Programs & Examples On #Stm32

The STM32 is a line of microcontrollers from ST Microelectronics, based on the Cortex M0, M0+, M3, M4, or M7 ARM core (depending on the product family).

Make Error 127 when running trying to compile code

Error 127 means one of two things:

  1. file not found: the path you're using is incorrect. double check that the program is actually in your $PATH, or in this case, the relative path is correct -- remember that the current working directory for a random terminal might not be the same for the IDE you're using. it might be better to just use an absolute path instead.
  2. ldso is not found: you're using a pre-compiled binary and it wants an interpreter that isn't on your system. maybe you're using an x86_64 (64-bit) distro, but the prebuilt is for x86 (32-bit). you can determine whether this is the answer by opening a terminal and attempting to execute it directly. or by running file -L on /bin/sh (to get your default/native format) and on the compiler itself (to see what format it is).

if the problem is (2), then you can solve it in a few diff ways:

  1. get a better binary. talk to the vendor that gave you the toolchain and ask them for one that doesn't suck.
  2. see if your distro can install the multilib set of files. most x86_64 64-bit distros allow you to install x86 32-bit libraries in parallel.
  3. build your own cross-compiler using something like crosstool-ng.
  4. you could switch between an x86_64 & x86 install, but that seems a bit drastic ;).

How can I solve Exception in thread "main" java.lang.NullPointerException error

This is the problem

double a[] = null;

Since a is null, NullPointerException will arise every time you use it until you initialize it. So this:

a[i] = var;

will fail.

A possible solution would be initialize it when declaring it:

double a[] = new double[PUT_A_LENGTH_HERE]; //seems like this constant should be 7

IMO more important than solving this exception, is the fact that you should learn to read the stacktrace and understand what it says, so you could detect the problems and solve it.

java.lang.NullPointerException

This exception means there's a variable with null value being used. How to solve? Just make sure the variable is not null before being used.

at twoten.TwoTenB.(TwoTenB.java:29)

This line has two parts:

  • First, shows the class and method where the error was thrown. In this case, it was at <init> method in class TwoTenB declared in package twoten. When you encounter an error message with SomeClassName.<init>, means the error was thrown while creating a new instance of the class e.g. executing the constructor (in this case that seems to be the problem).
  • Secondly, shows the file and line number location where the error is thrown, which is between parenthesis. This way is easier to spot where the error arose. So you have to look into file TwoTenB.java, line number 29. This seems to be a[i] = var;.

From this line, other lines will be similar to tell you where the error arose. So when reading this:

at javapractice.JavaPractice.main(JavaPractice.java:32)

It means that you were trying to instantiate a TwoTenB object reference inside the main method of your class JavaPractice declared in javapractice package.

Adding JPanel to JFrame

public class Test{

Test2 test = new Test2();
JFrame frame = new JFrame();

Test(){
...
frame.setLayout(new BorderLayout());
frame.add(test, BorderLayout.CENTER);
...
}

//main
...
}

//public class Test2{
public class Test2 extends JPanel {

//JPanel test2 = new JPanel();

Test2(){
...
}

http to https through .htaccess

To redirect http://example.com or http://www.example.com to https://www.example.com in a simple way, you can use the following Rule in htaccess :

RewriteEngine on

RewriteCond %{HTTPS} off
RewriteCond www.%{HTTP_HOST} ^(?:www\.)?(www\..+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [NE,L,R]

[Tested]

%{REQUEST_SCHEME} variable is available since apache 2.4 , this variable contains the value of requested scheme (http or https), on apache 2.4 you can use the following rule :

RewriteEngine on


RewriteCond %{REQUEST_SCHEME} ^http$
RewriteCond %{HTTP_HOST} ^(www\.)?(.+)$ [NC]
RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [NE,L,R]

How to center a Window in Java?

Note that both the setLocationRelativeTo(null) and Tookit.getDefaultToolkit().getScreenSize() techniques work only for the primary monitor. If you are in a multi-monitor environment, you may need to get information about the specific monitor the window is on before doing this kind of calculation.

Sometimes important, sometimes not...

See GraphicsEnvironment javadocs for more info on how to get this.

How to print a double with two decimals in Android?

For Displaying digit upto two decimal places there are two possibilities - 1) Firstly, you only want to display decimal digits if it's there. For example - i) 12.10 to be displayed as 12.1, ii) 12.00 to be displayed as 12. Then use-

DecimalFormat formater = new DecimalFormat("#.##"); 

2) Secondly, you want to display decimal digits irrespective of decimal present For example -i) 12.10 to be displayed as 12.10. ii) 12 to be displayed as 12.00.Then use-

DecimalFormat formater = new DecimalFormat("0.00"); 

Example on ToggleButton

I think what are attempting is semantically same as a radio button when 1 is when one of the options is selected and 0 is the other option.

I suggest using the radio button provided by Android by default.

Here is how to use it- http://www.mkyong.com/android/android-radio-buttons-example/

and the android documentation is here-

http://developer.android.com/guide/topics/ui/controls/radiobutton.html

Thanks.

Format y axis as percent

I propose an alternative method using seaborn

Working code:

import pandas as pd
import seaborn as sns
data=np.random.rand(10,2)*100
df = pd.DataFrame(data, columns=['A', 'B'])
ax= sns.lineplot(data=df, markers= True)
ax.set(xlabel='xlabel', ylabel='ylabel', title='title')
#changing ylables ticks
y_value=['{:,.2f}'.format(x) + '%' for x in ax.get_yticks()]
ax.set_yticklabels(y_value)

enter image description here

PHP - Fatal error: Unsupported operand types

I guess you want to do this:

$total_rating_count = count($total_rating_count);
if ($total_rating_count > 0) // because you can't divide through zero
   $avg = round($total_rating_points / $total_rating_count, 1);

Why specify @charset "UTF-8"; in your CSS file?

If you're putting a <meta> tag in your css files, you're doing something wrong. The <meta> tag belongs in your html files, and tells the browser how the html is encoded, it doesn't say anything about the css, which is a separate file. You could conceivably have completely different encodings for your html and css, although I can't imagine this would be a good idea.

PHP - define constant inside a class

class Foo {
    const BAR = 'baz';
}

echo Foo::BAR;

This is the only way to make class constants. These constants are always globally accessible via Foo::BAR, but they're not accessible via just BAR.

To achieve a syntax like Foo::baz()->BAR, you would need to return an object from the function baz() of class Foo that has a property BAR. That's not a constant though. Any constant you define is always globally accessible from anywhere and can't be restricted to function call results.

jQuery - replace all instances of a character in a string

'some+multi+word+string'.replace(/\+/g, ' ');
                                   ^^^^^^

'g' = "global"

Cheers

How to display and hide a div with CSS?

Html Code :

    <a id="f">Show First content!</a>
    <br/>
    <a id="s">Show Second content!!</a>
    <div class="a">Default Content</div>
    <div class="ab hideDiv">First content</div>
    <div class="abc hideDiv">Second content</div>

Script code:

$(document).ready(function() {
    $("#f").mouseover(function(){
        $('.a,.abc').addClass('hideDiv');
        $('.ab').removeClass('hideDiv');
    }).mouseout(function() {
        $('.a').removeClass('hideDiv');
        $('.ab,.abc').addClass('hideDiv');
    });

    $("#s").mouseover(function(){
        $('.a,.ab').addClass('hideDiv');
        $('.abc').removeClass('hideDiv');
    }).mouseout(function() {
        $('.a').removeClass('hideDiv');
        $('.ab,.abc').addClass('hideDiv');
    });
});

css code:

.hideDiv
{
    display:none;
}

Tomcat is web server or application server?

Tomcat is a web server (can handle HTTP requests/responses) and web container (implements Java Servlet API, also called servletcontainer) in one. Some may call it an application server, but it is definitely not an fullfledged Java EE application server (it does not implement the whole Java EE API).

