Programs & Examples On #Multifile

Ambiguous overload call to abs(double)

Use fabs() instead of abs(), it's the same but for floats instead of integers.

Error Message: Type or namespace definition, or end-of-file expected

  1. Make sure you have System.Web referenced
  2. Get rid of the two } at the end.

PHP - Move a file into a different folder on the server

Use file this code

function move_file($path,$to){
   if(copy($path, $to)){
      unlink($path);
      return true;
   } else {
     return false;
   }
 }

Setting different color for each series in scatter plot on matplotlib

This works for me:

for each series, use a random rgb colour generator

c = color[np.random.random_sample(), np.random.random_sample(), np.random.random_sample()]

Why does ANT tell me that JAVA_HOME is wrong when it is not?

The semicolon was throwing me off: I had JAVA_HOME set to "C:\jdk1.6.0_26;" instead of "C:\jdk1.6.0_26". I removed the trailing semicolon after following Jon Skeet's suggestion to examine the ant.bat file. This is part of that file:

if "%JAVA_HOME%" == "" goto noJavaHome
if not exist "%JAVA_HOME%\bin\java.exe" goto noJavaHome

So the semi-colon wasn't being trimmed off the end, causing this to fail to find the file, therefore defaulting to "C:\Java\jre6" or something like that.

The confusing part is that the HowtoBuild page states to use the semi-colon, but that seems to break it.

C# difference between == and Equals()

Because the static version of the .Equal method was not mentioned so far, I would like to add this here to summarize and to compare the 3 variations.

MyString.Equals("Somestring"))          //Method 1
MyString == "Somestring"                //Method 2
String.Equals("Somestring", MyString);  //Method 3 (static String.Equals method) - better

where MyString is a variable that comes from somewhere else in the code.

Background info and to summerize:

In Java using == to compare strings should not be used. I mention this in case you need to use both languages and also to let you know that using == can also be replaced with something better in C#.

In C# there's no practical difference for comparing strings using Method 1 or Method 2 as long as both are of type string. However, if one is null, one is of another type (like an integer), or one represents an object that has a different reference, then, as the initial question shows, you may experience that comparing the content for equality may not return what you expect.

Suggested solution:

Because using == is not exactly the same as using .Equals when comparing things, you can use the static String.Equals method instead. This way, if the two sides are not the same type you will still compare the content and if one is null, you will avoid the exception.

   bool areEqual = String.Equals("Somestring", MyString);  

It is a little more to write, but in my opinion, safer to use.

Here is some info copied from Microsoft:

public static bool Equals (string a, string b);

Parameters

a String

The first string to compare, or null.

b String

The second string to compare, or null.

Returns Boolean

true if the value of a is the same as the value of b; otherwise, false. If both a and b are null, the method returns true.

How do I use Access-Control-Allow-Origin? Does it just go in between the html head tags?

If you use Java and spring MVC you just need to add the following annotation to your method returning your page :

@CrossOrigin(origins = "*")

"*" is to allow your page to be accessible from anywhere. See https://developer.mozilla.org/fr/docs/Web/HTTP/Headers/Access-Control-Allow-Origin for more details about that.

Exporting data In SQL Server as INSERT INTO

You could also check out the "Data Scripter Add-In" for SQL Server Management Studio 2008 from:

http://www.mssql-vehicle-data.com/SSMS


Their features list:

  • It was developed on SSMS 2008 and is not supported on the 2005 version at this time (soon!)

  • Export data quickly to T-SQL for MSSQL and MySQL syntax

  • CSV, TXT, XML are also supported! Harness the full potential, power, and speed that SQL has to offer.

  • Don't wait for Access or Excel to do scripting work for you that could take several minutes to do -- let SQL Server do it for you and take all the guess work out of exporting your data!

  • Customize your data output for rapid backups, DDL manipulation, and more...

  • Change table names and database schemas to your needs, quickly and efficiently

  • Export column names or simply generate data without the names.

  • You can chose individual columns to script.

  • You can chose sub-sets of data (WHERE clause).

  • You can chose ordering of data (ORDER BY clause).

  • Great backup utility for those grungy database debugging operations that require data manipulation. Don't lose data while experimenting. Manipulate data on the fly!

How to execute a bash command stored as a string with quotes and asterisk

Use an array, not a string, as given as guidance in BashFAQ #50.

Using a string is extremely bad security practice: Consider the case where password (or a where clause in the query, or any other component) is user-provided; you don't want to eval a password containing $(rm -rf .)!


Just Running A Local Command

cmd=( mysql AMORE -u username -ppassword -h localhost -e "SELECT  host  FROM amoreconfig" )
"${cmd[@]}"

Printing Your Command Unambiguously

cmd=( mysql AMORE -u username -ppassword -h localhost -e "SELECT  host  FROM amoreconfig" )
printf 'Proposing to run: '
printf '%q ' "${cmd[@]}"
printf '\n'

Running Your Command Over SSH (Method 1: Using Stdin)

cmd=( mysql AMORE -u username -ppassword -h localhost -e "SELECT  host  FROM amoreconfig" )
printf -v cmd_str '%q ' "${cmd[@]}"
ssh other_host 'bash -s' <<<"$cmd_str"

Running Your Command Over SSH (Method 2: Command Line)

cmd=( mysql AMORE -u username -ppassword -h localhost -e "SELECT  host  FROM amoreconfig" )
printf -v cmd_str '%q ' "${cmd[@]}"
ssh other_host "bash -c $cmd_str"

How do I list loaded plugins in Vim?

If you use vim-plug (Plug), " A minimalist Vim plugin manager.":

:PlugStatus

That will not only list your plugins but check their status.

Is there a short cut for going back to the beginning of a file by vi editor?

Well, you have [[ and ]] to go to the start and end of file. This works in vi.

How to use unicode characters in Windows command line?

A quick decision for .bat files if you computer displays your path/file name correct when you typing it in DOS-window:

  1. copy con temp.txt [press Enter]
  2. Type the path/file name [press Enter]
  3. Press Ctrl-Z [press Enter]

This way you create a .txt file - temp.txt. Open it in Notepad, copy the text (don't worry it will look unreadable) and paste it in your .bat file. Executing the .bat created this way in DOS-window worked for m? (Cyrillic, Bulgarian).

upstream sent too big header while reading response header from upstream

Plesk instructions

I combined the top two answers here

In Plesk 12, I had nginx running as a reverse proxy (which I think is the default). So the current top answer doesn't work as nginx is also being run as a proxy.

I went to Subscriptions | [subscription domain] | Websites & Domains (tab) | [Virtual Host domain] | Web Server Settings.

Then at the bottom of that page you can set the Additional nginx directives which I set to be a combination of the top two answers here:

fastcgi_buffers         16  16k;
fastcgi_buffer_size         32k;
proxy_buffer_size          128k;
proxy_buffers            4 256k;
proxy_busy_buffers_size    256k;

Check if a variable exists in a list in Bash

Matvey is right, but you should quote $x and consider any kind of "spaces" (e.g. new line) with

[[ $list =~ (^|[[:space:]])"$x"($|[[:space:]]) ]] && echo 'yes' || echo 'no' 

so, i.e.

# list_include_item "10 11 12" "2"
function list_include_item {
  local list="$1"
  local item="$2"
  if [[ $list =~ (^|[[:space:]])"$item"($|[[:space:]]) ]] ; then
    # yes, list include item
    result=0
  else
    result=1
  fi
  return $result
}

end then

`list_include_item "10 11 12" "12"`  && echo "yes" || echo "no"

or

if `list_include_item "10 11 12" "1"` ; then
  echo "yes"
else 
  echo "no"
fi

Note that you must use "" in case of variables:

`list_include_item "$my_list" "$my_item"`  && echo "yes" || echo "no"

Execute bash script from URL

For bash, Bourne shell and fish:

curl -s http://server/path/script.sh | bash -s arg1 arg2

Flag "-s" makes shell read from stdin.

ERROR 2003 (HY000): Can't connect to MySQL server (111)

if the system you use is CentOS/RedHat, and rpm is the way you install MySQL, there is no my.cnf in /etc/ folder, you could use: #whereis mysql #cd /usr/share/mysql/ cp -f /usr/share/mysql/my-medium.cnf /etc/my.cnf

How to create a BKS (BouncyCastle) format Java Keystore that contains a client certificate chain

Not sure you resolved this issue or not, but this is how I do it and it works on Android:

  1. Use openssl to merge client's cert(cert must be signed by a CA that accepted by server) and private key into a PCKS12 format key pair: openssl pkcs12 -export -in clientcert.pem -inkey clientkey.pem -out client.p12
  2. You may need patch your JRE to umlimited strength encryption depends on your key strength: copy the jar files fromJCE 5.0 unlimited strength Jurisdiction Policy FIles and override those in your JRE (eg.C:\Program Files\Java\jre6\lib\security)
  3. Use Portecle tool mentioned above and create a new keystore with BKS format
  4. Import PCKS12 key pair generated in step 1 and save it as BKS keystore. This keystore works with Android client authentication.
  5. If you need to do certificate chain, you can use this IBM tool:KeyMan to merge client's PCKS12 key pair with CA cert. But it only generate JKS keystore, so you again need Protecle to convert it to BKS format.

How to add plus one (+1) to a SQL Server column in a SQL Query

"UPDATE TableName SET TableField = TableField + 1 WHERE SomeFilterField = @ParameterID"

Microsoft Visual C++ 14.0 is required (Unable to find vcvarsall.bat)

Just had the same issue while using the latest Python 3.6. With Windows OS 10 Home Edition and 64 Bit Operation System

Steps to solve this issue :

  1. Uninstall any versions of Visual studio you have had, through Control Panel
  2. Install Visual Studio 2015 and chose the default option that will install Visual C++ 14.0 on its own
  3. You can use Pycharm for installing scrapy ->Project->Project Interpreter->+ (install scrapy)
  4. check scrapy in REPL and pycharm by import , you should not see any errors

How many values can be represented with n bits?

Without wanting to give you the answer here is the logic.

You have 2 possible values in each digit. you have 9 of them.

like in base 10 where you have 10 different values by digit say you have 2 of them (which makes from 0 to 99) : 0 to 99 makes 100 numbers. if you do the calcul you have an exponential function

base^numberOfDigits:
10^2 = 100 ;
2^9 = 512

Is it possible to use JavaScript to change the meta-tags of the page?

var metaTag = document.getElementsByTagName('meta');
for (var i=0; i < metaTag.length; i++) {
    if (metaTag[i].getAttribute("http-equiv")=='refresh')
        metaTag[i].content = '666';
    if (metaTag[i].getAttribute("name")=='Keywords')
        metaTag[i].content = 'js, solver';
}

How do I Sort a Multidimensional Array in PHP

With usort. Here's a generic solution, that you can use for different columns:

class TableSorter {
  protected $column;
  function __construct($column) {
    $this->column = $column;
  }
  function sort($table) {
    usort($table, array($this, 'compare'));
    return $table;
  }
  function compare($a, $b) {
    if ($a[$this->column] == $b[$this->column]) {
      return 0;
    }
    return ($a[$this->column] < $b[$this->column]) ? -1 : 1;
  }
}

To sort by first column:

$sorter = new TableSorter(0); // sort by first column
$mdarray = $sorter->sort($mdarray);

What are the best practices for SQLite on Android?

Inserts, updates, deletes and reads are generally OK from multiple threads, but Brad's answer is not correct. You have to be careful with how you create your connections and use them. There are situations where your update calls will fail, even if your database doesn't get corrupted.

The basic answer.

The SqliteOpenHelper object holds on to one database connection. It appears to offer you a read and write connection, but it really doesn't. Call the read-only, and you'll get the write database connection regardless.

So, one helper instance, one db connection. Even if you use it from multiple threads, one connection at a time. The SqliteDatabase object uses java locks to keep access serialized. So, if 100 threads have one db instance, calls to the actual on-disk database are serialized.

So, one helper, one db connection, which is serialized in java code. One thread, 1000 threads, if you use one helper instance shared between them, all of your db access code is serial. And life is good (ish).

If you try to write to the database from actual distinct connections at the same time, one will fail. It will not wait till the first is done and then write. It will simply not write your change. Worse, if you don’t call the right version of insert/update on the SQLiteDatabase, you won’t get an exception. You’ll just get a message in your LogCat, and that will be it.

So, multiple threads? Use one helper. Period. If you KNOW only one thread will be writing, you MAY be able to use multiple connections, and your reads will be faster, but buyer beware. I haven't tested that much.

Here's a blog post with far more detail and an example app.

Gray and I are actually wrapping up an ORM tool, based off of his Ormlite, that works natively with Android database implementations, and follows the safe creation/calling structure I describe in the blog post. That should be out very soon. Take a look.


In the meantime, there is a follow up blog post:

Also checkout the fork by 2point0 of the previously mentioned locking example:

how to write an array to a file Java

If you're okay with Apache commons lib

outputWriter.write(ArrayUtils.join(array, ","));

Node.js: for each … in not working

for (var i in conf) {
  val = conf[i];
  console.log(val.path);
}

How can I get the current date and time in UTC or GMT in Java?

If you want a Date object with fields adjusted for UTC you can do it like this with Joda Time:

import org.joda.time.DateTimeZone;
import java.util.Date;

...

Date local = new Date();
System.out.println("Local: " + local);
DateTimeZone zone = DateTimeZone.getDefault();
long utc = zone.convertLocalToUTC(local.getTime(), false);
System.out.println("UTC: " + new Date(utc));

How to display with n decimal places in Matlab

i use like tim say sprintf('%0.6f', x), it's a string then i change it to number by using command str2double(x).

JQuery, setTimeout not working

SetTimeout is used to make your set of code to execute after a specified time period so for your requirements its better to use setInterval because that will call your function every time at a specified time interval.

What is Ad Hoc Query?

An Ad-Hoc Query is a query that cannot be determined prior to the moment the query is issued. It is created in order to get information when need arises and it consists of dynamically constructed SQL which is usually constructed by desktop-resident query tools.

Check: http://www.learn.geekinterview.com/data-warehouse/dw-basics/what-is-an-ad-hoc-query.html

Remove space above and below <p> tag HTML

Look here: http://www.w3schools.com/tags/tag_p.asp

The p element automatically creates some space before and after itself. The space is automatically applied by the browser, or you can specify it in a style sheet.

you could remove the extra space by using css

p {
   margin: 0px;
   padding: 0px;
}

or use the element <span> which has no default margins and is an inline element.

"use database_name" command in PostgreSQL

In pgAdmin you can also use

SET search_path TO your_db_name;

Common xlabel/ylabel for matplotlib subplots

Update:

This feature is now part of the proplot matplotlib package that I recently released on pypi. By default, when you make figures, the labels are "shared" between axes.


Original answer:

I discovered a more robust method:

If you know the bottom and top kwargs that went into a GridSpec initialization, or you otherwise know the edges positions of your axes in Figure coordinates, you can also specify the ylabel position in Figure coordinates with some fancy "transform" magic. For example:

import matplotlib.transforms as mtransforms
bottom, top = .1, .9
f, a = plt.subplots(nrows=2, ncols=1, bottom=bottom, top=top)
avepos = (bottom+top)/2
a[0].yaxis.label.set_transform(mtransforms.blended_transform_factory(
       mtransforms.IdentityTransform(), f.transFigure # specify x, y transform
       )) # changed from default blend (IdentityTransform(), a[0].transAxes)
a[0].yaxis.label.set_position((0, avepos))
a[0].set_ylabel('Hello, world!')

