('required').

Removing required was not reliable. It would sometimes leave the required attribute without value. Since required is a boolean attibute, its mere presence, without value, is seen by the browser as true.

This bug was intermittent, and I got tired of messing with it. Switched to document.getElementById("estimate").required = true and document.getElementById("estimate").required = false.

How to get the query string by javascript?

Works for me-

function querySt(Key) {

    var url = window.location.href;

    KeysValues = url.split(/[\?&]+/); 

    for (i = 0; i < KeysValues.length; i++) {

            KeyValue= KeysValues[i].split("=");

            if (KeyValue[0] == Key) {

                return KeyValue[1];

        }

    }

}

function GetQString(Key) {     

    if (querySt(Key)) {

         var value = querySt(Key);

         return value;        

    }

 }

How to recognize swipe in all 4 directions

For Swift 5 it's updated

//Add in ViewDidLoad
let gesture = UISwipeGestureRecognizer(target: self, action: #selector(ViewController.handleSwipe))
        gesture.direction = .right
        self.view.addGestureRecognizer(gesture)

//Add New Method
@objc func handleSwipe(sender: UISwipeGestureRecognizer) {
        print("swipe direction is",sender.direction)

    }

How to increase memory limit for PHP over 2GB?

You should have 64-bit OS on hardware that supports 64-bit OS, 64-bit Apache version and the same for PHP. But this does not guarantee that functions that are work with PDF can use such big sizes of memory. You'd better not load the whole file into memory, split it into chunks or use file functions to seek on it without loading to RAM.

What's the fastest way to do a bulk insert into Postgres?

The external file is the best and typical bulk-data

The term "bulk data" is related to "a lot of data", so it is natural to use original raw data, with no need to transform it into SQL. Typical raw data files for "bulk insert" are CSV and JSON formats.

Bulk insert with some transformation

In ETL applications and ingestion processes, we need to change the data before inserting it. Temporary table consumes (a lot of) disk space, and it is not the faster way to do it. The PostgreSQL foreign-data wrapper (FDW) is the best choice.

CSV example. Suppose the tablename (x, y, z) on SQL and a CSV file like

fieldname1,fieldname2,fieldname3
etc,etc,etc
... million lines ...

You can use the classic SQL COPY to load (as is original data) into tmp_tablename, them insert filtered data into tablename... But, to avoid disk consumption, the best is to ingested directly by

INSERT INTO tablename (x, y, z)
  SELECT f1(fieldname1), f2(fieldname2), f3(fieldname3) -- the transforms 
  FROM tmp_tablename_fdw
  -- WHERE condictions
;

You need to prepare database for FDW, and instead static tmp_tablename_fdw you can use a function that generates it:

CREATE EXTENSION file_fdw;
CREATE SERVER import FOREIGN DATA WRAPPER file_fdw;
CREATE FOREIGN TABLE tmp_tablename_fdw(
  ...
) SERVER import OPTIONS ( filename '/tmp/pg_io/file.csv', format 'csv');

JSON example. A set of two files, myRawData1.json and Ranger_Policies2.json can be ingested by:

INSERT INTO tablename (fname, metadata, content)
 SELECT fname, meta, j  -- do any data transformation here
 FROM jsonb_read_files('myRawData%.json')
 -- WHERE any_condiction_here
;

where the function jsonb_read_files() reads all files of a folder, defined by a mask:

CREATE or replace FUNCTION jsonb_read_files(
  p_flike text, p_fpath text DEFAULT '/tmp/pg_io/'
) RETURNS TABLE (fid int,  fname text, fmeta jsonb, j jsonb) AS $f$
  WITH t AS (
     SELECT (row_number() OVER ())::int id, 
           f as fname,
           p_fpath ||'/'|| f as f
     FROM pg_ls_dir(p_fpath) t(f)
     WHERE    f like p_flike
  ) SELECT id,  fname,
         to_jsonb( pg_stat_file(f) ) || jsonb_build_object('fpath',p_fpath),
         pg_read_file(f)::jsonb
    FROM t
$f$  LANGUAGE SQL IMMUTABLE;

Lack of gzip streaming

The most frequent method for "file ingestion" (mainlly in Big Data) is preserving original file on gzip format and transfering it with streaming algorithm, anything that can runs fast and without disc consumption in unix pipes:

 gunzip remote_or_local_file.csv.gz | convert_to_sql | psql 

So ideal (future) is a server option for format .csv.gz.

How to select first parent DIV using jQuery?

Use .closest() to traverse up the DOM tree up to the specified selector.

var classes = $(this).parent().closest('div').attr('class').split(' '); // this gets the parent classes.

How to convert UTF-8 byte[] to string?

Using (byte)b.ToString("x2"), Outputs b4b5dfe475e58b67

public static class Ext {

    public static string ToHexString(this byte[] hex)
    {
        if (hex == null) return null;
        if (hex.Length == 0) return string.Empty;

        var s = new StringBuilder();
        foreach (byte b in hex) {
            s.Append(b.ToString("x2"));
        }
        return s.ToString();
    }

    public static byte[] ToHexBytes(this string hex)
    {
        if (hex == null) return null;
        if (hex.Length == 0) return new byte[0];

        int l = hex.Length / 2;
        var b = new byte[l];
        for (int i = 0; i < l; ++i) {
            b[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
        }
        return b;
    }

    public static bool EqualsTo(this byte[] bytes, byte[] bytesToCompare)
    {
        if (bytes == null && bytesToCompare == null) return true; // ?
        if (bytes == null || bytesToCompare == null) return false;
        if (object.ReferenceEquals(bytes, bytesToCompare)) return true;

        if (bytes.Length != bytesToCompare.Length) return false;

        for (int i = 0; i < bytes.Length; ++i) {
            if (bytes[i] != bytesToCompare[i]) return false;
        }
        return true;
    }

}

Python assigning multiple variables to same value? list behavior

The code that does what I need could be this:

# test

aux=[[0 for n in range(3)] for i in range(4)]
print('aux:',aux)

# initialization

a,b,c,d=[[0 for n in range(3)] for i in range(4)]

# changing values

a[0]=1
d[2]=5
print('a:',a)
print('b:',b)
print('c:',c)
print('d:',d)

Result:

('aux:', [[0, 0, 0], [0, 0, 0], [0, 0, 0], [0, 0, 0]])
('a:', [1, 0, 0])
('b:', [0, 0, 0])
('c:', [0, 0, 0])
('d:', [0, 0, 5])

How to declare strings in C

Strings in C are represented as arrays of characters.

char *p = "String";

You are declaring a pointer that points to a string stored some where in your program (modifying this string is undefined behavior) according to the C programming language 2 ed.

char p2[] = "String";

You are declaring an array of char initialized with the string "String" leaving to the compiler the job to count the size of the array.

char p3[5] = "String";

You are declaring an array of size 5 and initializing it with "String". This is an error be cause "String" don't fit in 5 elements.

char p3[7] = "String"; is the correct declaration ('\0' is the terminating character in c strings).

http://c-faq.com/~scs/cclass/notes/sx8.html

How do I get the different parts of a Flask request's url?

If you are using Python, I would suggest by exploring the request object:

dir(request)

Since the object support the method dict:

request.__dict__

It can be printed or saved. I use it to log 404 codes in Flask:

@app.errorhandler(404)
def not_found(e):
    with open("./404.csv", "a") as f:
        f.write(f'{datetime.datetime.now()},{request.__dict__}\n')
    return send_file('static/images/Darknet-404-Page-Concept.png', mimetype='image/png')