See also:

SHA-1 fingerprint of keystore certificate

[![Change the build variant then you can see the run the application which will lead to error

You have to find SHA1 code for Release Key & enter it on your Developer Console. ( for me developer console is firebase some people might use different services) To find SHA1 Code . easy way is

Go to Build --- Select Build Variant -- On the left Side Select "Release" as build variant -- now go to module settings ( or try to run project , android studio will tell you about a error and click fix error button) --- Select Signing tab --- add your release key and passwords -- now goto build types -- select release -- on signing config select your release key config -- now run your project -- now run your signing report --- you can find SHA1 under release build -- enter that sha1 code on your developer console

enter image description here

enter image description here

enter image description here

That's it

Swift - encode URL

let Url = URL(string: urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? "")

Accessing a local website from another computer inside the local network in IIS 7

do not turn off firewall, Go Control Panel\System and Security\Windows Firewall then Advanced settings then Inbound Rules->From right pan choose New Rule-> Port-> TCP and type in port number 80 then give a name in next window, that's it.

What is the convention for word separator in Java package names?

The official naming conventions aren't that strict, they don't even 'forbid' camel case notation except for prefix (com in your example).

But I personally would avoid upper case letters and hyphenations, even numbers. I'd choose com.stackoverflow.mypackage like Bragboy suggested too.

(hyphenations '-' are not legal in package names)

EDIT

Interesting - the language specification has something to say about naming conventions too.

In Chapter 7.7 Unique Package Names we see examples with package names that consist of upper case letters (so CamelCase notation would be OK) and they suggest to replace hyphonation by an underscore ("mary-lou" -> "mary_lou") and prefix java keywords with an underscore ("com.example.enum" -> "com.example._enum")

Some more examples for upper case letters in package names can be found in chapter 6.8.1 Package Names.

How do I correctly upgrade angular 2 (npm) to the latest version?

Alternative approach using npm-upgrade:

  1. npm i -g npm-upgrade

Go to your project folder

  1. npm-upgrade check

It will ask you if you wish to upgrade the package, select Yes

That's simple

IsNullOrEmpty with Object

The following code is perfectly fine and the right way (most exact, concise, and clear) to check if an object is null:

object obj = null;

//...

if (obj == null)
{
    // Do something
}

String.IsNullOrEmpty is a method existing for convenience so that you don't have to write the comparison code yourself:

private bool IsNullOrEmpty(string input)
{
    return input == null || input == string.Empty;
}

Additionally, there is a String.IsNullOrWhiteSpace method checking for null and whitespace characters, such as spaces, tabs etc.

How do I implement Toastr JS?

This is a simple way to do it!

<link href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/css/toastr.css" rel="stylesheet"/>
<script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.0.1/js/toastr.js"></script>
<script>
function notificationme(){
toastr.options = {
            "closeButton": false,
            "debug": false,
            "newestOnTop": false,
            "progressBar": true,
            "preventDuplicates": true,
            "onclick": null,
            "showDuration": "100",
            "hideDuration": "1000",
            "timeOut": "5000",
            "extendedTimeOut": "1000",
            "showEasing": "swing",
            "hideEasing": "linear",
            "showMethod": "show",
            "hideMethod": "hide"
        };
toastr.info('MY MESSAGE!');
}
</script>

Parsing a JSON string in Ruby

It looks like a JSON string. You can use one of many JSON libraries and it's as simple as doing:

JSON.parse(string)

Changing button text onclick

Or more simple without having to name the element (with 'button' element):

<button onclick="toggleLog(this)">Stop logs</button>

and script :

var bWriteLog = true;

function toggleLog(elt) {

  bWriteLog = !bWriteLog;
  elt.innerHTML = bWriteLog ? 'Stop logs' : 'Watch logs';
}

Creating a chart in Excel that ignores #N/A or blank cells

You can use the function "=IF(ISERROR(A1);0;A1)" this will show zero if the cell A1 contains an errore or the real value if it doesn't.

How to disable HTML button using JavaScript?

Try the following:

document.getElementById("id").setAttribute("disabled", "disabled");

Polling the keyboard (detect a keypress) in python


import sys
import select

def heardEnter():
    i,o,e = select.select([sys.stdin],[],[],0.0001)
    for s in i:
        if s == sys.stdin:
            input = sys.stdin.readline()
            return True
    return False

How to change background and text colors in Sublime Text 3

I had the same issue. Sublime3 no longer shows all of the installed packages when you choose Show Packages from the Preferences Menu.

To customise a colour scheme do the following (UNIX):

  • Locate your SublimeText packages directory under the directory which SublimeText is installed in (in my setup this was /opt/sublime/Packages)
  • Open "Color Scheme - Default.sublime-package"
  • Choose the colour scheme which is closest to your requirements and copy it
  • From Sublime Text choose Preferences - Browse Packages - User
  • Paste the colour scheme you copied earlier here and rename it. It should now show up on your "Preferences - Color Scheme" menu under "User"
  • Follow the instructions at the link you previously mentioned to make the changes you require (Sublime 2 -changing background color based on file type?)

--- EDIT ---

For Mac OS X the themes are stored in zipped files so although the preferences file shows them as being in Packages/Color Scheme - Default/ they don't appear in that directory unless you extract them.

  • They can be extracted using the Package Resource Viewer (See this answer for how to install and use the Package Resource Viewer).
  • Search for Color Scheme in the Package Extractor (should give options for Color Scheme Default and Color Scheme legacy)
  • Extract the one you want. It will now be available at users/UserName/Library/Application Support/Sublime Text 3/Packages/Color Scheme - Default (or Legacy)
  • Make a copy of the scheme you want to modify, edit as needed and save it
  • Add or change the line in user preferences which points to the color scheme

for example

"color_scheme": "Packages/Color Scheme - Legacy/myTheme.tmTheme"

Laravel Controller Subfolder routing

php artisan make:controller admin/CategoryController

Here admin is sub directory under app/Http/Controllers and CategoryController is controller you want to create inside directory

Is there a Mutex in Java?

Each object's lock is little different from Mutex/Semaphore design. For example there is no way to correctly implement traversing linked nodes with releasing previous node's lock and capturing next one. But with mutex it is easy to implement:

Node p = getHead();
if (p == null || x == null) return false;
p.lock.acquire();  // Prime loop by acquiring first lock.
// If above acquire fails due to interrupt, the method will
//   throw InterruptedException now, so there is no need for
//   further cleanup.
for (;;) {
Node nextp = null;
boolean found;
try { 
 found = x.equals(p.item); 
 if (!found) { 
   nextp = p.next; 
   if (nextp != null) { 
     try {      // Acquire next lock 
                //   while still holding current 
       nextp.lock.acquire(); 
     } 
     catch (InterruptedException ie) { 
      throw ie;    // Note that finally clause will 
                   //   execute before the throw 
     } 
   } 
 } 
}finally {     // release old lock regardless of outcome 
   p.lock.release();
} 

Currently, there is no such class in java.util.concurrent, but you can find Mutext implementation here Mutex.java. As for standard libraries, Semaphore provides all this functionality and much more.

How can JavaScript save to a local file?

If you are using FireFox you can use the File HandleAPI

https://developer.mozilla.org/en-US/docs/Web/API/File_Handle_API

I had just tested it out and it works!

Scale an equation to fit exact page width

\begin{equation}
\resizebox{.9\hsize}{!}{$A+B+C+D+E+F+G+H+I+J+K+L+M+N+O+P+Q+R+S+T+U+V+W+X+Y+Z$}
\end{equation}

or

\begin{equation}
\resizebox{.8\hsize}{!}{$A+B+C+D+E+F+G+H+I+J+K+L+M+N+O+P+Q+R+S+T+U+V+W+X+Y+Z$}
\end{equation}

Equivalent of LIMIT for DB2

Here's the solution I came up with:

select FIELD from TABLE where FIELD > LASTVAL order by FIELD fetch first N rows only;

By initializing LASTVAL to 0 (or '' for a text field), then setting it to the last value in the most recent set of records, this will step through the table in chunks of N records.