...and you should see that the label still appropriately adjusts left-right to keep from overlapping with ticklabels, just like normal -- but now it will adjust to be always exactly between the desired subplots.

Furthermore, if you don't even use set_position, the ylabel will show up by default exactly halfway up the figure. I'm guessing this is because when the label is finally drawn, matplotlib uses 0.5 for the y-coordinate without checking whether the underlying coordinate transform has changed.

Can you put two conditions in an xslt test attribute?

Not quite, the AND has to be lower-case.

<xsl:when test="4 &lt; 5 and 1 &lt; 2">
<!-- do something -->
</xsl:when>

How to get MAC address of your machine using a C program?

This is a Bash line that prints all available mac addresses, except the loopback:

for x in `ls /sys/class/net |grep -v lo`; do cat /sys/class/net/$x/address; done

Can be executed from a C program.

set the iframe height automatically

Solomon's answer about bootstrap inspired me to add the CSS the bootstrap solution uses, which works really well for me.

.iframe-embed {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    height: 100%;
    width: 100%;
    border: 0;
}
.iframe-embed-wrapper {
    position: relative;
    display: block;
    height: 0;
    padding: 0;
    overflow: hidden;
}
.iframe-embed-responsive-16by9 {
    padding-bottom: 56.25%;
}
<div class="iframe-embed-wrapper iframe-embed-responsive-16by9">
    <iframe class="iframe-embed" src="vid.mp4"></iframe>
</div>

Is there a foreach loop in Go?

I have jus implement this library:https://github.com/jose78/go-collection. This is an example about how to use the Foreach loop:

package main

import (
    "fmt"

    col "github.com/jose78/go-collection/collections"
)

type user struct {
    name string
    age  int
    id   int
}

func main() {
    newList := col.ListType{user{"Alvaro", 6, 1}, user{"Sofia", 3, 2}}
    newList = append(newList, user{"Mon", 0, 3})

    newList.Foreach(simpleLoop)
    
    if err := newList.Foreach(simpleLoopWithError); err != nil{
        fmt.Printf("This error >>> %v <<< was produced", err )  
    }
}

var simpleLoop col.FnForeachList = func(mapper interface{}, index int) {
    fmt.Printf("%d.- item:%v\n", index, mapper)
}


var simpleLoopWithError col.FnForeachList = func(mapper interface{}, index int) {
    if index > 1{
        panic(fmt.Sprintf("Error produced with index == %d\n", index))
    }
    fmt.Printf("%d.- item:%v\n", index, mapper)
}

The result of this execution should be:

0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
2.- item:{Mon 0 3}
0.- item:{Alvaro 6 1}
1.- item:{Sofia 3 2}
Recovered in f Error produced with index == 2

ERROR: Error produced with index == 2
This error >>> Error produced with index == 2
 <<< was produced

Try this code in playGrounD

How to change the default background color white to something else in twitter bootstrap

You can simply add this line into your bootstrap_and_overides.css.less file

body { background: #000000 !important;}

that's it

How to remove all characters after a specific character in python?

If you want to remove everything after the last occurrence of separator in a string I find this works well:

<separator>.join(string_to_split.split(<separator>)[:-1])

For example, if string_to_split is a path like root/location/child/too_far.exe and you only want the folder path, you can split by "/".join(string_to_split.split("/")[:-1]) and you'll get root/location/child

Saving a Excel File into .txt format without quotes

The answer from this question provided the answer to this question much more simply.

Write is a special statement designed to generate machine-readable files that are later consumed with Input.

Use Print to avoid any fiddling with data.

Thank you user GSerg

Capture iOS Simulator video for App Preview

From Xcode 9 and on you can take screenshot or record Video using simctl binary that you can find it here:

/Applications/Xcode.app/Contents/Developer/usr/bin/simctl

You can use it with xcrun to command the simulator in the command line.

  1. For taking screenshot run this in command line:

    xcrun simctl io booted screenshot
    
  2. For recording video on the simulator using command line:

    xcrun simctl io booted recordVideo fileName.videoType(e.g mp4/mov)
    

Note: You can use this command in any directory of your choice. The file will be saved in that directory.

C multi-line macro: do/while(0) vs scope block

Andrey Tarasevich provides the following explanation:

  1. On Google Groups
  2. On bytes.com

[Minor changes to formatting made. Parenthetical annotations added in square brackets []].

The whole idea of using 'do/while' version is to make a macro which will expand into a regular statement, not into a compound statement. This is done in order to make the use of function-style macros uniform with the use of ordinary functions in all contexts.

Consider the following code sketch:

if (<condition>)
  foo(a);
else
  bar(a);

where foo and bar are ordinary functions. Now imagine that you'd like to replace function foo with a macro of the above nature [named CALL_FUNCS]:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

Now, if your macro is defined in accordance with the second approach (just { and }) the code will no longer compile, because the 'true' branch of if is now represented by a compound statement. And when you put a ; after this compound statement, you finished the whole if statement, thus orphaning the else branch (hence the compilation error).

One way to correct this problem is to remember not to put ; after macro "invocations":

if (<condition>)
  CALL_FUNCS(a)
else
  bar(a);

This will compile and work as expected, but this is not uniform. The more elegant solution is to make sure that macro expand into a regular statement, not into a compound one. One way to achieve that is to define the macro as follows:

#define CALL_FUNCS(x) \
do { \
  func1(x); \
  func2(x); \
  func3(x); \
} while (0)

Now this code:

if (<condition>)
  CALL_FUNCS(a);
else
  bar(a);

will compile without any problems.

However, note the small but important difference between my definition of CALL_FUNCS and the first version in your message. I didn't put a ; after } while (0). Putting a ; at the end of that definition would immediately defeat the entire point of using 'do/while' and make that macro pretty much equivalent to the compound-statement version.

I don't know why the author of the code you quoted in your original message put this ; after while (0). In this form both variants are equivalent. The whole idea behind using 'do/while' version is not to include this final ; into the macro (for the reasons that I explained above).

Best way of invoking getter by reflection

I think this should point you towards the right direction:

import java.beans.*

for (PropertyDescriptor pd : Introspector.getBeanInfo(Foo.class).getPropertyDescriptors()) {
  if (pd.getReadMethod() != null && !"class".equals(pd.getName()))
    System.out.println(pd.getReadMethod().invoke(foo));
}

Note that you could create BeanInfo or PropertyDescriptor instances yourself, i.e. without using Introspector. However, Introspector does some caching internally which is normally a Good Thing (tm). If you're happy without a cache, you can even go for

// TODO check for non-existing readMethod
Object value = new PropertyDescriptor("name", Person.class).getReadMethod().invoke(person);

However, there are a lot of libraries that extend and simplify the java.beans API. Commons BeanUtils is a well known example. There, you'd simply do:

Object value = PropertyUtils.getProperty(person, "name");

BeanUtils comes with other handy stuff. i.e. on-the-fly value conversion (object to string, string to object) to simplify setting properties from user input.

How can I close a dropdown on click outside?

If you're doing this on iOS, use the touchstart event as well:

As of Angular 4, the HostListener decorate is the preferred way to do this

import { Component, OnInit, HostListener, ElementRef } from '@angular/core';
...
@Component({...})
export class MyComponent implement OnInit {

  constructor(private eRef: ElementRef){}

  @HostListener('document:click', ['$event'])
  @HostListener('document:touchstart', ['$event'])
  handleOutsideClick(event) {
    // Some kind of logic to exclude clicks in Component.
    // This example is borrowed Kamil's answer
    if (!this.eRef.nativeElement.contains(event.target) {
      doSomethingCool();
    }
  }

}

How can I maintain fragment state when added to the back stack?

Perfect solution that find old fragment in stack and load it if exist in stack.

/**
     * replace or add fragment to the container
     *
     * @param fragment pass android.support.v4.app.Fragment
     * @param bundle pass your extra bundle if any
     * @param popBackStack if true it will clear back stack
     * @param findInStack if true it will load old fragment if found
     */
    public void replaceFragment(Fragment fragment, @Nullable Bundle bundle, boolean popBackStack, boolean findInStack) {
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        String tag = fragment.getClass().getName();
        Fragment parentFragment;
        if (findInStack && fm.findFragmentByTag(tag) != null) {
            parentFragment = fm.findFragmentByTag(tag);
        } else {
            parentFragment = fragment;
        }
        // if user passes the @bundle in not null, then can be added to the fragment
        if (bundle != null)
            parentFragment.setArguments(bundle);
        else parentFragment.setArguments(null);
        // this is for the very first fragment not to be added into the back stack.
        if (popBackStack) {
            fm.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
        } else {
            ft.addToBackStack(parentFragment.getClass().getName() + "");
        }
        ft.replace(R.id.contenedor_principal, parentFragment, tag);
        ft.commit();
        fm.executePendingTransactions();
    }

use it like

Fragment f = new YourFragment();
replaceFragment(f, null, boolean true, true); 

Center the nav in Twitter Bootstrap

You can make the .navbar fixed width, then set it's left and right margin to auto.

Demo

.navbar{
    width: 80%;
    margin: 0 auto;
}?

Difference between \b and \B in regex

\b is a zero-width word boundary. Specifically:

Matches at the position between a word character (anything matched by \w) and a non-word character (anything matched by [^\w] or \W) as well as at the start and/or end of the string if the first and/or last characters in the string are word characters.

Example: .\b matches c in abc

\B is a zero-width non-word boundary. Specifically:

Matches at the position between two word characters (i.e the position between \w\w) as well as at the position between two non-word characters (i.e. \W\W).

Example: \B.\B matches b in abc

See regular-expressions.info for more great regex info

How to delete columns that contain ONLY NAs?

Here is a dplyr solution:

df %>% select_if(~sum(!is.na(.)) > 0)

Update: The summarise_if() function is superseded as of dplyr 1.0. Here are two other solutions that use the where() tidyselect function:

df %>% 
  select(
    where(
      ~sum(!is.na(.x)) > 0
    )
  )
df %>% 
  select(
    where(
      ~!all(is.na(.x))
    )
  )

Not equal to != and !== in PHP

You can find the info here: http://www.php.net/manual/en/language.operators.comparison.php

It's scarce because it wasn't added until PHP4. What you have is fine though, if you know there may be a type difference then it's a much better comparison, since it's testing value and type in the comparison, not just value.

Uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)

I have faced this problem in many occassions when I try to start an old rails 2.3.5 project after having worked with rails 3>. In my case to solve the problem, I must do a rubygems update to version 1.4.2, this is:

sudo gem update --system 1.4.2

Centering the image in Bootstrap

.img-responsive {
     margin: 0 auto;
 }

you can write like above code in your document so no need to add one another class in image tag.

HashMap - getting First Key value

Note that you should note that your logic flow must never rely on accessing the HashMap elements in some order, simply put because HashMaps are not ordered Collections and that is not what they are aimed to do. (You can read more about odered and sorter collections in this post).

Back to the post, you already did half the job by loading the first element key:

Object myKey = statusName.keySet().toArray()[0];

Just call map.get(key) to get the respective value:

Object myValue = statusName.get(myKey);

Improving bulk insert performance in Entity framework

There is opportunity for several improvements (if you are using DbContext):

Set:

yourContext.Configuration.AutoDetectChangesEnabled = false;
yourContext.Configuration.ValidateOnSaveEnabled = false;

Do SaveChanges() in packages of 100 inserts... or you can try with packages of 1000 items and see the changes in performance.

Since during all this inserts, the context is the same and it is getting bigger, you can rebuild your context object every 1000 inserts. var yourContext = new YourContext(); I think this is the big gain.

Doing this improvements in an importing data process of mine, took it from 7 minutes to 6 seconds.

The actual numbers... could not be 100 or 1000 in your case... try it and tweak it.

How to select specific form element in jQuery?

although it is invalid html but you can use selector context to limit your selector in your case it would be like :

$("input[name='name']" , "#form2").val("Hello World! ");

http://api.jquery.com/jquery/#selector-context

Eclipse: stop code from running (java)

The easiest way to do this is to click on the Terminate button(red square) in the console:

enter image description here

C# loop - break vs. continue

To break completely out of a foreach loop, break is used;

To go to the next iteration in the loop, continue is used;

Break is useful if you’re looping through a collection of Objects (like Rows in a Datatable) and you are searching for a particular match, when you find that match, there’s no need to continue through the remaining rows, so you want to break out.

Continue is useful when you have accomplished what you need to in side a loop iteration. You’ll normally have continue after an if.

PHP mail not working for some reason

"Just because you send an email doesn't mean it will arrive."

Sending mail is Serious Business - e.g. the domain you're using as your "From:" address may be configured to reject e-mails from your webserver. For a longer overview (and some tips what to check), see http://www.codinghorror.com/blog/2010/04/so-youd-like-to-send-some-email-through-code.html

Google Chrome default opening position and size

First, close all instances of Google Chrome. There should be no instances of chrome.exe running in the Windows Task Manager. Then

  • Go to %LOCALAPPDATA%\Google\Chrome\User Data\Default\.
  • Open the file "Preferences" in a text editor like Notepad.
  • First, resave the file to something like "Preference - Old" without any extension (i.e. no .txt). This will serve as a backup, should something go wrong.
  • Look for a section called "browser." Inside that section, you should find a subsection called window_placement. Under window_placement you will see things like "bottom", "left", "right", etc. with numbers after them.

You will need to play around with these numbers to get your desired window size and placement. When finished, save this file with the name "Preferences" again with no extension. This will overwrite the existing Preferences file. Open Chrome and see how you did. If you're not satisfied with the size and placement, close Chrome and change the numbers in the Preferences file until you get what you want.

What does "int 0x80" mean in assembly code?

The "int" instruction causes an interrupt.

What's an interrupt?

Simple Answer: An interrupt, put simply, is an event that interrupts the CPU, and tells it to run a specific task.

Detailed Answer:

The CPU has a table of Interrupt Service Routines (or ISRs) stored in memory. In Real (16-bit) Mode, this is stored as the IVT, or Interrupt Vector Table. The IVT is typically located at 0x0000:0x0000 (physical address 0x00000), and it is a series of segment-offset addresses that point to the ISRs. The OS may replace the pre-existing IVT entries with its own ISRs.

(Note: The IVT's size is fixed at 1024 (0x400) bytes.)

In Protected (32-bit) Mode, the CPU uses an IDT. The IDT is a variable-length structure that consists of descriptors (otherwise known as gates), which tell the CPU about the interrupt handlers. The structure of these descriptors is much more complex than the IVT's simple segment-offset entries; here it is:

bytes 0, 1: Lower 16 bits of the ISR's address.
bytes 2, 3: A code segment selector (in the GDT/LDT)
byte 4: Zero.
byte 5: A type field consisting of several bitfields.
    bit 0:  P (Present): 0 for unused interrupts, 1 for used interrupts.*
    bits 1, 2: DPL (Descriptor Privilege Level): The privilege level the descriptor (bytes 2, 3) must have.
    bit 3: S (Storage Segment): Is 0 for interrupt and trap gates. Otherwise, is one. 
    bits 4, 5, 6, 7: GateType:
        0101: 32 bit task gate
        0110: 16-bit interrupt gate
        0111: 16-bit trap gate
        1110: 32-bit interrupt gate
        1111: 32-bit trap gate
 

*The IDT may be of variable size, but it must be sequential, i.e. if you declare your IDT to be from 0x00 to 0x50, you must have every interrupt from 0x00 to 0x50. The OS does not necessarily use all of them, so the Present bit allows the CPU to properly handle interrupts the OS does not intend to handle.