Reading Excel files from C#

ExcelMapper is an open source tool (http://code.google.com/p/excelmapper/) that can be used to read Excel worksheets as Strongly Typed Objects. It supports both xls and xlsx formats.

Why should a Java class implement comparable?

Most of the examples above show how to reuse an existing comparable object in the compareTo function. If you would like to implement your own compareTo when you want to compare two objects of the same class, say an AirlineTicket object that you would like to sort by price(less is ranked first), followed by number of stopover (again, less is ranked first), you would do the following:

class AirlineTicket implements Comparable<Cost>
{
    public double cost;
    public int stopovers;
    public AirlineTicket(double cost, int stopovers)
    {
        this.cost = cost; this.stopovers = stopovers ;
    }

    public int compareTo(Cost o)
    {
        if(this.cost != o.cost)
          return Double.compare(this.cost, o.cost); //sorting in ascending order. 
        if(this.stopovers != o.stopovers)
          return this.stopovers - o.stopovers; //again, ascending but swap the two if you want descending
        return 0;            
    }
}

Fastest way to count number of occurrences in a Python list

You can use pandas, by transforming the list to a pd.Series then simply use .value_counts()

import pandas as pd
a = ['1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '7', '7', '7', '10', '10']
a_cnts = pd.Series(a).value_counts().to_dict()

Input  >> a_cnts["1"], a_cnts["10"]
Output >> (6, 2)

How to copy data to clipboard in C#

For console projects in a step-by-step fashion, you'll have to first add the System.Windows.Forms reference. The following steps work in Visual Studio Community 2013 with .NET 4.5:

  1. In Solution Explorer, expand your console project.
  2. Right-click References, then click Add Reference...
  3. In the Assemblies group, under Framework, select System.Windows.Forms.
  4. Click OK.

Then, add the following using statement in with the others at the top of your code:

using System.Windows.Forms;

Then, add either of the following Clipboard.SetText statements to your code:

Clipboard.SetText("hello");
// OR
Clipboard.SetText(helloString);

And lastly, add STAThreadAttribute to your Main method as follows, to avoid a System.Threading.ThreadStateException:

[STAThreadAttribute]
static void Main(string[] args)
{
  // ...
}

SQL - Select first 10 rows only?

SELECT *  
  FROM (SELECT ROW_NUMBER () OVER (ORDER BY user_id) user_row_no, a.* FROM temp_emp a)  
 WHERE user_row_no > 1 and user_row_no <11  

This worked for me.If i may,i have few useful dbscripts that you can have look at

Useful Dbscripts

IE and Edge fix for object-fit: cover;

You can use this js code. Just change .post-thumb img with your img.

$('.post-thumb img').each(function(){           // Note: {.post-thumb img} is css selector of the image tag
    var t = $(this),
        s = 'url(' + t.attr('src') + ')',
        p = t.parent(),
        d = $('<div></div>');
    t.hide();
    p.append(d);
    d.css({
        'height'                : 260,          // Note: You can change it for your needs
        'background-size'       : 'cover',
        'background-repeat'     : 'no-repeat',
        'background-position'   : 'center',
        'background-image'      : s
    });
});

How do I resize a Google Map with JavaScript after it has loaded?

If you're using Google Maps v2, call checkResize() on your map after resizing the container. link

UPDATE

Google Maps JavaScript API v2 was deprecated in 2011. It is not available anymore.

Data binding in React

With the new feature called Hooks from the React team which makes functional components to handle state changes.. your question can be solved easily

import React, { useState, useEffect } from 'react'
import ReactDOM from 'react-dom';

const Demo = props =>{
    const [text, setText] = useState("there");
    return props.logic(text, setText);
};

const App = () => {
    const [text, setText] = useState("hello");

    const componentDidMount = () =>{
        setText("hey");
    };
    useEffect(componentDidMount, []);

    const logic = (word, setWord) => (
        <div>
            <h1>{word}</h1>
            <input type="text" value={word} onChange={e => setWord(e.target.value)}></input>
            <h1>{text}</h1>
            <input type="text" value={text} onChange={e => setText(e.target.value)}></input>
        </div>
    );
    return <Demo logic={logic} />;
};

ReactDOM.render(<App />,document.getElementById("root"));

Mod of negative number is melting my brain

Here's my one liner for positive integers, based on this answer:

usage:

(-7).Mod(3); // returns 2

implementation:

static int Mod(this int a, int n) => (((a %= n) < 0) ? n : 0) + a;

VBA: Selecting range by variables

I ran into something similar - I wanted to create a range based on some variables. Using the Worksheet.Cells did not work directly since I think the cell's values were passed to Range.

This did work though:

Range(Cells(1, 1).Address(), Cells(lastRow, lastColumn).Address()).Select

That took care of converting the cell's numerical location to what Range expects, which is the A1 format.

CMake output/build directory

As of CMake Wiki:

CMAKE_BINARY_DIR if you are building in-source, this is the same as CMAKE_SOURCE_DIR, otherwise this is the top level directory of your build tree

Compare these two variables to determine if out-of-source build was started

Consider marking event handler as 'passive' to make the page more responsive

For those stuck with legacy issues, find the line throwing the error and add {passive: true} - eg:

this.element.addEventListener(t, e, !1)

becomes

this.element.addEventListener(t, e, { passive: true} )

Inheriting from a template class in c++

For understanding templates, it's of huge advantage to get the terminology straight because the way you speak about them determines the way to think about them.

Specifically, Area is not a template class, but a class template. That is, it is a template from which classes can be generated. Area<int> is such a class (it's not an object, but of course you can create an object from that class in the same ways you can create objects from any other class). Another such class would be Area<char>. Note that those are completely different classes, which have nothing in common except for the fact that they were generated from the same class template.

Since Area is not a class, you cannot derive the class Rectangle from it. You only can derive a class from another class (or several of them). Since Area<int> is a class, you could, for example, derive Rectangle from it:

class Rectangle:
  public Area<int>
{
  // ...
};

Since Area<int> and Area<char> are different classes, you can even derive from both at the same time (however when accessing members of them, you'll have to deal with ambiguities):

class Rectangle:
  public Area<int>,
  public Area<char>
{
  // ...
};

However you have to specify which classed to derive from when you define Rectangle. This is true no matter whether those classes are generated from a template or not. Two objects of the same class simply cannot have different inheritance hierarchies.

What you can do is to make Rectangle a template as well. If you write

template<typename T> class Rectangle:
  public Area<T>
{
  // ...
};

You have a template Rectangle from which you can get a class Rectangle<int> which derives from Area<int>, and a different class Rectangle<char> which derives from Area<char>.

It may be that you want to have a single type Rectangle so that you can pass all sorts of Rectangle to the same function (which itself doesn't need to know the Area type). Since the Rectangle<T> classes generated by instantiating the template Rectangle are formally independent of each other, it doesn't work that way. However you can make use of multiple inheritance here:

class Rectangle // not inheriting from any Area type
{
  // Area independent interface
};

template<typename T> class SpecificRectangle:
  public Rectangle,
  public Area<T>
{
  // Area dependent stuff
};

void foo(Rectangle&); // A function which works with generic rectangles

int main()
{
  SpecificRectangle<int> intrect;
  foo(intrect);

  SpecificRectangle<char> charrect;
  foo(charrect);
}

If it is important that your generic Rectangle is derived from a generic Area you can do the same trick with Area too:

class Area
{
  // generic Area interface
};

class Rectangle:
  public virtual Area // virtual because of "diamond inheritance"
{
  // generic rectangle interface
};

template<typename T> class SpecificArea:
  public virtual Area
{
  // specific implementation of Area for type T
};

template<typename T> class SpecificRectangle:
  public Rectangle, // maybe this should be virtual as well, in case the hierarchy is extended later
  public SpecificArea<T> // no virtual inheritance needed here
{
  // specific implementation of Rectangle for type T
};

Background color of text in SVG

No this is not possible, SVG elements do not have background-... presentation attributes.

To simulate this effect you could draw a rectangle behind the text attribute with fill="green" or something similar (filters). Using JavaScript you could do the following:

var ctx = document.getElementById("the-svg"),
textElm = ctx.getElementById("the-text"),
SVGRect = textElm.getBBox();

var rect = document.createElementNS("http://www.w3.org/2000/svg", "rect");
    rect.setAttribute("x", SVGRect.x);
    rect.setAttribute("y", SVGRect.y);
    rect.setAttribute("width", SVGRect.width);
    rect.setAttribute("height", SVGRect.height);
    rect.setAttribute("fill", "yellow");
    ctx.insertBefore(rect, textElm);

Scanner vs. BufferedReader

I suggest to use BufferedReader for reading text. Scanner hides IOException while BufferedReader throws it immediately.

Print an ArrayList with a for-each loop

Your code works. If you don't have any output, you may have "forgotten" to add some values to the list:

// add values
list.add("one");
list.add("two");

// your code
for (String object: list) {
    System.out.println(object);
}

How do I use TensorFlow GPU?

Follow this tutorial Tensorflow GPU I did it and it works perfect.

Attention! - install version 9.0! newer version is not supported by Tensorflow-gpu

Steps:

  1. Uninstall your old tensorflow
  2. Install tensorflow-gpu pip install tensorflow-gpu
  3. Install Nvidia Graphics Card & Drivers (you probably already have)
  4. Download & Install CUDA
  5. Download & Install cuDNN
  6. Verify by simple program

from tensorflow.python.client import device_lib print(device_lib.list_local_devices())

Does Ruby have a string.startswith("abc") built in method?

If this is for a non-Rails project, I'd use String#index:

"foobar".index("foo") == 0  # => true

Getting the last revision number in SVN?

<?php
    $url = 'your repository here';
    $output = `svn info $url`;
    echo "<pre>$output</pre>";
?>

You can get the output in XML like so:

$output = `svn info $url --xml`;

If there is an error then the output will be directed to stderr. To capture stderr in your output use thusly:

$output = `svn info $url 2>&1`;

Can two applications listen to the same port?

If at least one of the remote IPs is already known, static and dedicated to talk only to one of your apps, you may use iptables rule (table nat, chain PREROUTING) to redirect incomming traffic from this address to "shared" local port to any other port where the appropriate application actually listen.

Socket accept - "Too many open files"

I had the same problem and I wasn't bothering to check the return values of the close() calls. When I started checking the return value, the problem mysteriously vanished.

I can only assume an optimisation glitch of the compiler (gcc in my case), is assuming that close() calls are without side effects and can be omitted if their return values aren't used.

jQuery: how to trigger anchor link's click event

$(":button").click(function () {                
                $("#anchor_google")[0].click();
            });
  1. First, find the button by type(using ":") if id is not given.
  2. Second,find the anchor tag by id or in some other tag like div and $("#anchor_google")[0] returns the DOM object.

Import JavaScript file and call functions using webpack, ES6, ReactJS

import * as utils from './utils.js'; 

If you do the above, you will be able to use functions in utils.js as

utils.someFunction()

How to generate random float number in C

This generates a random float between two floats.

float RandomFloat(float min, float max){
   return ((max - min) * ((float)rand() / RAND_MAX)) + min;
}

Nginx location priority

There is a handy online tool for testing location priority now:
location priority testing online

TypeError: 'undefined' is not an object

I'm not sure how you could just check if something isn't undefined and at the same time get an error that it is undefined. What browser are you using?

You could check in the following way (extra = and making length a truthy evaluation)

if (typeof(sub.from) !== 'undefined' && sub.from.length) {

[update]

I see that you reset sub and thereby reset sub.from but fail to re check if sub.from exist:

for (var i = 0; i < sub.from.length; i++) {//<== assuming sub.from.exist
            mainid = sub.from[i]['id'];
            var sub = afcHelper_Submissions[mainid]; // <== re setting sub

My guess is that the error is not on the if statement but on the for(i... statement. In Firebug you can break automatically on an error and I guess it'll break on that line (not on the if statement).

Drop columns whose name contains a specific string from pandas DataFrame

the shortest way to do is is :

resdf = df.filter(like='Test',axis=1)

How to fast-forward a branch to head?

To anyone that wants to Fast Forward they are not on to another remote branch (including itself) without checking out that branch, you can do:

git fetch origin master:other

This basically fast forwards the index of other to origin/master if you are not on other branch. You can fast forward multiple branches this way.

If you working on another branch for some time, and wanted to update stale branches from remote to their respective head:

git fetch origin master:master other:other etc:etc

Add new item in existing array in c#.net

I agree with Ed. C# does not make this easy the way VB does with ReDim Preserve. Without a collection, you'll have to copy the array into a larger one.

Replacing Pandas or Numpy Nan with a None to use with MysqlDB

After stumbling around, this worked for me:

df = df.astype(object).where(pd.notnull(df),None)

Shrink a YouTube video to responsive width

I used the CSS in the accepted answer here for my responsive YouTube videos - worked great right up until YouTube updated their system around the start of August 2015. The videos on YouTube are the same dimensions but for whatever reason the CSS in the accepted answer now letterboxes all our videos. Black bands across top and bottom.

I've tickered around with the sizes and settled on getting rid of the top padding and changing the bottom padding to 56.45%. Seems to look good.

.videowrapper {
    position: relative;
    padding-bottom: 56.45%;
    height: 0;
}

JSON forEach get Key and Value

Try something like this:

var prop;
for(prop in obj) {
    if(!obj.hasOwnProperty(prop)) continue;

    console.log(prop + " - "+ obj[prop]);
}

how to put focus on TextBox when the form load?

I solved my problem with changing "TabIndex" property of TextBox. I set 0 for TextBox that I want to focus it on Form when the program start.

SQL - Query to get server's IP address

It's in the @@SERVERNAME variable;

SELECT @@SERVERNAME;

How to reliably open a file in the same directory as a Python script

To quote from the Python documentation:

As initialized upon program startup, the first item of this list, path[0], is the directory containing the script that was used to invoke the Python interpreter. If the script directory is not available (e.g. if the interpreter is invoked interactively or if the script is read from standard input), path[0] is the empty string, which directs Python to search modules in the current directory first. Notice that the script directory is inserted before the entries inserted as a result of PYTHONPATH.

sys.path[0] is what you are looking for.

How to initialize a dict with keys from a list and empty value in Python?

nobody cared to give a dict-comprehension solution ?

>>> keys = [1,2,3,5,6,7]
>>> {key: None for key in keys}
{1: None, 2: None, 3: None, 5: None, 6: None, 7: None}

Optional Parameters in Go?

No -- neither. Per the Go for C++ programmers docs,

Go does not support function overloading and does not support user defined operators.

I can't find an equally clear statement that optional parameters are unsupported, but they are not supported either.

Python: How to get stdout after running os.system?

If all you need is the stdout output, then take a look at subprocess.check_output():

import subprocess

batcmd="dir"
result = subprocess.check_output(batcmd, shell=True)

Because you were using os.system(), you'd have to set shell=True to get the same behaviour. You do want to heed the security concerns about passing untrusted arguments to your shell.

If you need to capture stderr as well, simply add stderr=subprocess.STDOUT to the call:

result = subprocess.check_output([batcmd], stderr=subprocess.STDOUT)

to redirect the error output to the default output stream.

If you know that the output is text, add text=True to decode the returned bytes value with the platform default encoding; use encoding="..." instead if that codec is not correct for the data you receive.

Jackson with JSON: Unrecognized field, not marked as ignorable

When we are generating getters and setters, specially which starts with 'is' keyword, IDE generally removes the 'is'. e.g.

private boolean isActive;

public void setActive(boolean active) {
   isActive = active;
}

public isActive(){
   return isActive;
}

In my case, i just changed the getter and setter.

private boolean isActive;

public void setIsActive(boolean active) {
   isActive = active;
}

public getIsActive(){
   return isActive;
}

And it was able to recognize the field.

linux script to kill java process

Use jps to list running java processes. The command returns the process id along with the main class. You can use kill command to kill the process with the returned id or use following one liner script.

kill $(jps | grep <MainClass> | awk '{print $1}')

MainClass is a class in your running java program which contains the main method.