When an interrupt occurs (either by an external trigger (e.g. a hardware device) in an IRQ, or by the int instruction from a program), the CPU pushes EFLAGS, then CS, and then EIP. (These are automatically restored by iret, the interrupt return instruction.) The OS usually stores more information about the state of the machine, handles the interrupt, restores the machine state, and continues on.

In many *NIX OSes (including Linux), system calls are interrupt based. The program puts the arguments to the system call in the registers (EAX, EBX, ECX, EDX, etc..), and calls interrupt 0x80. The kernel has already set the IDT to contain an interrupt handler on 0x80, which is called when it receives interrupt 0x80. The kernel then reads the arguments and invokes a kernel function accordingly. It may store a return in EAX/EBX. System calls have largely been replaced by the sysenter and sysexit (or syscall and sysret on AMD) instructions, which allow for faster entry into ring 0.

This interrupt could have a different meaning in a different OS. Be sure to check its documentation.

Jquery Setting Value of Input Field

Put your jQuery function in

$(document).ready(function(){

});

It's surely solved.

How to pass password to scp?

Nobody mentioned it, but Putty scp (pscp) has a -pw option for password.

Documentation can be found here: https://the.earth.li/~sgtatham/putty/0.67/htmldoc/Chapter5.html#pscp

How to clear the interpreter console?

Magic strings are mentioned above - I believe they come from the terminfo database:

http://www.google.com/?q=x#q=terminfo

http://www.google.com/?q=x#q=tput+command+in+unix

$ tput clear| od -t x1z 0000000 1b 5b 48 1b 5b 32 4a >.[H.[2J< 0000007

How to left align a fixed width string?

Use -50% instead of +50% They will be aligned to left..

Select distinct values from a large DataTable column

Sorry to post answer for very old thread. my answer may help other in future.

string[] TobeDistinct = {"Name","City","State"};
DataTable dtDistinct = GetDistinctRecords(DTwithDuplicate, TobeDistinct);

    //Following function will return Distinct records for Name, City and State column.
    public static DataTable GetDistinctRecords(DataTable dt, string[] Columns)
       {
           DataTable dtUniqRecords = new DataTable();
           dtUniqRecords = dt.DefaultView.ToTable(true, Columns);
           return dtUniqRecords;
       }

Vim autocomplete for Python

As pointed out by in the comments, this answers is outdated. youcompleteme now supports python3 and jedi-vim no longer breaks the undo history.

Original answer below.


AFAIK there are three options, each with its disadvantages:

  1. youcompleteme: unfriendly to install, but works nice if you manage to get it working. However python3 is not supported.
  2. jedi-vim: coolest name, but breaks your undo history.
  3. python-mode does a lot more the autocomplete: folding, syntax checking, highlighting. Personally I prefer scripts that do 1 thing well, as they are easier to manage (and replace). Differently from the two other options, it uses rope instead of jedi for autocompletion.

Python 3 and undo history (gundo!) are a must for me, so options 1 and 2 are out.

PHP checkbox set to check based on database value

Use checked="checked" attribute if you want your checkbox to be checked.

How to run a command as a specific user in an init script?

I usually do it the way that you are doing it (i.e. sudo -u username command). But, there is also the 'djb' way to run a daemon with privileges of another user. See: http://thedjbway.b0llix.net/daemontools/uidgid.html

Change color of Button when Mouse is over

<Button Background="#FF4148" BorderThickness="0" BorderBrush="Transparent">
     <Border HorizontalAlignment="Right" BorderBrush="#FF6A6A" BorderThickness="0>
     <Border.Style>
         <Style TargetType="Border">
             <Style.Triggers>
                 <Trigger Property="IsMouseOver" Value="True">
                     <Setter Property="Background" Value="#FF6A6A" />
                 </Trigger>
             </Style.Triggers>
         </Style>
      </Border.Style>
      <StackPanel Orientation="Horizontal">
           <Image  RenderOptions.BitmapScalingMode="HighQuality"   Source="//ImageName.png"   />
      </StackPanel>
      </Border>
  </Button>

Setting up PostgreSQL ODBC on Windows

As I see PostgreSQL installer doesn't include 64 bit version of ODBC driver, which is necessary in your case. Download psqlodbc_09_00_0310-x64.zip and install it instead. I checked that on Win 7 64 bit and PostgreSQL 9.0.4 64 bit and it looks ok:

enter image description here

Test connection:

enter image description here

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;

What is REST? Slightly confused

It stands for Representational State Transfer and it can mean a lot of things, but usually when you are talking about APIs and applications, you are talking about REST as a way to do web services or get programs to talk over the web.

REST is basically a way of communicating between systems and does much of what SOAP RPC was designed to do, but while SOAP generally makes a connection, authenticates and then does stuff over that connection, REST works pretty much the same way that that the web works. You have a URL and when you request that URL you get something back. This is where things start getting confusing because people describe the web as a the largest REST application and while this is technically correct it doesn't really help explain what it is.

In a nutshell, REST allows you to get two applications talking over the Internet using tools that are similar to what a web browser uses. This is much simpler than SOAP and a lot of what REST does is says, "Hey, things don't have to be so complex."

Worth reading:

Adding values to Arraylist

in the first you don't define the type that will be held and linked within your arraylist construct

this is the preferred method to do so, you define the type of list and the ide will handle the rest

in the third one you will better just define List for shorter code

How to get access token from FB.login method in javascript SDK

response.session doesn't work anymore because response.authResponse is the new way to access the response content after the oauth migration.
Check this for details: SDKs & Tools › JavaScript SDK › FB.login

How do you convert a C++ string to an int?

Perhaps I am misunderstanding the question, by why exactly would you not want to use atoi? I see no point in reinventing the wheel.

Am I just missing the point here?

Why do we use arrays instead of other data structures?

A way to look at advantages of arrays is to see where is the O(1) access capability of arrays is required and hence capitalized:

  1. In Look-up tables of your application (a static array for accessing certain categorical responses)

  2. Memoization (already computed complex function results, so that you don't calculate the function value again, say log x)

  3. High Speed computer vision applications requiring image processing (https://en.wikipedia.org/wiki/Lookup_table#Lookup_tables_in_image_processing)

PHP Fatal error: Call to undefined function mssql_connect()

php.ini probably needs to read: extension=ext\php_sqlsrv_53_nts.dll

Or move the file to same directory as the php executable. This is what I did to my php5 install this week to get odbc_pdo working. :P

Additionally, that doesn't look like proper phpinfo() output. If you make a file with contents
<? phpinfo(); ?> and visit that page, the HTML output should show several sections, including one with loaded modules. (Edited to add: like shown in the screenshot of the above accepted answer)

Comparing strings by their alphabetical order

String.compareTo might or might not be what you need.

Take a look at this link if you need localized ordering of strings.

Get Unix timestamp with C++

Windows uses a different epoch and time units: see Convert Windows Filetime to second in Unix/Linux

What std::time() returns on Windows is (as yet) unknown to me (;-))

Difference between Hive internal tables and external tables?

To answer you Question :

For External Tables, Hive stores the data in the LOCATION specified during creation of the table(generally not in warehouse directory). If the external table is dropped, then the table metadata is deleted but not the data.

For Internal tables, Hive stores data into its warehouse directory. If the table is dropped then both the table metadata and the data will be deleted.


For your reference,

Difference between Internal & External tables :

For External Tables -

  • External table stores files on the HDFS server but tables are not linked to the source file completely.

  • If you delete an external table the file still remains on the HDFS server.

    As an example if you create an external table called “table_test” in HIVE using HIVE-QL and link the table to file “file”, then deleting “table_test” from HIVE will not delete “file” from HDFS.

  • External table files are accessible to anyone who has access to HDFS file structure and therefore security needs to be managed at the HDFS file/folder level.

  • Meta data is maintained on master node, and deleting an external table from HIVE only deletes the metadata not the data/file.


For Internal Tables-

  • Stored in a directory based on settings in hive.metastore.warehouse.dir, by default internal tables are stored in the following directory “/user/hive/warehouse” you can change it by updating the location in the config file .
  • Deleting the table deletes the metadata and data from master-node and HDFS respectively.
  • Internal table file security is controlled solely via HIVE. Security needs to be managed within HIVE, probably at the schema level (depends on organization).

Hive may have internal or external tables, this is a choice that affects how data is loaded, controlled, and managed.

Use EXTERNAL tables when:

  • The data is also used outside of Hive. For example, the data files are read and processed by an existing program that doesn’t lock the files.
  • Data needs to remain in the underlying location even after a DROP TABLE. This can apply if you are pointing multiple schema (tables or views) at a single data set or if you are iterating through various possible schema.
  • Hive should not own data and control settings, directories, etc., you may have another program or process that will do those things.
  • You are not creating table based on existing table (AS SELECT).

Use INTERNAL tables when:

  • The data is temporary.
  • You want Hive to completely manage the life-cycle of the table and data.

Source :

HDInsight: Hive Internal and External Tables Intro

Internal & external tables in Hadoop- HIVE

How to select ALL children (in any level) from a parent in jQuery?

I think you could do:

$('#google_translate_element').find('*').each(function(){
    $(this).unbind('click');
});

but it would cause a lot of overhead

Delaying function in swift

Swift 3 and Above Version(s) for a delay of 10 seconds

    DispatchQueue.main.asyncAfter(deadline: .now() + 10) { [unowned self] in
        self.functionToCall()
    }

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

I managed to hit this error when simply creating a table! There was obviously no contention problem on a table that didn't yet exist. The CREATE TABLE statement contained a CONSTRAINT fk_name FOREIGN KEY clause referencing a well-populated table. I had to:

  • Remove the FOREIGN KEY clause from the CREATE TABLE statement
  • Create an INDEX on the FK column
  • Create the FK

How to downgrade python from 3.7 to 3.6

I just now downgraded my Python 3.9 to 3.6 because I wanted to use the librosa package but it does not support Python 3.9 still now.

Steps -

  • Go to python official website
  • Download the Python version which you want
  • Install in your machine normally

Run python3 --version in the terminal and it will show this version of Python.

Prevent any form of page refresh using jQuery/Javascript

No, there isn't.

I'm pretty sure there is no way to intercept a click on the refresh button from JS, and even if there was, JS can be turned off.

You should probably step back from your X (preventing refreshing) and find a different solution to Y (whatever that might be).

Decode UTF-8 with Javascript

This is what I found after a more specific Google search than just UTF-8 encode/decode. so for those who are looking for a converting library to convert between encodings, here you go.

https://github.com/inexorabletash/text-encoding

var uint8array = new TextEncoder().encode(str);
var str = new TextDecoder(encoding).decode(uint8array);

Paste from repo readme

All encodings from the Encoding specification are supported:

utf-8 ibm866 iso-8859-2 iso-8859-3 iso-8859-4 iso-8859-5 iso-8859-6 iso-8859-7 iso-8859-8 iso-8859-8-i iso-8859-10 iso-8859-13 iso-8859-14 iso-8859-15 iso-8859-16 koi8-r koi8-u macintosh windows-874 windows-1250 windows-1251 windows-1252 windows-1253 windows-1254 windows-1255 windows-1256 windows-1257 windows-1258 x-mac-cyrillic gb18030 hz-gb-2312 big5 euc-jp iso-2022-jp shift_jis euc-kr replacement utf-16be utf-16le x-user-defined

(Some encodings may be supported under other names, e.g. ascii, iso-8859-1, etc. See Encoding for additional labels for each encoding.)

how does int main() and void main() work

Neither main() or void main() are standard C. The former is allowed as it has an implicit int return value, making it the same as int main(). The purpose of main's return value is to return an exit status to the operating system.

In standard C, the only valid signatures for main are:

int main(void)

and

int main(int argc, char **argv)

The form you're using: int main() is an old style declaration that indicates main takes an unspecified number of arguments. Don't use it - choose one of those above.

What does this square bracket and parenthesis bracket notation mean [first1,last1)?

The concept of interval notation comes up in both Mathematics and Computer Science. The Mathematical notation [, ], (, ) denotes the domain (or range) of an interval.

  • The brackets [ and ] means:

    1. The number is included,
    2. This side of the interval is closed,
  • The parenthesis ( and ) means:

    1. The number is excluded,
    2. This side of the interval is open.

An interval with mixed states is called "half-open".

For example, the range of consecutive integers from 1 .. 10 (inclusive) would be notated as such:

  • [1,10]

Notice how the word inclusive was used. If we want to exclude the end point but "cover" the same range we need to move the end-point:

  • [1,11)

For both left and right edges of the interval there are actually 4 permutations:

(1,10) =   2,3,4,5,6,7,8,9       Set has  8 elements
(1,10] =   2,3,4,5,6,7,8,9,10    Set has  9 elements
[1,10) = 1,2,3,4,5,6,7,8,9       Set has  9 elements
[1,10] = 1,2,3,4,5,6,7,8,9,10    Set has 10 elements

How does this relate to Mathematics and Computer Science?

Array indexes tend to use a different offset depending on which field are you in:

  • Mathematics tends to be one-based.
  • Certain programming languages tends to be zero-based, such as C, C++, Javascript, Python, while other languages such as Mathematica, Fortran, Pascal are one-based.

These differences can lead to subtle fence post errors, aka, off-by-one bugs when implementing Mathematical algorithms such as for-loops.

Integers

If we have a set or array, say of the first few primes [ 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 ], Mathematicians would refer to the first element as the 1st absolute element. i.e. Using subscript notation to denote the index:

  • a1 = 2
  • a2 = 3
  • :
  • a10 = 29

Some programming languages, in contradistinction, would refer to the first element as the zero'th relative element.

  • a[0] = 2
  • a[1] = 3
  • :
  • a[9] = 29

Since the array indexes are in the range [0,N-1] then for clarity purposes it would be "nice" to keep the same numerical value for the range 0 .. N instead of adding textual noise such as a -1 bias.

For example, in C or JavaScript, to iterate over an array of N elements a programmer would write the common idiom of i = 0, i < N with the interval [0,N) instead of the slightly more verbose [0,N-1]:

_x000D_
_x000D_
function main() {_x000D_
    var output = "";_x000D_
    var a = [ 2, 3, 5, 7,  11, 13, 17, 19, 23, 29 ];_x000D_
    for( var i = 0; i < 10; i++ ) // [0,10)_x000D_
       output += "[" + i + "]: " + a[i] + "\n";_x000D_
_x000D_
    if (typeof window === 'undefined') // Node command line_x000D_
        console.log( output )_x000D_
    else_x000D_
        document.getElementById('output1').innerHTML = output;_x000D_
}
_x000D_
 <html>_x000D_
     <body onload="main();">_x000D_
         <pre id="output1"></pre>_x000D_
     </body>_x000D_
 </html>
_x000D_
_x000D_
_x000D_

Mathematicians, since they start counting at 1, would instead use the i = 1, i <= N nomenclature but now we need to correct the array offset in a zero-based language.

e.g.