Converting any object to a byte array in java

Use serialize and deserialize methods in SerializationUtils from commons-lang.

How do I extract text that lies between parentheses (round brackets)?

Regular expressions might be the best tool here. If you are not famililar with them, I recommend you install Expresso - a great little regex tool.

Something like:

Regex regex = new Regex("\\((?<TextInsideBrackets>\\w+)\\)");
string incomingValue = "Username (sales)";
string insideBrackets = null;
Match match = regex.Match(incomingValue);
if(match.Success)
{
    insideBrackets = match.Groups["TextInsideBrackets"].Value;
}

How to return a specific element of an array?

(Edited.) There are two reasons why it doesn't compile: You're missing a semi-colon at the end of this statement:

array3[i]=e1

Also the findOut method doesn't return any value if the array length is 0. Adding a return 0; at the end of the method will make it compile. I've no idea if that will make it do what you want though, as I've no idea what you want it to do.

What is the effect of extern "C" in C++?

This answer is for the impatient/ have deadlines to meet to, only a part/simple explanation is below:

  • in C++, you can have same name in class via overloading (for example, since they are all same name can't be exported as-is from dll, etc.) solution to these problems is they are converted to different strings (called symbols), symbols accounts the name of function, also the arguments, so each of these functions even with same name, can be uniquely identified (also called, name mangling)
  • in C, you don't have overloading, the function name is unique (so, a separate string for identifying the a function name uniquely is not required, so symbol is function name itself)

So
in C++, with name mangling uniquely identities each function
in C, even without name mangling uniquely identities each function

To change the behaviour of C++, that is, to specify that name mangling should not happen for a particular function, you can use extern "C" before the function name, for whatever reason, like exporting a function with a specific name from a dll, for use by its clients.

Read other answers, for more detailed/more correct answers.

How to resolve git status "Unmerged paths:"?

Another way of dealing with this situation if your files ARE already checked in, and your files have been merged (but not committed, so the merge conflicts are inserted into the file) is to run:

git reset

This will switch to HEAD, and tell git to forget any merge conflicts, and leave the working directory as is. Then you can edit the files in question (search for the "Updated upstream" notices). Once you've dealt with the conflicts, you can run

git add -p

which will allow you to interactively select which changes you want to add to the index. Once the index looks good (git diff --cached), you can commit, and then

git reset --hard

to destroy all the unwanted changes in your working directory.

Open a new tab on button click in AngularJS

You should use the $location service

Angular docs:

tooltips for Button

both <button> tag and <input type="button"> accept a title attribute..

What's a good IDE for Python on Mac OS X?

Have tried many different (Kate, Eclipse, Scite, Vim, Komodo): each one have some glitches, either limited functions, or slow and unresponsive. Final choice after many years: Emacs + ropemacs + flymake. Rope project file open dialog is extremely quick. Rope refactoring and code assist functions are super helpful. Flymake shows syntax mistakes. Emacs is the most configurable editor. I am very happy with this config. Python related part of config is here: public.halogen-dg.com browser/alex-emacs-settings/configs/cfg_python.el

Add a auto increment primary key to existing table in oracle

Snagged from Oracle OTN forums

Use alter table to add column, for example:

alter table tableName add(columnName NUMBER);

Then create a sequence:

CREATE SEQUENCE SEQ_ID
START WITH 1
INCREMENT BY 1
MAXVALUE 99999999
MINVALUE 1
NOCYCLE;

and, the use update to insert values in column like this

UPDATE tableName SET columnName = seq_test_id.NEXTVAL

iPhone is not available. Please reconnect the device

If you are connecting it with a cable, clean the build folder, run it on the simulator, and then run it again immediately on your phone.

If you are using it without a cable, make sure the Wi-Fi connection is exactly the same on both your PC and your phone or turn the personal hotspot on your phone and connect your PC to the hotspot to make sure they're using the exact same connection.

Listing files in a specific "folder" of a AWS S3 bucket

As other have already said, everything in S3 is an object. To you, it may be files and folders. But to S3, they're just objects.

If you don't need objects which end with a '/' you can safely delete them e.g. via REST api or AWS Java SDK (I assume you have write access). You will not lose "nested files" (there no files, so you will not lose objects whose names are prefixed with the key you delete)

AmazonS3 amazonS3 = AmazonS3ClientBuilder.standard().withCredentials(new ProfileCredentialsProvider()).withRegion("region").build();
amazonS3.deleteObject(new DeleteObjectRequest("my-bucket", "users/<user-id>/contacts/<contact-id>/"));

Please note that I'm using ProfileCredentialsProvider so that my requests are not anonymous. Otherwise, you will not be able to delete an object. I have my AWS keep key stored in ~/.aws/credentials file.

How to change port number for apache in WAMP

Change port number for Xampp Go to the file C:\xampp\apache\conf\httpd.conf

#Listen 12.34.56.78:80
Listen 80

Change 80 to 82

as

#Listen 12.34.56.78:82
Listen 82

now your url will be

http://localhost:82

How to delete from select in MySQL?

DELETE 
  p1
  FROM posts AS p1 
CROSS JOIN (
  SELECT ID FROM posts GROUP BY id HAVING COUNT(id) > 1
) AS p2
USING (id)

Why do I keep getting Delete 'cr' [prettier/prettier]?

I am using git+vscode+windows+vue, and after read the eslint document: https://eslint.org/docs/rules/linebreak-style

Finally fix it by:

add *.js text eol=lf to .gitattributes

then run vue-cli-service lint --fix

Changing the image source using jQuery

For more information. I try setting src attribute with attr method in jquery for ad image using the syntax for example: $("#myid").attr('src', '/images/sample.gif');

This solution is useful and it works but if changing the path change also the path for image and not working.

I've searching for resolve this issue but not found nothing.

The solution is putting the '\' at the beginning the path: $("#myid").attr('src', '\images/sample.gif');

This trick is very useful for me and I hope it is useful for other.

MySql Inner Join with WHERE clause

You are using two WHERE clauses but only one is allowed. Use it like this:

SELECT table1.f_id FROM table1
INNER JOIN table2 ON table2.f_id = table1.f_id
WHERE
  table1.f_com_id = '430'
  AND table1.f_status = 'Submitted'
  AND table2.f_type = 'InProcess'

How to build a 'release' APK in Android Studio?

Click \Build\Select Build Variant... in Android Studio. And choose release.

Assigning strings to arrays of characters

You can use this:

yylval.sval=strdup("VHDL + Volcal trance...");

Where yylval is char*. strdup from does the job.

Free Rest API to retrieve current datetime as string (timezone irrelevant)

If you're using Rails, you can just make an empty file in the public folder and use ajax to get that. Then parse the headers for the Date header. Files in the Public folder bypass the Rails stack, and so have lower latency.

Reference - What does this error mean in PHP?

Warning: Illegal string offset 'XXX'

This happens when you try to access an array element with the square bracket syntax, but you're doing this on a string, and not on an array, so the operation clearly doesn't make sense.

Example:

$var = "test";
echo $var["a_key"];

If you think the variable should be an array, see where it comes from and fix the problem there.

How to get values from selected row in DataGrid for Windows Form Application?

You could just use

DataGridView1.CurrentRow.Cells["ColumnName"].Value

Remove duplicates from dataframe, based on two columns A,B, keeping row with max value in another column C

You can do this simply by using pandas drop duplicates function

df.drop_duplicates(['A','B'],keep= 'last')

How to properly and completely close/reset a TcpClient connection?

You have to close the stream before closing the connection:

tcpClient.GetStream().Close();
tcpClient.Close();

Closing the client does not close the stream.

JPA eager fetch does not join

If you use EclipseLink instead of Hibernate you can optimize your queries by "query hints". See this article from the Eclipse Wiki: EclipseLink/Examples/JPA/QueryOptimization.