_x000D_
_x000D_
function main() {_x000D_
    var output = "";_x000D_
    var a = [ 2, 3, 5, 7,  11, 13, 17, 19, 23, 29 ];_x000D_
    for( var i = 1; i <= 10; i++ ) // [1,10]_x000D_
       output += "[" + i + "]: " + a[i-1] + "\n";_x000D_
_x000D_
    if (typeof window === 'undefined') // Node command line_x000D_
        console.log( output )_x000D_
    else_x000D_
        document.getElementById( "output2" ).innerHTML = output;_x000D_
}
_x000D_
<html>_x000D_
    <body onload="main()";>_x000D_
        <pre id="output2"></pre>_x000D_
    </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Aside:

In programming languages that are 0-based you might need a kludge of a dummy zero'th element to use a Mathematical 1-based algorithm. e.g. Python Index Start

Floating-Point

Interval notation is also important for floating-point numbers to avoid subtle bugs.

When dealing with floating-point numbers especially in Computer Graphics (color conversion, computational geometry, animation easing/blending, etc.) often times normalized numbers are used. That is, numbers between 0.0 and 1.0.

It is important to know the edge cases if the endpoints are inclusive or exclusive:

  • (0,1) = 1e-M .. 0.999...
  • (0,1] = 1e-M .. 1.0
  • [0,1) = 0.0 .. 0.999...
  • [0,1] = 0.0 .. 1.0

Where M is some machine epsilon. This is why you might sometimes see const float EPSILON = 1e-# idiom in C code (such as 1e-6) for a 32-bit floating point number. This SO question Does EPSILON guarantee anything? has some preliminary details. For a more comprehensive answer see FLT_EPSILON and David Goldberg's What Every Computer Scientist Should Know About Floating-Point Arithmetic

Some implementations of a random number generator, random() may produce values in the range 0.0 .. 0.999... instead of the more convenient 0.0 .. 1.0. Proper comments in the code will document this as [0.0,1.0) or [0.0,1.0] so there is no ambiguity as to the usage.

Example:

  • You want to generate random() colors. You convert three floating-point values to unsigned 8-bit values to generate a 24-bit pixel with red, green, and blue channels respectively. Depending on the interval output by random() you may end up with near-white (254,254,254) or white (255,255,255).
     +--------+-----+
     |random()|Byte |
     |--------|-----|
     |0.999...| 254 | <-- error introduced
     |1.0     | 255 |
     +--------+-----+

For more details about floating-point precision and robustness with intervals see Christer Ericson's Real-Time Collision Detection, Chapter 11 Numerical Robustness, Section 11.3 Robust Floating-Point Usage.

JPA mapping: "QuerySyntaxException: foobar is not mapped..."

You have declared your Class as:

@Table( name = "foobar" )
public class FooBar {

You need to write the Class Name for the search.
from FooBar

WCF error: The caller was not authenticated by the service

Have you tried using basicHttpBinding instead of wsHttpBinding? If do not need any authentication and the Ws-* implementations are not required, you'd probably be better off with plain old basicHttpBinding. WsHttpBinding implements WS-Security for message security and authentication.

How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version

As answered elsewhere by several people, the Java program is being run on an older version of Java than the one it was compiled it for. It needs to be "crosscompiled" for backward compatibility. To put it another way, there is a mismatch between source and target Java versions.

Changing options in Eclipse menus don't answer the original poster, who said he/she is not using Eclipse. On OpenJDK javac version 1.7, you can crosscompile for 1.6 if you use parameters -source and -target, plus provide the rt.jar -file of the target version (that is, the older one) at compile time. If you actually install the 1.6 JRE, you can point to its installation (for example, /usr/lib/jvm/java-6-openjdk-i386/jre/lib/rt.jar on Ubuntu, /usr/jdk/jdk1.6.0_60/jre/lib/rt.jar on SunOS apparently. Sorry, I don't know where it is on a Windows system). Like so:

javac -source 1.6 -target 1.6 -bootclasspath /usr/lib/jvm/java-6-openjdk-i386/jre/lib/rt.jar HelloWorld.java

It looks like you can just download rt.jar from the Internet, and point to it. This is not too elegant though:

javac -source 1.6 -target 1.6 -bootclasspath ./rt.jar HelloWorld.java

How to catch a specific SqlException error?

With MS SQL 2008, we can list supported error messages in the table sys.messages

SELECT * FROM sys.messages

Is there any sizeof-like method in Java?

Try java.lang.Instrumentation.getObjectSize(Object). But please be aware that

It returns an implementation-specific approximation of the amount of storage consumed by the specified object. The result may include some or all of the object's overhead, and thus is useful for comparison within an implementation but not between implementations. The estimate may change during a single invocation of the JVM.

Getting text from td cells with jQuery

I would give your tds a specific class, e.g. data-cell, and then use something like this:

$("td.data-cell").each(function () {
    // 'this' is now the raw td DOM element
    var txt = $(this).html();
});

ASP.NET MVC Custom Error Handling Application_Error Global.asax?

I found a solution for ajax issue noted by Lion_cl.

global.asax:

protected void Application_Error()
    {           
        if (HttpContext.Current.Request.IsAjaxRequest())
        {
            HttpContext ctx = HttpContext.Current;
            ctx.Response.Clear();
            RequestContext rc = ((MvcHandler)ctx.CurrentHandler).RequestContext;
            rc.RouteData.Values["action"] = "AjaxGlobalError";

            // TODO: distinguish between 404 and other errors if needed
            rc.RouteData.Values["newActionName"] = "WrongRequest";

            rc.RouteData.Values["controller"] = "ErrorPages";
            IControllerFactory factory = ControllerBuilder.Current.GetControllerFactory();
            IController controller = factory.CreateController(rc, "ErrorPages");
            controller.Execute(rc);
            ctx.Server.ClearError();
        }
    }

ErrorPagesController

public ActionResult AjaxGlobalError(string newActionName)
    {
        return new AjaxRedirectResult(Url.Action(newActionName), this.ControllerContext);
    }

AjaxRedirectResult

public class AjaxRedirectResult : RedirectResult
{
    public AjaxRedirectResult(string url, ControllerContext controllerContext)
        : base(url)
    {
        ExecuteResult(controllerContext);
    }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context.RequestContext.HttpContext.Request.IsAjaxRequest())
        {
            JavaScriptResult result = new JavaScriptResult()
            {
                Script = "try{history.pushState(null,null,window.location.href);}catch(err){}window.location.replace('" + UrlHelper.GenerateContentUrl(this.Url, context.HttpContext) + "');"
            };

            result.ExecuteResult(context);
        }
        else
        {
            base.ExecuteResult(context);
        }
    }
}

AjaxRequestExtension

public static class AjaxRequestExtension
{
    public static bool IsAjaxRequest(this HttpRequest request)
    {
        return (request.Headers["X-Requested-With"] != null && request.Headers["X-Requested-With"] == "XMLHttpRequest");
    }
}

What are the true benefits of ExpandoObject?

There are some cases where this is handy. I'll use it for a Modularized shell for instance. Each module defines it's own Configuration Dialog databinded to it's settings. I provide it with an ExpandoObject as it's Datacontext and save the values in my configuration Storage. This way the Configuration Dialog writer just has to Bind to a Value and it's automatically created and saved. (And provided to the module for using these settings of course)

It' simply easier to use than an Dictionary. But everyone should be aware that internally it is just a Dictionary.

It's like LINQ just syntactic sugar, but it makes things easier sometimes.

So to answer your question directly: It's easier to write and easier to read. But technically it essentially is a Dictionary<string,object> (You can even cast it into one to list the values).

How to format a floating number to fixed width in Python

In python3 the following works:

>>> v=10.4
>>> print('% 6.2f' % v)
  10.40
>>> print('% 12.1f' % v)
        10.4
>>> print('%012.1f' % v)
0000000010.4

YYYY-MM-DD format date in shell script

Try to use this command :

date | cut -d " " -f2-4 | tr " " "-" 

The output would be like: 21-Feb-2021

Alternative to a goto statement in Java

There isn't any direct equivalent to the goto concept in Java. There are a few constructs that allow you to do some of the things you can do with a classic goto.

  • The break and continue statements allow you to jump out of a block in a loop or switch statement.
  • A labeled statement and break <label> allow you to jump out of an arbitrary compound statement to any level within a given method (or initializer block).
  • If you label a loop statement, you can continue <label> to continue with the next iteration of an outer loop from an inner loop.
  • Throwing and catching exceptions allows you to (effectively) jump out of many levels of a method call. (However, exceptions are relatively expensive and are considered to be a bad way to do "ordinary" control flow1.)
  • And of course, there is return.

None of these Java constructs allow you to branch backwards or to a point in the code at the same level of nesting as the current statement. They all jump out one or more nesting (scope) levels and they all (apart from continue) jump downwards. This restriction helps to avoid the goto "spaghetti code" syndrome inherent in old BASIC, FORTRAN and COBOL code2.


1- The most expensive part of exceptions is the actual creation of the exception object and its stacktrace. If you really, really need to use exception handling for "normal" flow control, you can either preallocate / reuse the exception object, or create a custom exception class that overrides the fillInStackTrace() method. The downside is that the exception's printStackTrace() methods won't give you useful information ... should you ever need to call them.

2 - The spaghetti code syndrome spawned the structured programming approach, where you limited in your use of the available language constructs. This could be applied to BASIC, Fortran and COBOL, but it required care and discipline. Getting rid of goto entirely was a pragmatically better solution. If you keep it in a language, there is always some clown who will abuse it.

How to keep console window open

There are two ways I know of

1) Console.ReadLine() at the end of the program. Disadvantage, you have to change your code and have to remember to take it out

2) Run outside of the debugger CONTROL-F5 this opens a console window outside of visual studio and that window won't close when finished. Advantage, you don't have to change your code. Disadvantage, if there is an exception, it won't drop into the debugger (however when you do get exceptions, you can simply just rerun it in the debugger)

Get the decimal part from a double

 string input = "0.55";
    var regex1 = new System.Text.RegularExpressions.Regex("(?<=[\\.])[0-9]+");
    if (regex1.IsMatch(input))
    {
        string dp= regex1.Match(input ).Value;
    }

How to format a date using ng-model?

Use custom validation of forms http://docs.angularjs.org/guide/forms Demo: http://plnkr.co/edit/NzeauIDVHlgeb6qF75hX?p=preview

Directive using formaters and parsers and MomentJS )

angModule.directive('moDateInput', function ($window) {
    return {
        require:'^ngModel',
        restrict:'A',
        link:function (scope, elm, attrs, ctrl) {
            var moment = $window.moment;
            var dateFormat = attrs.moDateInput;
            attrs.$observe('moDateInput', function (newValue) {
                if (dateFormat == newValue || !ctrl.$modelValue) return;
                dateFormat = newValue;
                ctrl.$modelValue = new Date(ctrl.$setViewValue);
            });

            ctrl.$formatters.unshift(function (modelValue) {
                if (!dateFormat || !modelValue) return "";
                var retVal = moment(modelValue).format(dateFormat);
                return retVal;
            });

            ctrl.$parsers.unshift(function (viewValue) {
                var date = moment(viewValue, dateFormat);
                return (date && date.isValid() && date.year() > 1950 ) ? date.toDate() : "";
            });
        }
    };
});

Display names of all constraints for a table in Oracle SQL

You need to query the data dictionary, specifically the USER_CONS_COLUMNS view to see the table columns and corresponding constraints:

SELECT *
  FROM user_cons_columns
 WHERE table_name = '<your table name>';

FYI, unless you specifically created your table with a lower case name (using double quotes) then the table name will be defaulted to upper case so ensure it is so in your query.

If you then wish to see more information about the constraint itself query the USER_CONSTRAINTS view:

SELECT *
  FROM user_constraints
 WHERE table_name = '<your table name>'
   AND constraint_name = '<your constraint name>';

If the table is held in a schema that is not your default schema then you might need to replace the views with:

all_cons_columns

and

all_constraints

adding to the where clause:

   AND owner = '<schema owner of the table>'

nodejs - first argument must be a string or Buffer - when using response.write with http.request

Well, obviously you are trying to send something which is not a string or buffer. :) It works with console, because console accepts anything. Simple example:

var obj = { test : "test" };
console.log( obj ); // works
res.write( obj ); // fails

One way to convert anything to string is to do that:

res.write( "" + obj );

whenever you are trying to send something. The other way is to call .toString() method:

res.write( obj.toString( ) );

Note that it still might not be what you are looking for. You should always pass strings/buffers to .write without such tricks.

As a side note: I assume that request is a asynchronous operation. If that's the case, then res.end(); will be called before any writing, i.e. any writing will fail anyway ( because the connection will be closed at that point ). Move that line into the handler:

request({
    uri: 'http://www.google.com',
    method: 'GET',
    maxRedirects:3
}, function(error, response, body) {
    if (!error) {
        res.write(response.statusCode);
    } else {
        //response.end(error);
        res.write(error);
    }
    res.end( );
});

How to capitalize the first letter in a String in Ruby

Use capitalize. From the String documentation:

Returns a copy of str with the first character converted to uppercase and the remainder to lowercase.

"hello".capitalize    #=> "Hello"
"HELLO".capitalize    #=> "Hello"
"123ABC".capitalize   #=> "123abc"

how to release localhost from Error: listen EADDRINUSE

use below command to kill a process running at a certain port - 3000 in this example below

kill -9 $(lsof -t -i:3000)

Could not obtain information about Windows NT group user

I was having the same issue, which turned out to be caused by the Domain login that runs the SQL service being locked out in AD. The lockout was caused by an unrelated usage of the service account for another purpose with the wrong password.

The errors received from SQL Agent logs did not mention the service account's name, just the name of the user (job owner) that couldn't be authenticated (since it uses the service account to check with AD).

Show popup after page load

Use this below code to display pop-up box on page load:

$(document).ready(function() { 
  var id = '#dialog';
  var maskHeight = $(document).height();
  var maskWidth = $(window).width();
  $('#mask').css({'width':maskWidth,'height':maskHeight}); 
  $('#mask').fadeIn(500); 
  $('#mask').fadeTo("slow",0.9); 
        var winH = $(window).height();
  var winW = $(window).width();
        $(id).css('top',  winH/2-$(id).height()/2);
  $(id).css('left', winW/2-$(id).width()/2);
     $(id).fadeIn(2000);  
     $('.window .close').click(function (e) {
  e.preventDefault();
  $('#mask').hide();
  $('.window').hide();
     });  
     $('#mask').click(function () {
  $(this).hide();
  $('.window').hide();
 });  

});

<div class="maintext">
<h2> Main text goes here...</h2>
</div>
<div id="boxes">
<div style="top: 50%; left: 50%; display: none;" id="dialog" class="window"> 
<div id="san">
<a href="#" class="close agree"><img src="close-icon.png" width="25" style="float:right; margin-right: -25px; margin-top: -20px;"></a>
<img src="san-web-corner.png" width="450">
</div>
</div>
<div style="width: 2478px; font-size: 32pt; color:white; height: 1202px; display: none; opacity: 0.4;" id="mask"></div>
</div>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.js"></script> 

I refereed this code from here Demo

Difference between Fact table and Dimension table?

Dimension table Dimension table is a table which contain attributes of measurements stored in fact tables. This table consists of hierarchies, categories and logic that can be used to traverse in nodes.

Fact table contains the measurement of business processes, and it contains foreign keys for the dimension tables.

Example – If the business process is manufacturing of bricks

Average number of bricks produced by one person/machine – measure of the business process

nginx- duplicate default server error

In my case junk files from editor caused the problem. I had a config as below:

#...
http {
 # ...
 include ../sites/*;
}

In the ../sites directory initially I had a default.config file. However, by mistake I saved duplicate files as default.config.save and default.config.save.1. Removing them resolved the issue.

Web.Config Debug/Release

To make the transform work in development (using F5 or CTRL + F5) I drop ctt.exe (https://ctt.codeplex.com/) in the packages folder (packages\ConfigTransform\ctt.exe).

Then I register a pre- or post-build event in Visual Studio...

$(SolutionDir)packages\ConfigTransform\ctt.exe source:"$(ProjectDir)connectionStrings.config" transform:"$(ProjectDir)connectionStrings.$(ConfigurationName).config" destination:"$(ProjectDir)connectionStrings.config"
$(SolutionDir)packages\ConfigTransform\ctt.exe source:"$(ProjectDir)web.config" transform:"$(ProjectDir)web.$(ConfigurationName).config" destination:"$(ProjectDir)web.config"

For the transforms I use SlowCheeta VS extension (https://visualstudiogallery.msdn.microsoft.com/69023d00-a4f9-4a34-a6cd-7e854ba318b5).

How do I get the current date in JavaScript?

If you're looking for a lot more granular control over the date formats, I thoroughly recommend checking out date-FNS. Terrific library - much smaller than moment.js and it's function based approach make it much faster then other class based libraries. Provide large number of operations needed over dates.

https://date-fns.org/docs/Getting-Started

How can I format a decimal to always show 2 decimal places?

In python 3, a way of doing this would be

'{:.2f}'.format(number)

DataSet panel (Report Data) in SSRS designer is gone

View -> Datasets (bottom of menu, above Refresh)

phpmysql error - #1273 - #1273 - Unknown collation: 'utf8mb4_general_ci'

When you export you use the compatibility system set to MYSQL40. Worked for me.

Sorting an ArrayList of objects using a custom sorting order

use this method:

private ArrayList<myClass> sortList(ArrayList<myClass> list) {
    if (list != null && list.size() > 1) {
        Collections.sort(list, new Comparator<myClass>() {
            public int compare(myClass o1, myClass o2) {
                if (o1.getsortnumber() == o2.getsortnumber()) return 0;
                return o1.getsortnumber() < o2.getsortnumber() ? 1 : -1;
            }
        });
    }
    return list;
}

`

and use: mySortedlist = sortList(myList); No need to implement comparator in your class. If you want inverse order swap 1 and -1

How to convert a string to utf-8 in Python

  • First, str in Python is represented in Unicode.
  • Second, UTF-8 is an encoding standard to encode Unicode string to bytes. There are many encoding standards out there (e.g. UTF-16, ASCII, SHIFT-JIS, etc.).

When the client sends data to your server and they are using UTF-8, they are sending a bunch of bytes not str.

You received a str because the "library" or "framework" that you are using, has implicitly converted some random bytes to str.

Under the hood, there is just a bunch of bytes. You just need ask the "library" to give you the request content in bytes and you will handle the decoding yourself (if library can't give you then it is trying to do black magic then you shouldn't use it).

  • Decode UTF-8 encoded bytes to str: bs.decode('utf-8')
  • Encode str to UTF-8 bytes: s.encode('utf-8')

CSS3 Transparency + Gradient

New syntax has been supported for a while by all modern browsers (starting from Chrome 26, Opera 12.1, IE 10 and Firefox 16): http://caniuse.com/#feat=css-gradients

background: linear-gradient(to bottom, rgba(0, 0, 0, 1), rgba(0, 0, 0, 0));

This renders a gradient, starting from solid black at the top, to fully transparent at the bottom.

Documentation on MDN.

How can I concatenate a string and a number in Python?

If it worked the way you expected it to (resulting in "abc9"), what would "9" + 9 deliver? 18 or "99"?

To remove this ambiguity, you are required to make explicit what you want to convert in this case:

"abc" + str(9)

Select Multiple Fields from List in Linq

You could use an anonymous type:

.Select(i => new { i.name, i.category_name })

The compiler will generate the code for a class with name and category_name properties and returns instances of that class. You can also manually specify property names:

i => new { Id = i.category_id, Name = i.category_name }

You can have arbitrary number of properties.

AngularJS: How do I manually set input to $valid in controller?

You cannot directly change a form's validity. If all the descendant inputs are valid, the form is valid, if not, then it is not.

What you should do is to set the validity of the input element. Like so;

addItem.capabilities.$setValidity("youAreFat", false);

Now the input (and so the form) is invalid. You can also see which error causes invalidation.

addItem.capabilities.errors.youAreFat == true;

In MVC, how do I return a string result?

You can just use the ContentResult to return a plain string:

public ActionResult Temp() {
    return Content("Hi there!");
}

ContentResult by default returns a text/plain as its contentType. This is overloadable so you can also do:

return Content("<xml>This is poorly formatted xml.</xml>", "text/xml");

What's the algorithm to calculate aspect ratio?

aspectRatio = width / height

if that is what you're after. You can then multiply it by one of the dimensions of the target space to find out the other (that maintains the ratio) e.g.

widthT = heightT * aspectRatio
heightT = widthT / aspectRatio

how to clear localstorage,sessionStorage and cookies in javascript? and then retrieve?

The standard Web Storage, does not say anything about the restoring any of these. So there won't be any standard way to do it. You have to go through the way the browsers implement these, or find a way to backup these before you delete them.

IllegalArgumentException or NullPointerException for a null parameter?

It seems like an IllegalArgumentException is called for if you don't want null to be an allowed value, and the NullPointerException would be thrown if you were trying to use a variable that turns out to be null.

How to get the current logged in user Id in ASP.NET Core

User.Identity.GetUserId();

does not exist in asp.net identity core 2.0. in this regard, i have managed in different way. i have created a common class for use whole application, because of getting user information.

create a common class PCommon & interface IPCommon adding reference using System.Security.Claims

using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;

namespace Common.Web.Helper
{
    public class PCommon: IPCommon
    {
        private readonly IHttpContextAccessor _context;
        public PayraCommon(IHttpContextAccessor context)
        {
            _context = context;
        }
        public int GetUserId()
        {
            return Convert.ToInt16(_context.HttpContext.User.FindFirstValue(ClaimTypes.NameIdentifier));
        }
        public string GetUserName()
        {
            return _context.HttpContext.User.Identity.Name;
        }

    }
    public interface IPCommon
    {
        int GetUserId();
        string GetUserName();        
    }    
}

Here the implementation of common class

using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.Extensions.Logging;
using Pay.DataManager.Concreate;
using Pay.DataManager.Helper;
using Pay.DataManager.Models;
using Pay.Web.Helper;
using Pay.Web.Models.GeneralViewModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Pay.Controllers
{

    [Authorize]
    public class BankController : Controller
    {

        private readonly IUnitOfWork _unitOfWork;
        private readonly ILogger _logger;
        private readonly IPCommon _iPCommon;


        public BankController(IUnitOfWork unitOfWork, IPCommon IPCommon, ILogger logger = null)
        {
            _unitOfWork = unitOfWork;
            _iPCommon = IPCommon;
            if (logger != null) { _logger = logger; }
        }


        public ActionResult Create()
        {
            BankViewModel _bank = new BankViewModel();
            CountryLoad(_bank);
            return View();
        }

        [HttpPost, ActionName("Create")]
        [ValidateAntiForgeryToken]
        public async Task<IActionResult> Insert(BankViewModel bankVM)
        {

            if (!ModelState.IsValid)
            {
                CountryLoad(bankVM);
                //TempData["show-message"] = Notification.Show(CommonMessage.RequiredFieldError("bank"), "Warning", type: ToastType.Warning);
                return View(bankVM);
            }


            try
            {
                bankVM.EntryBy = _iPCommon.GetUserId();
                var userName = _iPCommon.GetUserName()();
                //_unitOfWork.BankRepo.Add(ModelAdapter.ModelMap(new Bank(), bankVM));
                //_unitOfWork.Save();
               // TempData["show-message"] = Notification.Show(CommonMessage.SaveMessage(), "Success", type: ToastType.Success);
            }
            catch (Exception ex)
            {
               // TempData["show-message"] = Notification.Show(CommonMessage.SaveErrorMessage("bank"), "Error", type: ToastType.Error);
            }
            return RedirectToAction(nameof(Index));
        }



    }
}

get userId and name in insert action

_iPCommon.GetUserId();

Thanks, Maksud

Matplotlib: ValueError: x and y must have same first dimension

Changing your lists to numpy arrays will do the job!!

import matplotlib.pyplot as plt
from scipy import stats
import numpy as np 

x = np.array([0.46,0.59,0.68,0.99,0.39,0.31,1.09,0.77,0.72,0.49,0.55,0.62,0.58,0.88,0.78]) # x is a numpy array now
y = np.array([0.315,0.383,0.452,0.650,0.279,0.215,0.727,0.512,0.478,0.335,0.365,0.424,0.390,0.585,0.511]) # y is a numpy array now
xerr = [0.01]*15
yerr = [0.001]*15

plt.rc('font', family='serif', size=13)
m, b = np.polyfit(x, y, 1)
plt.plot(x,y,'s',color='#0066FF')
plt.plot(x, m*x + b, 'r-') #BREAKS ON THIS LINE
plt.errorbar(x,y,xerr=xerr,yerr=0,linestyle="None",color='black')
plt.xlabel('$\Delta t$ $(s)$',fontsize=20)
plt.ylabel('$\Delta p$ $(hPa)$',fontsize=20)
plt.autoscale(enable=True, axis=u'both', tight=False)
plt.grid(False)
plt.xlim(0.2,1.2)
plt.ylim(0,0.8)
plt.show()

enter image description here

dd: How to calculate optimal blocksize?

As others have said, there is no universally correct block size; what is optimal for one situation or one piece of hardware may be terribly inefficient for another. Also, depending on the health of the disks it may be preferable to use a different block size than what is "optimal".

One thing that is pretty reliable on modern hardware is that the default block size of 512 bytes tends to be almost an order of magnitude slower than a more optimal alternative. When in doubt, I've found that 64K is a pretty solid modern default. Though 64K usually isn't THE optimal block size, in my experience it tends to be a lot more efficient than the default. 64K also has a pretty solid history of being reliably performant: You can find a message from the Eug-Lug mailing list, circa 2002, recommending a block size of 64K here: http://www.mail-archive.com/[email protected]/msg12073.html

For determining THE optimal output block size, I've written the following script that tests writing a 128M test file with dd at a range of different block sizes, from the default of 512 bytes to a maximum of 64M. Be warned, this script uses dd internally, so use with caution.

dd_obs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_obs_testfile}
TEST_FILE_EXISTS=0
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=1; fi
TEST_FILE_SIZE=134217728

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Calculate number of segments required to copy
  COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))

  if [ $COUNT -le 0 ]; then
    echo "Block size of $BLOCK_SIZE estimated to require $COUNT blocks, aborting further tests."
    break
  fi

  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Create a test file with the specified block size
  DD_RESULT=$(dd if=/dev/zero of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync 2>&1 1>/dev/null)

  # Extract the transfer rate from dd's STDERR output
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  # Clean up the test file if we created one
  if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

  # Output the result
  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

View on GitHub

I've only tested this script on a Debian (Ubuntu) system and on OSX Yosemite, so it will probably take some tweaking to make work on other Unix flavors.

By default the command will create a test file named dd_obs_testfile in the current directory. Alternatively, you can provide a path to a custom test file by providing a path after the script name:

$ ./dd_obs_test.sh /path/to/disk/test_file

The output of the script is a list of the tested block sizes and their respective transfer rates like so:

$ ./dd_obs_test.sh
block size : transfer rate
       512 : 11.3 MB/s
      1024 : 22.1 MB/s
      2048 : 42.3 MB/s
      4096 : 75.2 MB/s
      8192 : 90.7 MB/s
     16384 : 101 MB/s
     32768 : 104 MB/s
     65536 : 108 MB/s
    131072 : 113 MB/s
    262144 : 112 MB/s
    524288 : 133 MB/s
   1048576 : 125 MB/s
   2097152 : 113 MB/s
   4194304 : 106 MB/s
   8388608 : 107 MB/s
  16777216 : 110 MB/s
  33554432 : 119 MB/s
  67108864 : 134 MB/s

(Note: The unit of the transfer rates will vary by OS)

To test optimal read block size, you could use more or less the same process, but instead of reading from /dev/zero and writing to the disk, you'd read from the disk and write to /dev/null. A script to do this might look like so:

dd_ibs_test.sh:

#!/bin/bash

# Since we're dealing with dd, abort if any errors occur
set -e

TEST_FILE=${1:-dd_ibs_testfile}
if [ -e "$TEST_FILE" ]; then TEST_FILE_EXISTS=$?; fi
TEST_FILE_SIZE=134217728

# Exit if file exists
if [ -e $TEST_FILE ]; then
  echo "Test file $TEST_FILE exists, aborting."
  exit 1
fi
TEST_FILE_EXISTS=1

if [ $EUID -ne 0 ]; then
  echo "NOTE: Kernel cache will not be cleared between tests without sudo. This will likely cause inaccurate results." 1>&2
fi

# Create test file
echo 'Generating test file...'
BLOCK_SIZE=65536
COUNT=$(($TEST_FILE_SIZE / $BLOCK_SIZE))
dd if=/dev/urandom of=$TEST_FILE bs=$BLOCK_SIZE count=$COUNT conv=fsync > /dev/null 2>&1

# Header
PRINTF_FORMAT="%8s : %s\n"
printf "$PRINTF_FORMAT" 'block size' 'transfer rate'

# Block sizes of 512b 1K 2K 4K 8K 16K 32K 64K 128K 256K 512K 1M 2M 4M 8M 16M 32M 64M
for BLOCK_SIZE in 512 1024 2048 4096 8192 16384 32768 65536 131072 262144 524288 1048576 2097152 4194304 8388608 16777216 33554432 67108864
do
  # Clear kernel cache to ensure more accurate test
  [ $EUID -eq 0 ] && [ -e /proc/sys/vm/drop_caches ] && echo 3 > /proc/sys/vm/drop_caches

  # Read test file out to /dev/null with specified block size
  DD_RESULT=$(dd if=$TEST_FILE of=/dev/null bs=$BLOCK_SIZE 2>&1 1>/dev/null)

  # Extract transfer rate
  TRANSFER_RATE=$(echo $DD_RESULT | \grep --only-matching -E '[0-9.]+ ([MGk]?B|bytes)/s(ec)?')

  printf "$PRINTF_FORMAT" "$BLOCK_SIZE" "$TRANSFER_RATE"
done

# Clean up the test file if we created one
if [ $TEST_FILE_EXISTS -ne 0 ]; then rm $TEST_FILE; fi

View on GitHub

An important difference in this case is that the test file is a file that is written by the script. Do not point this command at an existing file or the existing file will be overwritten with zeroes!