There is a chapter about "Joined Reading".

What is the difference between attribute and property?

Delphi used properties and they have found their way into .NET (because it has the same architect).

In Delphi they are often used in combination with runtime type information such that the integrated property editor can be used to set the property in designtime.

Properties are not always related to fields. They can be functions that possible have side effects (but of course that is very bad design).

DateTime.Now.ToShortDateString(); replace month and day

this.TextBox3.Text = DateTime.Now.ToString("MM.dd.yyyy");

How to create Custom Ratings bar in Android

You can try this rating bar with much better animations

SmileyRating

enter image description here

Add Keypair to existing EC2 instance

For Elasticbeanstalk environments, you can apply a key-value pair to a running instance like this:

  • Create a key-value pair from EC2 -> Key Pairs (Under NETWORK & SECURITY tab)
  • Go to Elasticbeanstalk and click on your application
  • Go to configuration page and modify security settings
  • Choose your EC2 key pair and click Apply
  • Click confirm to confirm the update. It will terminate the environment and apply the key value to your environment.

nginx error:"location" directive is not allowed here in /etc/nginx/nginx.conf:76

Since your server already includes the sites-enabled folder ( notice the include /etc/nginx/sites-enabled/* line ), then you better use that.

  1. Create a file inside /etc/nginx/sites-available and call it whatever you want, I'll call it django since it's a djanog server

    sudo touch /etc/nginx/sites-available/django
    
  2. Then create a symlink that points to it

    sudo ln -s /etc/nginx/sites-available/django /etc/nginx/sites-enabled
    
  3. Then edit that file with whatever file editor you use, vim or nano or whatever and create the server inside it

    server {
        # hostname or ip or multiple separated by spaces
        server_name localhost example.com 192.168.1.1; #change to your setting
        location / {
            root /home/techcee/scrapbook/local/lib/python2.7/site-packages/django/__init__.pyc/;
        }
    }
    
  4. Restart or reload nginx settings

    sudo service nginx reload
    

Note I believe that your configuration like this probably won't work yet because you need to pass it to a fastcgi server or something, but at least this is how you could create a valid server

How to set a time zone (or a Kind) of a DateTime value?

You can try this as well, it is easy to implement

TimeZone time2 = TimeZone.CurrentTimeZone;
DateTime test = time2.ToUniversalTime(DateTime.Now);
var singapore = TimeZoneInfo.FindSystemTimeZoneById("Singapore Standard Time");
var singaporetime = TimeZoneInfo.ConvertTimeFromUtc(test, singapore);

Change the text to which standard time you want to change.

Use TimeZone feature of C# to implement.

C++: constructor initializer for arrays

Ideas from a twisted mind :

class mytwistedclass{
static std::vector<int> initVector;
mytwistedclass()
{
    //initialise with initVector[0] and then delete it :-)
}

};

now set this initVector to something u want to before u instantiate an object. Then your objects are initialized with your parameters.

What is the difference between mocking and spying when using Mockito?

Spy can be useful when you want to create unit tests for legacy code.

I have created a runable example here https://www.surasint.com/mockito-with-spy/ , I copy some of it here.

If you have something like this code:

public void transfer(  DepositMoneyService depositMoneyService, WithdrawMoneyService withdrawMoneyService, 
             double amount, String fromAccount, String toAccount){
    withdrawMoneyService.withdraw(fromAccount,amount);
    depositMoneyService.deposit(toAccount,amount);
}

You may don't need spy because you can just mock DepositMoneyService and WithdrawMoneyService.

But with some, legacy code, dependency is in the code like this:

    public void transfer(String fromAccount, String toAccount, double amount){

        this.depositeMoneyService = new DepositMoneyService();
        this.withdrawMoneyService = new WithdrawMoneyService();

        withdrawMoneyService.withdraw(fromAccount,amount);
        depositeMoneyService.deposit(toAccount,amount);
    }

Yes, you can change to the first code but then API is changed. If this method is being used by many places, you have to change all of them.

Alternative is that you can extract the dependency out like this:

    public void transfer(String fromAccount, String toAccount, double amount){
        this.depositeMoneyService = proxyDepositMoneyServiceCreator();
        this.withdrawMoneyService = proxyWithdrawMoneyServiceCreator();

        withdrawMoneyService.withdraw(fromAccount,amount);
        depositeMoneyService.deposit(toAccount,amount);
    }
    DepositMoneyService proxyDepositMoneyServiceCreator() {
        return new DepositMoneyService();
    }

    WithdrawMoneyService proxyWithdrawMoneyServiceCreator() {
        return new WithdrawMoneyService();
    }

Then you can use the spy the inject the dependency like this:

DepositMoneyService mockDepositMoneyService = mock(DepositMoneyService.class);
        WithdrawMoneyService mockWithdrawMoneyService = mock(WithdrawMoneyService.class);

    TransferMoneyService target = spy(new TransferMoneyService());

    doReturn(mockDepositMoneyService)
            .when(target).proxyDepositMoneyServiceCreator();

    doReturn(mockWithdrawMoneyService)
            .when(target).proxyWithdrawMoneyServiceCreator();

More detail in the link above.

All ASP.NET Web API controllers return 404

One thing I ran into was having my configurations registered in the wrong order in my GLobal.asax file for instance:

Right Order:

AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);

Wrong Order:

AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
WebApiConfig.Register(GlobalConfiguration.Configuration);

Just saying, this was my problem and changing the order is obvious, but sometimes overlooked and can cause much frustration.

Using Image control in WPF to display System.Drawing.Bitmap

According to http://khason.net/blog/how-to-use-systemdrawingbitmap-hbitmap-in-wpf/

   [DllImport("gdi32")]
   static extern int DeleteObject(IntPtr o);

   public static BitmapSource loadBitmap(System.Drawing.Bitmap source)
   {
       IntPtr ip = source.GetHbitmap();
       BitmapSource bs = null;
       try
       {
           bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, 
              IntPtr.Zero, Int32Rect.Empty, 
              System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
       }
       finally
       {
           DeleteObject(ip);
       }

       return bs;
   }

It gets System.Drawing.Bitmap (from WindowsBased) and converts it into BitmapSource, which can be actually used as image source for your Image control in WPF.

image1.Source = YourUtilClass.loadBitmap(SomeBitmap);

Error - replacement has [x] rows, data has [y]

TL;DR ...and late to the party, but that short explanation might help future googlers..

In general that error message means that the replacement doesn't fit into the corresponding column of the dataframe.

A minimal example:

df <- data.frame(a = 1:2); df$a <- 1:3

throws the error

Error in $<-.data.frame(*tmp*, a, value = 1:3) : replacement has 3 rows, data has 2

which is clear, because the vector a of df has 2 entries (rows) whilst the vector we try to replace it has 3 entries (rows).

SVN (Subversion) Problem "File is scheduled for addition, but is missing" - Using Versions

Adding a file, and then deleting it is the kind of operation that's considered an error - and so SVN is telling you. You told it to expect some file data and then don't supply it when you commit, the red lights flash and the sirens go off!

The answer is to undo your add, alternatively commit the file and then use 'svn rm' to remove it from the filesystem and the repo.

WPF Button with Image

You want to do something like this instead:

<Button>
    <StackPanel>
        <Image Source="Pictures/apple.jpg" />
        <TextBlock>Disconnect from Server</TextBlock>
    </StackPanel>
</Button>

symfony 2 No route found for "GET /"

The problem is that you don't have a route for /. Change your definition to this:

ShopMyShopBundle_homepage:
    pattern:  /
    defaults: { _controller: ShopMyShopBundle:Main:index }
    requirements:
        _method:  GET

"Comparison method violates its general contract!"

Just because this is what I got when I Googled this error, my problem was that I had

if (value < other.value)
  return -1;
else if (value >= other.value)
  return 1;
else
  return 0;

the value >= other.value should (obviously) actually be value > other.value so that you can actually return 0 with equal objects.

How to split one string into multiple strings separated by at least one space in bash shell?

(A) To split a sentence into its words (space separated) you can simply use the default IFS by using

array=( $string )


Example running the following snippet

#!/bin/bash

sentence="this is the \"sentence\"   'you' want to split"
words=( $sentence )

len="${#words[@]}"
echo "words counted: $len"

printf "%s\n" "${words[@]}" ## print array

will output

words counted: 8
this
is
the
"sentence"
'you'
want
to
split

As you can see you can use single or double quotes too without any problem

Notes:
-- this is basically the same of mob's answer, but in this way you store the array for any further needing. If you only need a single loop, you can use his answer, which is one line shorter :)
-- please refer to this question for alternate methods to split a string based on delimiter.


(B) To check for a character in a string you can also use a regular expression match.
Example to check for the presence of a space character you can use:

regex='\s{1,}'
if [[ "$sentence" =~ $regex ]]
    then
        echo "Space here!";
fi

Detecting the onload event of a window opened with window.open

If the pop-up's document is from a different domain, this is simply not possible.

Update April 2015: I was wrong about this: if you own both domains, you can use window.postMessage and the message event in pretty much all browsers that are relevant today.

If not, there's still no way you'll be able to make this work cross-browser without some help from the document being loaded into the pop-up. You need to be able to detect a change in the pop-up that occurs once it has loaded, which could be a variable that JavaScript in the pop-up page sets when it handles its own load event, or if you have some control of it you could add a call to a function in the opener.

How do I use installed packages in PyCharm?

You should never need to modify the path directly, either through environment variables or sys.path. Whether you use the os (ex. apt-get), or pip in a virtualenv, packages will be installed to a location already on the path.

In your example, GNU Radio is installed to the system Python 2's standard site-packages location, which is already in the path. Pointing PyCharm at the correct interpreter is enough; if it isn't there is something else wrong that isn't apparent. It may be that /usr/bin/python does not point to the same interpreter that GNU Radio was installed in; try pointing specifically at the python2.7 binary. Or, PyCharm used to be somewhat bad at detecting packages; File > Invalidate Caches > Invalidate and Restart would tell it to rescan.

This answer will cover how you should set up a project environment, install packages in different scenarios, and configure PyCharm. I refer multiple times to the Python Packaging User Guide, written by the same group that maintains the official Python packaging tools.


The correct way to develop a Python application is with a virtualenv. Packages and version are installed without affecting the system or other projects. PyCharm has a built-in interface to create a virtualenv and install packages. Or you can create it from the command line and then point PyCharm at it.

$ cd MyProject
$ python2 -m virtualenv env
$ . env/bin/activate
$ pip install -U pip setuptools  # get the latest versions
$ pip install flask  # install other packages

In your PyCharm project, go to File > Settings > Project > Project Interpreter. If you used virtualenvwrapper or PyCharm to create the env, then it should show up in the menu. If not, click the gear, choose Add Local, and locate the Python binary in the env. PyCharm will display all the packages in the selected env.

choose an env

manually locate env


In some cases, such as with GNU Radio, there is no package to install with pip, the package was installed system-wide when you install the rest of GNU Radio (ex. apt-get install gnuradio). In this case, you should still use a virtualenv, but you'll need to make it aware of this system package.

$ python2 -m virtualenv --system-site-packages env

Unfortunately it looks a little messy, because all system packages will now appear in your env, but they are just links, you can still safely install or upgrade packages without affecting the system.


In some cases, you will have multiple local packages you're developing, and will want one project to use the other package. In this case you might think you have to add the local package to the other project's path, but this is not the case. You should install your package in development mode. All this requires is adding a setup.py file to your package, which will be required anyway to properly distribute and deploy the package later.

Minimal setup.py for your first project:

from setuptools import setup, find_packages

setup(
    name='mypackage',
    version='0.1',
    packages=find_packages(),
)

Then install it in your second project's env:

$ pip install -e /path/to/first/project

How to print full stack trace in exception?

I usually use the .ToString() method on exceptions to present the full exception information (including the inner stack trace) in text:

catch (MyCustomException ex)
{
    Debug.WriteLine(ex.ToString());
}

Sample output:

ConsoleApplication1.MyCustomException: some message .... ---> System.Exception: Oh noes!
   at ConsoleApplication1.SomeObject.OtherMethod() in C:\ConsoleApplication1\SomeObject.cs:line 24
   at ConsoleApplication1.SomeObject..ctor() in C:\ConsoleApplication1\SomeObject.cs:line 14
   --- End of inner exception stack trace ---
   at ConsoleApplication1.SomeObject..ctor() in C:\ConsoleApplication1\SomeObject.cs:line 18
   at ConsoleApplication1.Program.DoSomething() in C:\ConsoleApplication1\Program.cs:line 23
   at ConsoleApplication1.Program.Main(String[] args) in C:\ConsoleApplication1\Program.cs:line 13

Where is Xcode's build folder?

I wondered the same myself. I found that under File(menu) there is an item "Project Settings". It opens a dialog box with 3 choices: "Default Location", "Project-relative Location", and "Custom location" "Project-relative" puts the build products in the project folder, like before. This is not in the Preferences menu and must be set every time a project is created. Hope this helps.

Clearing content of text file using php

//create a file handler by opening the file
$myTextFileHandler = @fopen("filelist.txt","r+");

//truncate the file to zero
//or you could have used the write method and written nothing to it
@ftruncate($myTextFileHandler, 0);

//use location header to go back to index.html
header("Location:index.html");

I don't exactly know where u want to show the result.

Nested JSON: How to add (push) new items to an object?

push is an Array method, for json object you may need to define it

this should do it:

library[title] = {"foregrounds" : foregrounds,"backgrounds" : backgrounds};

Reading e-mails from Outlook with Python through MAPI

Sorry for my bad English. Checking Mails using Python with MAPI is easier,

outlook =win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
folder = outlook.Folders[5]
Subfldr = folder.Folders[5]
messages_REACH = Subfldr.Items
message = messages_REACH.GetFirst()

Here we can get the most first mail into the Mail box, or into any sub folder. Actually, we need to check the Mailbox number & orientation. With the help of this analysis we can check each mailbox & its sub mailbox folders.

Similarly please find the below code, where we can see, the last/ earlier mails. How we need to check.

`outlook =win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
folder = outlook.Folders[5]
Subfldr = folder.Folders[5]
messages_REACH = Subfldr.Items
message = messages_REACH.GetLast()`

With this we can get most recent email into the mailbox. According to the above mentioned code, we can check our all mail boxes, & its sub folders.

What are all codecs and formats supported by FFmpeg?

The formats and codecs supported by your build of ffmpeg can vary due the version, how it was compiled, and if any external libraries, such as libx264, were supported during compilation.

Formats (muxers and demuxers):

List all formats:

ffmpeg -formats

Display options specific to, and information about, a particular muxer:

ffmpeg -h muxer=matroska

Display options specific to, and information about, a particular demuxer:

ffmpeg -h demuxer=gif

Codecs (encoders and decoders):

List all codecs:

ffmpeg -codecs

List all encoders:

ffmpeg -encoders

List all decoders:

ffmpeg -decoders

Display options specific to, and information about, a particular encoder:

ffmpeg -h encoder=mpeg4

Display options specific to, and information about, a particular decoder:

ffmpeg -h decoder=aac

Reading the results

There is a key near the top of the output that describes each letter that precedes the name of the format, encoder, decoder, or codec:

$ ffmpeg -encoders
[…]
Encoders:
 V..... = Video
 A..... = Audio
 S..... = Subtitle
 .F.... = Frame-level multithreading
 ..S... = Slice-level multithreading
 ...X.. = Codec is experimental
 ....B. = Supports draw_horiz_band
 .....D = Supports direct rendering method 1
 ------
[…]
 V.S... mpeg4                MPEG-4 part 2

In this example V.S... indicates that the encoder mpeg4 is a Video encoder and supports Slice-level multithreading.