For my particular hardware I found that 128K was the most optimal input block size on a HDD and 32K was most optimal on a SSD.

Though this answer covers most of my findings, I've run into this situation enough times that I wrote a blog post about it: http://blog.tdg5.com/tuning-dd-block-size/ You can find more specifics on the tests I performed there.

How to increment datetime by custom months in python without using library

My very simple solution, which doesn't require any additional modules:

def addmonth(date):
    if date.day < 20:
        date2 = date+timedelta(32)
    else :
        date2 = date+timedelta(25)
    date2.replace(date2.year, date2.month, day)
    return date2

How to check if a file exists in a folder?

This is a way to see if any XML-files exists in that folder, yes.

To check for specific files use File.Exists(path), which will return a boolean indicating wheter the file at path exists.

Detect if a NumPy array contains at least one non-numeric value?

This should be faster than iterating and will work regardless of shape.

numpy.isnan(myarray).any()

Edit: 30x faster:

import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
    'numpy.isnan(a).any()',
    'any(numpy.isnan(x) for x in a.flatten())']
for m in ms:
    print "  %.2f s" % timeit.Timer(m, s).timeit(1000), m

Results:

  0.11 s numpy.isnan(a).any()
  3.75 s any(numpy.isnan(x) for x in a.flatten())

Bonus: it works fine for non-array NumPy types:

>>> a = numpy.float64(42.)
>>> numpy.isnan(a).any()
False
>>> a = numpy.float64(numpy.nan)
>>> numpy.isnan(a).any()
True

Why SQL Server throws Arithmetic overflow error converting int to data type numeric?

Numeric defines the TOTAL number of digits, and then the number after the decimal.

A numeric(3,2) can only hold up to 9.99.

Javascript change color of text and background to input value

Depending on which event you actually want to use (textbox change, or button click), you can try this:

HTML:

<input id="color" type="text" onchange="changeBackground(this);" />
<br />
<span id="coltext">This text should have the same color as you put in the text box</span>

JS:

function changeBackground(obj) {
    document.getElementById("coltext").style.color = obj.value;
}

DEMO: http://jsfiddle.net/6pLUh/

One minor problem with the button was that it was a submit button, in a form. When clicked, that submits the form (which ends up just reloading the page) and any changes from JavaScript are reset. Just using the onchange allows you to change the color based on the input.

Entity Framework Migrations renaming tables and columns

I just tried the same in EF6 (code first entity rename). I simply renamed the class and added a migration using the package manager console and voila, a migration using RenameTable(...) was automatically generated for me. I have to admit that I made sure the only change to the entity was renaming it so no new columns or renamed columns so I cannot be certain if this is an EF6 thing or just that EF was (always) able to detect such simple migrations.

How do you simulate Mouse Click in C#?

I have combined several sources to produce the code below, which I am currently using. I have also removed the Windows.Forms references so I can use it from console and WPF applications without additional references.

using System;
using System.Runtime.InteropServices;

public class MouseOperations
{
    [Flags]
    public enum MouseEventFlags
    {
        LeftDown = 0x00000002,
        LeftUp = 0x00000004,
        MiddleDown = 0x00000020,
        MiddleUp = 0x00000040,
        Move = 0x00000001,
        Absolute = 0x00008000,
        RightDown = 0x00000008,
        RightUp = 0x00000010
    }

    [DllImport("user32.dll", EntryPoint = "SetCursorPos")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool SetCursorPos(int x, int y);      

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool GetCursorPos(out MousePoint lpMousePoint);

    [DllImport("user32.dll")]
    private static extern void mouse_event(int dwFlags, int dx, int dy, int dwData, int dwExtraInfo);

    public static void SetCursorPosition(int x, int y) 
    {
        SetCursorPos(x, y);
    }

    public static void SetCursorPosition(MousePoint point)
    {
        SetCursorPos(point.X, point.Y);
    }

    public static MousePoint GetCursorPosition()
    {
        MousePoint currentMousePoint;
        var gotPoint = GetCursorPos(out currentMousePoint);
        if (!gotPoint) { currentMousePoint = new MousePoint(0, 0); }
        return currentMousePoint;
    }

    public static void MouseEvent(MouseEventFlags value)
    {
        MousePoint position = GetCursorPosition();

        mouse_event
            ((int)value,
             position.X,
             position.Y,
             0,
             0)
            ;
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct MousePoint
    {
        public int X;
        public int Y;

        public MousePoint(int x, int y)
        {
            X = x;
            Y = y;
        }
    }
}

Create table in SQLite only if it doesn't exist already

From http://www.sqlite.org/lang_createtable.html:

CREATE TABLE IF NOT EXISTS some_table (id INTEGER PRIMARY KEY AUTOINCREMENT, ...);

MySQL IF ELSEIF in select query

For your question :

SELECT id, 
   IF(qty_1 <= '23', price,
   IF(('23' > qty_1 && qty_2 <= '23'), price_2,
   IF(('23' > qty_2 && qty_3 <= '23'), price_3,
   IF(('23' > qty_2 && qty_3<='23'), price_3,
   IF('23' > qty_3, price_4, 1))))) as total 
FROM product;

You can use the if - else control structure or the IF function in MySQL.

Reference:
http://easysolutionweb.com/sql-pl-sql/how-to-use-if-and-else-in-mysql/

Pygame Drawing a Rectangle

here's how:

import pygame
screen=pygame.display.set_mode([640, 480])
screen.fill([255, 255, 255])
red=255
blue=0
green=0
left=50
top=50
width=90
height=90
filled=0
pygame.draw.rect(screen, [red, blue, green], [left, top, width, height], filled)
pygame.display.flip()
running=True
while running:
    for event in pygame.event.get():
        if event.type==pygame.QUIT:
            running=False
pygame.quit()

Invalid http_host header

settings.py

ALLOWED_HOSTS = ['*']

Python "SyntaxError: Non-ASCII character '\xe2' in file"

Plenty of good solutions here.

One challenge not really addressed in any of them is how to visually identify certain hard-to-spot non-ASCII characters that resemble other plain ASCII ones. For example, en dashes can appear almost exactly like hyphens and curly quotes look a lot like straight quotes, depending on your text editor's font.

This one-liner, which should work on Mac or Linux, will strip characters not in the ASCII printable range and show you the differences side-by-side:

# assumes Bash shell; for Bourne shell (sh), rearrange as a pipe and
# give '-' as second argument to 'sdiff' instead
sdiff --suppress-common-lines script.py <(tr -cd '\11\12\15\40-\176' <script.py)

The characters \11, \12, and \15 are tab, newline, and carriage return, respectively, in octal; the remaining range is the visible ASCII characters. (hat tip)

Another tip gleaned from this SO thread uses an inverse character class consisting of anything not in the ASCII visible range, and highlights it:

grep --color '[^ -~]' script.py

This should also work fine with the macOS / BSD version of grep.

Using a SELECT statement within a WHERE clause

Subquery is the name.

At times it's required, but good/bad depends on how it's applied.

C++, copy set to vector

here's another alternative using vector::assign:

theVector.assign(theSet.begin(), theSet.end());

PHP - get base64 img string decode and save as jpg (resulting empty image )

AFAIK, You have to use image function imagecreatefromstring, imagejpeg to create the images.

$imageData = base64_decode($imageData);
$source = imagecreatefromstring($imageData);
$rotate = imagerotate($source, $angle, 0); // if want to rotate the image
$imageSave = imagejpeg($rotate,$imageName,100);
imagedestroy($source);

Hope this will help.

PHP CODE WITH IMAGE DATA

$imageDataEncoded = base64_encode(file_get_contents('sample.png'));
$imageData = base64_decode($imageDataEncoded);
$source = imagecreatefromstring($imageData);
$angle = 90;
$rotate = imagerotate($source, $angle, 0); // if want to rotate the image
$imageName = "hello1.png";
$imageSave = imagejpeg($rotate,$imageName,100);
imagedestroy($source);

So Following is the php part of your program .. NOTE the change with comment Change is here

    $uploadedPhotos = array('photo_1','photo_2','photo_3','photo_4');
     foreach ($uploadedPhotos as $file) {
      if($this->input->post($file)){                   
         $imageData = base64_decode($this->input->post($file)); // <-- **Change is here for variable name only**
         $photo = imagecreatefromstring($imageData); // <-- **Change is here**

        /* Set name of the photo for show in the form */
        $this->session->set_userdata('upload_'.$file,'ant');
        /*set time of the upload*/
        if(!$this->session->userdata('uploading_on_datetime')){
         $this->session->set_userdata('uploading_on_datetime',time());
        }
         $datetime_upload = $this->session->userdata('uploading_on_datetime',true);

        /* create temp dir with time and user id */
        $new_dir = 'temp/user_'.$this->session->userdata('user_id',true).'_on_'.$datetime_upload.'/';
        if(!is_dir($new_dir)){
        @mkdir($new_dir);
        }
        /* move uploaded file with new name */
        // @file_put_contents( $new_dir.$file.'.jpg',imagejpeg($photo));
        imagejpeg($photo,$new_dir.$file.'.jpg',100); // <-- **Change is here**

      }
    }

Running SSH Agent when starting Git Bash on Windows

I could not get this to work based off the best answer, probably because I'm such a PC noob and missing something obvious. But just FYI in case it helps someone as challenged as me, what has FINALLY worked was through one of the links here (referenced in the answers). This involved simply pasting the following to my .bash_profile:

env=~/.ssh/agent.env

agent_load_env () { test -f "$env" && . "$env" >| /dev/null ; }

agent_start () {
    (umask 077; ssh-agent >| "$env")
    . "$env" >| /dev/null ; }

agent_load_env

# agent_run_state: 0=agent running w/ key; 1=agent w/o key; 2= agent not running
agent_run_state=$(ssh-add -l >| /dev/null 2>&1; echo $?)

if [ ! "$SSH_AUTH_SOCK" ] || [ $agent_run_state = 2 ]; then
    agent_start
    ssh-add
elif [ "$SSH_AUTH_SOCK" ] && [ $agent_run_state = 1 ]; then
    ssh-add
fi

unset env

I probably have something configured weird, but was not successful when I added it to my .profile or .bashrc. The other real challenge I've run into is I'm not an admin on this computer and can't change the environment variables without getting it approved by IT, so this is a solution for those that can't access that.

You know it's working if you're prompted for your ssh password when you open git bash. Hallelujah something finally worked.

Finding the length of an integer in C

int digits=1;

while (x>=10){
    x/=10;
    digits++;
}
return digits;

remove first element from array and return the array minus the first element

This can be done in one line with lodash _.tail:

_x000D_
_x000D_
var arr = ["item 1", "item 2", "item 3", "item 4"];_x000D_
console.log(_.tail(arr));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

Get the records of last month in SQL server

The way I fixed similar issue was by adding Month to my SELECT portion

Month DATEADD(day,Created_Date,'1971/12/31') As Month

and than I added WHERE statement

Month DATEADD(day,Created_Date,'1971/12/31') = month(getdate())-1

How does the SQL injection from the "Bobby Tables" XKCD comic work?

A single quote is the start and end of a string. A semicolon is the end of a statement. So if they were doing a select like this:

Select *
From Students
Where (Name = '<NameGetsInsertedHere>')

The SQL would become:

Select *
From Students
Where (Name = 'Robert'); DROP TABLE STUDENTS; --')
--             ^-------------------------------^

On some systems, the select would get ran first followed by the drop statement! The message is: DONT EMBED VALUES INTO YOUR SQL. Instead use parameters!

How to find out the number of CPUs using python

If you're interested into the number of processors available to your current process, you have to check cpuset first. Otherwise (or if cpuset is not in use), multiprocessing.cpu_count() is the way to go in Python 2.6 and newer. The following method falls back to a couple of alternative methods in older versions of Python:

import os
import re
import subprocess


def available_cpu_count():
    """ Number of available virtual or physical CPUs on this system, i.e.
    user/real as output by time(1) when called with an optimally scaling
    userspace-only program"""

    # cpuset
    # cpuset may restrict the number of *available* processors
    try:
        m = re.search(r'(?m)^Cpus_allowed:\s*(.*)$',
                      open('/proc/self/status').read())
        if m:
            res = bin(int(m.group(1).replace(',', ''), 16)).count('1')
            if res > 0:
                return res
    except IOError:
        pass

    # Python 2.6+
    try:
        import multiprocessing
        return multiprocessing.cpu_count()
    except (ImportError, NotImplementedError):
        pass

    # https://github.com/giampaolo/psutil
    try:
        import psutil
        return psutil.cpu_count()   # psutil.NUM_CPUS on old versions
    except (ImportError, AttributeError):
        pass

    # POSIX
    try:
        res = int(os.sysconf('SC_NPROCESSORS_ONLN'))

        if res > 0:
            return res
    except (AttributeError, ValueError):
        pass

    # Windows
    try:
        res = int(os.environ['NUMBER_OF_PROCESSORS'])

        if res > 0:
            return res
    except (KeyError, ValueError):
        pass

    # jython
    try:
        from java.lang import Runtime
        runtime = Runtime.getRuntime()
        res = runtime.availableProcessors()
        if res > 0:
            return res
    except ImportError:
        pass

    # BSD
    try:
        sysctl = subprocess.Popen(['sysctl', '-n', 'hw.ncpu'],
                                  stdout=subprocess.PIPE)
        scStdout = sysctl.communicate()[0]
        res = int(scStdout)

        if res > 0:
            return res
    except (OSError, ValueError):
        pass

    # Linux
    try:
        res = open('/proc/cpuinfo').read().count('processor\t:')

        if res > 0:
            return res
    except IOError:
        pass

    # Solaris
    try:
        pseudoDevices = os.listdir('/devices/pseudo/')
        res = 0
        for pd in pseudoDevices:
            if re.match(r'^cpuid@[0-9]+$', pd):
                res += 1

        if res > 0:
            return res
    except OSError:
        pass

    # Other UNIXes (heuristic)
    try:
        try:
            dmesg = open('/var/run/dmesg.boot').read()
        except IOError:
            dmesgProcess = subprocess.Popen(['dmesg'], stdout=subprocess.PIPE)
            dmesg = dmesgProcess.communicate()[0]

        res = 0
        while '\ncpu' + str(res) + ':' in dmesg:
            res += 1

        if res > 0:
            return res
    except OSError:
        pass

    raise Exception('Can not determine number of CPUs on this system')

Android: checkbox listener

Change RadioGroup group with CompoundButton buttonView and then press Ctrl+Shift+O to fix your imports.

background: fixed no repeat not working on mobile

Found a perfect solution for the problem 100% working on mobile as well as desktop

https://codepen.io/mrinaljain/pen/YObgEP

_x000D_
_x000D_
.jpx-is-wrapper {_x000D_
    display: block;_x000D_
    margin: 0 auto;_x000D_
    overflow: hidden;_x000D_
    position: relative;_x000D_
    z-index: 314749261;_x000D_
    width: 100vw;_x000D_
    height: 300px_x000D_
}_x000D_
_x000D_
.jpx-is-wrapper>.jpx-is-container {_x000D_
    background-color: transparent;_x000D_
    border: 0;_x000D_
    box-sizing: content-box;_x000D_
    clip: rect(auto auto auto auto);_x000D_
    color: black;_x000D_
    left: 0;_x000D_
    margin: 0 auto;_x000D_
    overflow: visible;_x000D_
    position: absolute;_x000D_
    text-align: left;_x000D_
    top: 0;_x000D_
    visibility: visible;_x000D_
    width: 100%;_x000D_
    z-index: auto;_x000D_
    height: 300px_x000D_
}_x000D_
_x000D_
.jpx-is-wrapper>.jpx-is-container>.jpx-is-content {_x000D_
    left: 0;_x000D_
    overflow: hidden;_x000D_
    right: 0;_x000D_
    top: 0;_x000D_
    visibility: visible;_x000D_
    width: 100%;_x000D_
    position: relative;_x000D_
    height: 300px;_x000D_
    display: block_x000D_
}_x000D_
_x000D_
.jpx-is-wrapper>.jpx-is-container>.jpx-is-content>.jpx-is-ad {_x000D_
    -webkit-box-shadow: rgba(0,0,0,0.65) 0 0 4px 2px;_x000D_
    -moz-box-shadow: rgba(0,0,0,0.65) 0 0 4px 2px;_x000D_
    box-shadow: rgba(0,0,0,0.65) 0 0 4px 2px;_x000D_
    bottom: 26px;_x000D_
    left: 0;_x000D_
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    text-align: center;_x000D_
    height: 588px;_x000D_
    top: 49px;_x000D_
    bottom: auto;_x000D_
    -webkit-transform: translateZ(0);_x000D_
    -moz-transform: translateZ(0);_x000D_
    -ms-transform: translateZ(0);_x000D_
    -o-transform: translateZ(0);_x000D_
    transform: translateZ(0)_x000D_
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    position: fixed_x000D_
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    width: 100%;_x000D_
    height: 100%_x000D_
}_x000D_
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.black-fader {_x000D_
    position: absolute;_x000D_
    z-index: 1;_x000D_
    width: 100%;_x000D_
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    opacity: 0.75_x000D_
}_x000D_
_x000D_
.video-containers {_x000D_
    position: absolute;_x000D_
    top: 0;_x000D_
    bottom: 0;_x000D_
    width: 100%;_x000D_
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    z-index: 0_x000D_
}_x000D_
_x000D_
.video-containers video,.video-containers img {_x000D_
    min-width: 100%;_x000D_
    min-height: 100%;_x000D_
    width: auto;_x000D_
    height: auto;_x000D_
    position: absolute;_x000D_
    top: 50%;_x000D_
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    transform: translate(-50%, -50%)_x000D_
}
_x000D_
<p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p>_x000D_
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<div class="jpx-is-wrapper">_x000D_
                       <div class="jpx-is-container">_x000D_
                          <div class="jpx-is-content">_x000D_
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                                  </div>_x000D_
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                    </div>_x000D_
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<p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p><p>Salman's arrest has created a wave of tension in Bollywood because of all his projects that were lined up, especially his most awaited film.</p>
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_x000D_
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Alter MySQL table to add comments on columns

try:

 ALTER TABLE `user` CHANGE `id` `id` INT( 11 ) COMMENT 'id of user'  

Generating a WSDL from an XSD file

Personally (and given what I know, i.e., Java and axis), I'd generate a Java data model from the .xsd files (Axis 2 can do this), and then add an interface to describe my web service that uses that model, and then generate a WSDL from that interface.

Because .NET has all these features as well, it must be possible to do all this in that ecosystem as well.

C# equivalent of C++ map<string,double>

Although System.Collections.Generic.Dictionary matches the tag "hashmap" and will work well in your example, it is not an exact equivalent of C++'s std::map - std::map is an ordered collection.

If ordering is important you should use SortedDictionary.

Overlay a background-image with an rgba background-color

_x000D_
_x000D_
/* Working method */_x000D_
.tinted-image {_x000D_
  background: _x000D_
    /* top, transparent red, faked with gradient */ _x000D_
    linear-gradient(_x000D_
      rgba(255, 0, 0, 0.45), _x000D_
      rgba(255, 0, 0, 0.45)_x000D_
    ),_x000D_
    /* bottom, image */_x000D_
    url(https://upload.wikimedia.org/wikipedia/commons/7/73/Lion_waiting_in_Namibia.jpg);_x000D_
    height: 1280px;_x000D_
    width: 960px;_x000D_
    background-size: cover;_x000D_
}_x000D_
_x000D_
.tinted-image p {_x000D_
    color: #fff;_x000D_
    padding: 100px;_x000D_
  }
_x000D_
<div class="tinted-image">_x000D_
  _x000D_
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Laboriosam distinctio, temporibus tempora a eveniet quas  qui veritatis sunt perferendis harum!</p>_x000D_
  _x000D_
</div>
_x000D_
_x000D_
_x000D_

source: https://css-tricks.com/tinted-images-multiple-backgrounds/

Print out the values of a (Mat) matrix in OpenCV C++

If you are using opencv3, you can print Mat like python numpy style:

Mat xTrainData = (Mat_<float>(5,2) << 1, 1, 1, 1, 2, 2, 2, 2, 2, 2);

cout << "xTrainData (python)  = " << endl << format(xTrainData, Formatter::FMT_PYTHON) << endl << endl;

Output as below, you can see it'e more readable, see here for more information.

enter image description here

But in most case, there is no need to output all the data in Mat, you can output by row range like 0 ~ 2 row:

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

#include <iostream>
#include <iomanip>

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    //row: 6, column: 3,unsigned one channel
    Mat image1(6, 3, CV_8UC1, 5);

    // output row: 0 ~ 2
    cout << "image1 row: 0~2 = "<< endl << " "  << image1.rowRange(0, 2) << endl << endl;

    //row: 8, column: 2,unsigned three channel
    Mat image2(8, 2, CV_8UC3, Scalar(1, 2, 3));

    // output row: 0 ~ 2
    cout << "image2 row: 0~2 = "<< endl << " "  << image2.rowRange(0, 2) << endl << endl;

    return 0;
}

Output as below:

enter image description here

Simple int to char[] conversion

Use this. Beware of i's larger than 9, as these will require a char array with more than 2 elements to avoid a buffer overrun.

char c[2];
int i=1;
sprintf(c, "%d", i);

Validation error: "No validator could be found for type: java.lang.Integer"

For this type error: UnexpectedTypeException ERROR: We are trying to use incorrect Hibernate validator annotation on any bean property. For this same issue for my Springboot project( validating type 'java.lang.Integer')

The solution that worked for me is using @NotNull for Integer.

How to Clear Console in Java?

If you are using windows and are interested in clearing the screen before running the program, you can compile the file call it from a .bat file. for example:


cls

java "what ever the name of the compiles class is"


Save as "etc".bat and then running by calling it in the command prompt or double clicking the file

Why doesn't importing java.util.* include Arrays and Lists?

The difference between

import java.util.*;

and

import java.util.*;
import java.util.List;
import java.util.Arrays;

becomes apparent when the code refers to some other List or Arrays (for example, in the same package, or also imported generally). In the first case, the compiler will assume that the Arrays declared in the same package is the one to use, in the latter, since it is declared specifically, the more specific java.util.Arrays will be used.

How to check if div element is empty

if ($("#cartContent").children().length == 0) 
{
     // no child
}

How to call a php script/function on a html button click

Modify the_script.php like this.

<script>
the_function() {
    alert("You win");
}
</script>

Merging multiple PDFs using iTextSharp in c#.net

Using iTextSharp.dll

protected void Page_Load(object sender, EventArgs e)
{
    String[] files = @"C:\ENROLLDOCS\A1.pdf,C:\ENROLLDOCS\A2.pdf".Split(',');
    MergeFiles(@"C:\ENROLLDOCS\New1.pdf", files);
}
public void MergeFiles(string destinationFile, string[] sourceFiles)
{
    if (System.IO.File.Exists(destinationFile))
        System.IO.File.Delete(destinationFile);

    string[] sSrcFile;
    sSrcFile = new string[2];

    string[] arr = new string[2];
    for (int i = 0; i <= sourceFiles.Length - 1; i++)
    {
        if (sourceFiles[i] != null)
        {
            if (sourceFiles[i].Trim() != "")
                arr[i] = sourceFiles[i].ToString();
        }
    }

    if (arr != null)
    {
        sSrcFile = new string[2];

        for (int ic = 0; ic <= arr.Length - 1; ic++)
        {
            sSrcFile[ic] = arr[ic].ToString();
        }
    }
    try
    {
        int f = 0;

        PdfReader reader = new PdfReader(sSrcFile[f]);
        int n = reader.NumberOfPages;
        Response.Write("There are " + n + " pages in the original file.");
        Document document = new Document(PageSize.A4);

        PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(destinationFile, FileMode.Create));

        document.Open();
        PdfContentByte cb = writer.DirectContent;
        PdfImportedPage page;

        int rotation;
        while (f < sSrcFile.Length)
        {
            int i = 0;
            while (i < n)
            {
                i++;

                document.SetPageSize(PageSize.A4);
                document.NewPage();
                page = writer.GetImportedPage(reader, i);

                rotation = reader.GetPageRotation(i);
                if (rotation == 90 || rotation == 270)
                {
                    cb.AddTemplate(page, 0, -1f, 1f, 0, 0, reader.GetPageSizeWithRotation(i).Height);
                }
                else
                {
                    cb.AddTemplate(page, 1f, 0, 0, 1f, 0, 0);
                }
                Response.Write("\n Processed page " + i);
            }

            f++;
            if (f < sSrcFile.Length)
            {
                reader = new PdfReader(sSrcFile[f]);
                n = reader.NumberOfPages;
                Response.Write("There are " + n + " pages in the original file.");
            }
        }
        Response.Write("Success");
        document.Close();
    }
    catch (Exception e)
    {
        Response.Write(e.Message);
    }


}

IE6/IE7 css border on select element

It solves to me, for my purposes:

.select-container {
  position:relative;
  width:200px;
  height:18px;
  overflow:hidden;
  border:1px solid white !important
}
.select-container select {
  position:relative;
  left:-2px;
  top:-2px
}

To put more style will be necessary to use nested divs .

What causes HttpHostConnectException?

In my case the issue was a missing 's' in the HTTP URL. Error was: "HttpHostConnectException: Connect to someendpoint.com:80 [someendpoint.com/127.0.0.1] failed: Connection refused" End point and IP obviously changed to protect the network.

Migration: Cannot add foreign key constraint

You should write in this way

public function up()
{
    Schema::create('transactions', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->float('amount', 11, 2);
        $table->enum('transaction type', ['debit', 'credit']);
        $table->bigInteger('customer_id')->unsigned();      
        $table->timestamps();                 
    });

    Schema::table('transactions', function($table) {
        $table->foreign('customer_id')
              ->references('id')->on('customers')
              ->onDelete('cascade');
    });     
}

The foreign key field should be unsigned, hope it helps!!

Convert a 1D array to a 2D array in numpy

You can useflatten() from the numpy package.

import numpy as np
a = np.array([[1, 2],
       [3, 4],
       [5, 6]])
a_flat = a.flatten()
print(f"original array: {a} \nflattened array = {a_flat}")

Output:

original array: [[1 2]
 [3 4]
 [5 6]] 
flattened array = [1 2 3 4 5 6]

File path to resource in our war/WEB-INF folder?

There's a couple ways of doing this. As long as the WAR file is expanded (a set of files instead of one .war file), you can use this API:

ServletContext context = getContext();
String fullPath = context.getRealPath("/WEB-INF/test/foo.txt");

http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/ServletContext.html#getRealPath(java.lang.String)

That will get you the full system path to the resource you are looking for. However, that won't work if the Servlet Container never expands the WAR file (like Tomcat). What will work is using the ServletContext's getResource methods.

ServletContext context = getContext();
URL resourceUrl = context.getResource("/WEB-INF/test/foo.txt");

or alternatively if you just want the input stream:

InputStream resourceContent = context.getResourceAsStream("/WEB-INF/test/foo.txt");

http://tomcat.apache.org/tomcat-5.5-doc/servletapi/javax/servlet/ServletContext.html#getResource(java.lang.String)

The latter approach will work no matter what Servlet Container you use and where the application is installed. The former approach will only work if the WAR file is unzipped before deployment.

EDIT: The getContext() method is obviously something you would have to implement. JSP pages make it available as the context field. In a servlet you get it from your ServletConfig which is passed into the servlet's init() method. If you store it at that time, you can get your ServletContext any time you want after that.

Difference between Build Solution, Rebuild Solution, and Clean Solution in Visual Studio?

The one major thing I think people are leaving out is that Build and Clean are both tasks that are performed based on Visual Studio's knowledge of your Project/Solution. I see a lot of complaining that Clean doesn't work or leaves leftover files or is not trustworthy, when in fact, the reasons you say it isn't trustworthy actually makes it more trustworthy.

Clean will only remove (clean) files and/or directories that Visual Studio or the compiler themselves have in fact created. If you copy your own files or files/folder structures get created from an outside tool or source, then Visual Studio doesn't "know they exist" and therefore, should not touch them.

Can you imagine if the Clean operation basically performed a "del *.*" ? This could be catastrophic.

Build performs a compile on changed or necessary projects.

Rebuild performs a compile regardless of change or what's necessary.

Clean removes files/folders it has created in the past, but leaves anything that it didn't have anything to do with, initially.

I hope this elaborates a bit and helps.

How to read a text file into a string variable and strip newlines?

Maybe you could try this? I use this in my programs.

Data= open ('data.txt', 'r')
data = Data.readlines()
for i in range(len(data)):
    data[i] = data[i].strip()+ ' '
data = ''.join(data).strip()

Entity Framework and SQL Server View

Agree with @Tillito, however in most cases it will foul SQL optimizer and it will not use right indexes.

It may be obvious for somebody, but I burned hours solving performance issues using Tillito solution. Lets say you have the table:

 Create table OrderDetail
    (  
       Id int primary key,
       CustomerId int references Customer(Id),
       Amount decimal default(0)
    );
 Create index ix_customer on OrderDetail(CustomerId);

and your view is something like this

 Create view CustomerView
    As
      Select 
          IsNull(CustomerId, -1) as CustomerId, -- forcing EF to use it as key
          Sum(Amount) as Amount
      From OrderDetail
      Group by CustomerId

Sql optimizer will not use index ix_customer and it will perform table scan on primary index, but if instead of:

Group by CustomerId

you use

Group by IsNull(CustomerId, -1)

it will make MS SQL (at least 2008) include right index into plan.

If

What are the differences and similarities between ffmpeg, libav, and avconv?

Confusing messages

These messages are rather misleading and understandably a source of confusion. Older Ubuntu versions used Libav which is a fork of the FFmpeg project. FFmpeg returned in Ubuntu 15.04 "Vivid Vervet".

The fork was basically a non-amicable result of conflicting personalities and development styles within the FFmpeg community. It is worth noting that the maintainer for Debian/Ubuntu switched from FFmpeg to Libav on his own accord due to being involved with the Libav fork.

The real ffmpeg vs the fake one

For a while both Libav and FFmpeg separately developed their own version of ffmpeg.

Libav then renamed their bizarro ffmpeg to avconv to distance themselves from the FFmpeg project. During the transition period the "not developed anymore" message was displayed to tell users to start using avconv instead of their counterfeit version of ffmpeg. This confused users into thinking that FFmpeg (the project) is dead, which is not true. A bad choice of words, but I can't imagine Libav not expecting such a response by general users.

This message was removed upstream when the fake "ffmpeg" was finally removed from the Libav source, but, depending on your version, it can still show up in Ubuntu because the Libav source Ubuntu uses is from the ffmpeg-to-avconv transition period.

In June 2012, the message was re-worded for the package libav - 4:0.8.3-0ubuntu0.12.04.1. Unfortunately the new "deprecated" message has caused additional user confusion.

Starting with Ubuntu 15.04 "Vivid Vervet", FFmpeg's ffmpeg is back in the repositories again.

libav vs Libav

To further complicate matters, Libav chose a name that was historically used by FFmpeg to refer to its libraries (libavcodec, libavformat, etc). For example the libav-user mailing list, for questions and discussions about using the FFmpeg libraries, is unrelated to the Libav project.

How to tell the difference

If you are using avconv then you are using Libav. If you are using ffmpeg you could be using FFmpeg or Libav. Refer to the first line in the console output to tell the difference: the copyright notice will either mention FFmpeg or Libav.

Secondly, the version numbering schemes differ. Each of the FFmpeg or Libav libraries contains a version.h header which shows a version number. FFmpeg will end in three digits, such as 57.67.100, and Libav will end in one digit such as 57.67.0. You can also view the library version numbers by running ffmpeg or avconv and viewing the console output.

If you want to use the real ffmpeg

Ubuntu 15.04 "Vivid Vervet" or newer

The real ffmpeg is in the repository, so you can install it with:

apt-get install ffmpeg

For older Ubuntu versions

Your options are:

These methods are non-intrusive, reversible, and will not interfere with the system or any repository packages.

Another possible option is to upgrade to Ubuntu 15.04 "Vivid Vervet" or newer and just use ffmpeg from the repository.

Also see

For an interesting blog article on the situation, as well as a discussion about the main technical differences between the projects, see The FFmpeg/Libav situation.

Inheriting from a template class in c++

#include<iostream>

using namespace std;

template<class t> 
class base {
protected:
    t a;
public:
    base(t aa){
        a = aa;
        cout<<"base "<<a<<endl;
    }
};

template <class t> 
class derived: public base<t>{
    public:
        derived(t a): base<t>(a) {
        }
        //Here is the method in derived class 
    void sampleMethod() {
        cout<<"In sample Method"<<endl;
    }
};

int main() {
    derived<int> q(1);
    // calling the methods
    q.sampleMethod();
}

Print ArrayList

Add toString() method to your address class then do

System.out.println(Arrays.toString(houseAddress));

Why ModelState.IsValid always return false in mvc

Please post your Model Class.

To check the errors in your ModelState use the following code:

var errors = ModelState
    .Where(x => x.Value.Errors.Count > 0)
    .Select(x => new { x.Key, x.Value.Errors })
    .ToArray();

OR: You can also use

var errors = ModelState.Values.SelectMany(v => v.Errors);

Place a break point at the above line and see what are the errors in your ModelState.

jQuery DataTables Getting selected row values

var table = $('#myTableId').DataTable();
var a= [];
$.each(table.rows('.myClassName').data(), function() {
a.push(this["productId"]);
});

console.log(a[0]);

How to view/delete local storage in Firefox?

From Firefox 34 onwards you now have an option for Storage Inspector, which you can enable it from developer tools settings

Once there, you can enable the Storage options under Default Firefox Developer tools

Updated 27-3-16

Firefox 48.0a1 now supports Cookies editing.

Updated 3-4-16

Firefox 48.0a1 now supports localStorage and sessionStorage editing.

Updated 02-08-16

Firefox 48 (stable release) and onward supports editing of all storage types, except IndexedDB

lambda expression for exists within list

If listOfIds is a list, this will work, but, List.Contains() is a linear search, so this isn't terribly efficient.

You're better off storing the ids you want to look up into a container that is suited for searching, like Set.

List<int> listOfIds = new List(GetListOfIds());
lists.Where(r=>listOfIds.Contains(r.Id));

What does string::npos mean in this code?

static const size_t npos = -1;

Maximum value for size_t

npos is a static member constant value with the greatest possible value for an element of type size_t.

This value, when used as the value for a len (or sublen) parameter in string's member functions, means "until the end of the string".

As a return value, it is usually used to indicate no matches.

This constant is defined with a value of -1, which because size_t is an unsigned integral type, it is the largest possible representable value for this type.

The "backspace" escape character '\b': unexpected behavior?

Use a single backspace after each character printf("hello wor\bl\bd\n");

How to generate the whole database script in MySQL Workbench?

Try the export function of phpMyAdmin.

I think there is also a possibility to copy the database files from one server to another, but I do not have a server available at the moment so I can't test it.

Serialize JavaScript object into JSON string

Below is another way by which we can JSON data with JSON.stringify() function

var Utils = {};
Utils.MyClass1 = function (id, member) {
    this.id = id;
    this.member = member;
}
var myobject = { MyClass1: new Utils.MyClass1("5678999", "text") };
alert(JSON.stringify(myobject));

Increase distance between text and title on the y-axis

Based on this forum post: https://groups.google.com/forum/#!topic/ggplot2/mK9DR3dKIBU

Sounds like the easiest thing to do is to add a line break (\n) before your x axis, and after your y axis labels. Seems a lot easier (although dumber) than the solutions posted above.

ggplot(mpg, aes(cty, hwy)) + 
    geom_point() + 
    xlab("\nYour_x_Label") + ylab("Your_y_Label\n")

Hope that helps!

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

Remove IE10's "clear field" X button on certain inputs?

I would apply this rule to all input fields of type text, so it doesn't need to be duplicated later:

input[type=text]::-ms-clear { display: none; }

One can even get less specific by using just:

::-ms-clear { display: none; }

I have used the later even before adding this answer, but thought that most people would prefer to be more specific than that. Both solutions work fine.

Select last N rows from MySQL

SELECT * FROM table ORDER BY id DESC LIMIT 50

save resources make one query, there is no need to make nested queries

How to check if an Object is a Collection Type in Java?

Java conveniently has the instanceof operator (JLS 15.20.2) to test if a given object is of a given type.

 if (x instanceof List<?>) {   
    List<?> list = (List<?>) x;
    // do something with list
 } else if (x instanceof Collection<?>) {
    Collection<?> col = (Collection<?>) x;
    // do something with col
 }

One thing should be mentioned here: it's important in these kinds of constructs to check in the right order. You will find that if you had swapped the order of the check in the above snippet, the code will still compile, but it will no longer work. That is the following code doesn't work:

 // DOESN'T WORK! Wrong order!
 if (x instanceof Collection<?>) {
    Collection<?> col = (Collection<?>) x;
    // do something with col
 } else if (x instanceof List<?>) { // this will never be reached!
    List<?> list = (List<?>) x;
    // do something with list
 }

The problem is that a List<?> is-a Collection<?>, so it will pass the first test, and the else means that it will never reach the second test. You have to test from the most specific to the most general type.

write newline into a file

just use \r\n for endline if you are using windows operating system.

How to check which locks are held on a table

I use a Dynamic Management View (DMV) to capture locks as well as the object_id or partition_id of the item that is locked.

(MUST switch to the Database you want to observe to get object_id)

SELECT 
     TL.resource_type,
     TL.resource_database_id,
     TL.resource_associated_entity_id,
     TL.request_mode,
     TL.request_session_id,
     WT.blocking_session_id,
     O.name AS [object name],
     O.type_desc AS [object descr],
     P.partition_id AS [partition id],
     P.rows AS [partition/page rows],
     AU.type_desc AS [index descr],
     AU.container_id AS [index/page container_id]
FROM sys.dm_tran_locks AS TL
INNER JOIN sys.dm_os_waiting_tasks AS WT 
 ON TL.lock_owner_address = WT.resource_address
LEFT OUTER JOIN sys.objects AS O 
 ON O.object_id = TL.resource_associated_entity_id
LEFT OUTER JOIN sys.partitions AS P 
 ON P.hobt_id = TL.resource_associated_entity_id
LEFT OUTER JOIN sys.allocation_units AS AU 
 ON AU.allocation_unit_id = TL.resource_associated_entity_id;

How to find Max Date in List<Object>?

Just use Kotlin!

val list = listOf(user1, user2, user3)
val maxDate = list.maxBy { it.date }?.date

How do I embed PHP code in JavaScript?

PHP has to be parsed on the server. JavaScript is working in the client's browser.

Having PHP code in a .js file will not work, except you can tell the server to parse the file you want to have as .js before it sends it to the client. And telling the server is the easiest thing in the world: just add .php at the end of the filename.

So, you could name it javascript.php. Or, so you know what this file is PRIMARILY, you could name it javascript.js.php - the server will recognize it as .php and parse it.

Where are static methods and static variables stored in Java?

Prior to Java 8:

The static variables were stored in the permgen space(also called the method area).

PermGen Space is also known as Method Area

PermGen Space used to store 3 things

  1. Class level data (meta-data)
  2. interned strings
  3. static variables

From Java 8 onwards

The static variables are stored in the Heap itself.From Java 8 onwards the PermGen Space have been removed and new space named as MetaSpace is introduced which is not the part of Heap any more unlike the previous Permgen Space. Meta-Space is present on the native memory (memory provided by the OS to a particular Application for its own usage) and it now only stores the class meta-data.

The interned strings and static variables are moved into the heap itself.

For official information refer : JEP 122:Remove the Permanent Gen Space

Comparing two dataframes and getting the differences

Building on alko's answer that almost worked for me, except for the filtering step (where I get: ValueError: cannot reindex from a duplicate axis), here is the final solution I used:

# join the dataframes
united_data = pd.concat([data1, data2, data3, ...])
# group the data by the whole row to find duplicates
united_data_grouped = united_data.groupby(list(united_data.columns))
# detect the row indices of unique rows
uniq_data_idx = [x[0] for x in united_data_grouped.indices.values() if len(x) == 1]
# extract those unique values
uniq_data = united_data.iloc[uniq_data_idx]

Spring MVC 4: "application/json" Content Type is not being set correctly

Not exactly for this OP, but for those who encountered 404 and cannot set response content-type to "application/json" (any content-type). One possibility is a server actually responds 406 but explorer (e.g., chrome) prints it as 404.

If you do not customize message converter, spring would use AbstractMessageConverterMethodProcessor.java. It would run:

List<MediaType> requestedMediaTypes = getAcceptableMediaTypes(request);
List<MediaType> producibleMediaTypes = getProducibleMediaTypes(request, valueType, declaredType);

and if they do not have any overlapping (the same item), it would throw HttpMediaTypeNotAcceptableException and this finally causes 406. No matter if it is an ajax, or GET/POST, or form action, if the request uri ends with a .html or any suffix, the requestedMediaTypes would be "text/[that suffix]", and this conflicts with producibleMediaTypes, which is usually:

"application/json"  
"application/xml"   
"text/xml"          
"application/*+xml" 
"application/json"  
"application/*+json"
"application/json"  
"application/*+json"
"application/xml"   
"text/xml"          
"application/*+xml"
"application/xml"  
"text/xml"         
"application/*+xml"

React Router with optional path parameter

The edit you posted was valid for an older version of React-router (v0.13) and doesn't work anymore.


React Router v1, v2 and v3

Since version 1.0.0 you define optional parameters with:

<Route path="to/page(/:pathParam)" component={MyPage} />

and for multiple optional parameters:

<Route path="to/page(/:pathParam1)(/:pathParam2)" component={MyPage} />

You use parenthesis ( ) to wrap the optional parts of route, including the leading slash (/). Check out the Route Matching Guide page of the official documentation.

Note: The :paramName parameter matches a URL segment up to the next /, ?, or #. For more about paths and params specifically, read more here.


React Router v4 and above

React Router v4 is fundamentally different than v1-v3, and optional path parameters aren't explicitly defined in the official documentation either.

Instead, you are instructed to define a path parameter that path-to-regexp understands. This allows for much greater flexibility in defining your paths, such as repeating patterns, wildcards, etc. So to define a parameter as optional you add a trailing question-mark (?).

As such, to define an optional parameter, you do:

<Route path="/to/page/:pathParam?" component={MyPage} />

and for multiple optional parameters:

<Route path="/to/page/:pathParam1?/:pathParam2?" component={MyPage} />

Note: React Router v4 is incompatible with (read more here). Use version v3 or earlier (v2 recommended) instead.

Javascript to Select Multiple options

This type of thing should be done server-side, so as to limit the amount of resources used on the client for such trivial tasks. That being said, if you were to do it on the front-end, I would encourage you to consider using something like underscore.js to keep the code clean and concise:

var values = ["Red", "Green"],
    colors = document.getElementById("colors");

_.each(colors.options, function (option) {
    option.selected = ~_.indexOf(values, option.text);
});

If you're using jQuery, it could be even more terse:

var values = ["Red", "Green"];

$("#colors option").prop("selected", function () {
    return ~$.inArray(this.text, values);
});

If you were to do this without a tool like underscore.js or jQuery, you would have a bit more to write, and may find it to be a bit more complicated:

var color, i, j,
    values = ["Red", "Green"],
    options = document.getElementById("colors").options;

for ( i = 0; i < values.length; i++ ) {
    for ( j = 0, color = values[i]; j < options.length; j++ ) {
        options[j].selected = options[j].selected || color === options[j].text;
    }
}

Webpack "OTS parsing error" loading fonts

In my case adding following lines to lambda.js {my deployed is on AWS Lambda} fixed the issue.

 'font/opentype',
 'font/sfnt',
 'font/ttf',
 'font/woff',
 'font/woff2'

Color theme for VS Code integrated terminal

The best colors I've found --which aside from being so beautiful, are very easy to look at too and do not boil my eyes-- are the ones I've found listed in this GitHub repository: VSCode Snazzy

Very Easy Installation:

Copy the contents of snazzy.json into your VS Code "settings.json" file.

(In case you don't know how to open the "settings.json" file, first hit Ctrl+Shift+P and then write Preferences: open settings(JSON) and hit enter).


Notice: For those who have tried ColorTool and it works outside VSCode but not inside VSCode, you've made no mistakes in implementing it, that's just a decision of VSCode developers for the VSCode's terminal to be colored independently.

linq where list contains any in list

Sounds like you want:

var movies = _db.Movies.Where(p => p.Genres.Intersect(listOfGenres).Any());

How to split a string to 2 strings in C

char *line = strdup("user name"); // don't do char *line = "user name"; see Note

char *first_part = strtok(line, " "); //first_part points to "user"
char *sec_part = strtok(NULL, " ");   //sec_part points to "name"

Note: strtok modifies the string, so don't hand it a pointer to string literal.