Also see

What is a codec and how does it differ from a format?

Easy way to pull latest of all git submodules

Git for windows 2.6.3:

git submodule update --rebase --remote

Java switch statement multiple cases

One Object Oriented option to replace excessively large switch and if/else constructs is to use a Chain of Responsibility Pattern to model the decision making.

Chain of Responsibility Pattern

The chain of responsibility pattern allows the separation of the source of a request from deciding which of the potentially large number of handlers for the request should action it. The class representing the chain role channels the requests from the source along the list of handlers until a handler accepts the request and actions it.

Here is an example implementation that is also Type Safe using Generics.

import java.util.ArrayList;
import java.util.List;

/**
* Generic enabled Object Oriented Switch/Case construct
* @param <T> type to switch on
*/
public class Switch<T extends Comparable<T>>
{
    private final List<Case<T>> cases;

    public Switch()
    {
        this.cases = new ArrayList<Case<T>>();
    }

    /**
     * Register the Cases with the Switch
     * @param c case to register
     */
    public void register(final Case<T> c) { this.cases.add(c); }

    /**
     * Run the switch logic on some input
     * @param type input to Switch on
     */
    public void evaluate(final T type)
    {
        for (final Case<T> c : this.cases)
        {
            if (c.of(type)) { break; }
        }
    }

    /**
     * Generic Case condition
     * @param <T> type to accept
     */
    public static interface Case<T extends Comparable<T>>
    {
        public boolean of(final T type);
    }

    public static abstract class AbstractCase<T extends Comparable<T>> implements Case<T>
    {
        protected final boolean breakOnCompletion;

        protected AbstractCase()
        {
            this(true);
        }

        protected AbstractCase(final boolean breakOnCompletion)
        {
            this.breakOnCompletion = breakOnCompletion;
        }
    }

    /**
     * Example of standard "equals" case condition
     * @param <T> type to accept
     */
    public static abstract class EqualsCase<T extends Comparable<T>> extends AbstractCase<T>
    {
        private final T type;

        public EqualsCase(final T type)
        {
            super();
            this.type = type;
        }

        public EqualsCase(final T type, final boolean breakOnCompletion)
        {
            super(breakOnCompletion);
            this.type = type;
        }
    }

    /**
     * Concrete example of an advanced Case conditional to match a Range of values
     * @param <T> type of input
     */
    public static abstract class InRangeCase<T extends Comparable<T>> extends AbstractCase<T>
    {
        private final static int GREATER_THAN = 1;
        private final static int EQUALS = 0;
        private final static int LESS_THAN = -1;
        protected final T start;
        protected final T end;

        public InRangeCase(final T start, final T end)
        {
            this.start = start;
            this.end = end;
        }

        public InRangeCase(final T start, final T end, final boolean breakOnCompletion)
        {
            super(breakOnCompletion);
            this.start = start;
            this.end = end;
        }

        private boolean inRange(final T type)
        {
            return (type.compareTo(this.start) == EQUALS || type.compareTo(this.start) == GREATER_THAN) &&
                    (type.compareTo(this.end) == EQUALS || type.compareTo(this.end) == LESS_THAN);
        }
    }

    /**
     * Show how to apply a Chain of Responsibility Pattern to implement a Switch/Case construct
     *
     * @param args command line arguments aren't used in this example
     */
    public static void main(final String[] args)
    {
        final Switch<Integer> integerSwitch = new Switch<Integer>();
        final Case<Integer> case1 = new EqualsCase<Integer>(1)
        {
            @Override
            public boolean of(final Integer type)
            {
                if (super.type.equals(type))
                {
                    System.out.format("Case %d, break = %s\n", type, super.breakOnCompletion);
                    return super.breakOnCompletion;
                }
                else
                {
                    return false;
                }
            }
        };
        integerSwitch.register(case1);
        // more instances for each matching pattern, granted this will get verbose with lots of options but is just
        // and example of how to do standard "switch/case" logic with this pattern.
        integerSwitch.evaluate(0);
        integerSwitch.evaluate(1);
        integerSwitch.evaluate(2);


        final Switch<Integer> inRangeCaseSwitch = new Switch<Integer>();
        final Case<Integer> rangeCase = new InRangeCase<Integer>(5, 100)
        {
            @Override
            public boolean of(final Integer type)
            {
                if (super.inRange(type))
                {
                    System.out.format("Case %s is between %s and %s, break = %s\n", type, this.start, this.end, super.breakOnCompletion);
                    return super.breakOnCompletion;
                }
                else
                {
                    return false;
                }
            }
        };
        inRangeCaseSwitch.register(rangeCase);
        // run some examples
        inRangeCaseSwitch.evaluate(0);
        inRangeCaseSwitch.evaluate(10);
        inRangeCaseSwitch.evaluate(200);

        // combining both types of Case implementations
        integerSwitch.register(rangeCase);
        integerSwitch.evaluate(1);
        integerSwitch.evaluate(10);

    }
}

This is just a quick straw man that I whipped up in a few minutes, a more sophisticated implementation might allow for some kind of Command Pattern to be injected into the Case implementations instances to make it more of a call back IoC style.

Once nice thing about this approach is that Switch/Case statements are all about side affects, this encapsulates the side effects in Classes so they can be managed, and re-used better, it ends up being more like Pattern Matching in a Functional language and that isn't a bad thing.

I will post any updates or enhancements to this Gist on Github.

Does a finally block always get executed in Java?

The finally block is always executed unless there is abnormal program termination, either resulting from a JVM crash or from a call to System.exit(0).

On top of that, any value returned from within the finally block will override the value returned prior to execution of the finally block, so be careful of checking all exit points when using try finally.

Mongoose: CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"

For the record: I had this error trying to fill a subdocument in a wrong way:

{
[CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"]
message: 'Cast to ObjectId failed for value "[object Object]" at path "_id"',
name: 'CastError',
type: 'ObjectId',
path: '_id'
value:
  [ { timestamp: '2014-07-03T00:23:45-04:00',
  date_start: '2014-07-03T00:23:45-04:00',
  date_end: '2014-07-03T00:23:45-04:00',
  operation: 'Deactivation' } ],
}

look ^ value is an array containing an object: wrong!

Explanation: I was sending data from php to a node.js API in this way:

$history = json_encode(
array(
  array(
  'timestamp'  => date('c', time()),
  'date_start' => date('c', time()),
  'date_end'   => date('c', time()),
  'operation'  => 'Deactivation'
)));

As you can see $history is an array containing an array. That's why mongoose try to fill _id (or any other field) with an array instead than a Scheme.ObjectId (or any other data type). The following works:

$history = json_encode(
array(
  'timestamp'  => date('c', time()),
  'date_start' => date('c', time()),
  'date_end'   => date('c', time()),
  'operation'  => 'Deactivation'
));

load scripts asynchronously

You might find this wiki article interesting : http://ajaxpatterns.org/On-Demand_Javascript

It explains how and when to use such technique.

how to implement a pop up dialog box in iOS

For Swift 3 & Swift 4 :

Since UIAlertView is deprecated, there is the good way for display Alert on Swift 3

let alertController = UIAlertController(title: NSLocalizedString("No network connection",comment:""), message: NSLocalizedString("connected to the internet to use this app.",comment:""), preferredStyle: .alert)
let defaultAction = UIAlertAction(title:     NSLocalizedString("Ok", comment: ""), style: .default, handler: { (pAlert) in
                //Do whatever you want here
        })
alertController.addAction(defaultAction)
self.present(alertController, animated: true, completion: nil)

Deprecated :

This is the swift version inspired by the checked response :

Display AlertView :

   let alert = UIAlertView(title: "No network connection", 
                           message: "You must be connected to the internet to use this app.", delegate: nil, cancelButtonTitle: "Ok")
    alert.delegate = self
    alert.show()

Add the delegate to your view controller :

class AgendaViewController: UIViewController, UIAlertViewDelegate

When user click on button, this code will be executed :

func alertView(alertView: UIAlertView, clickedButtonAtIndex buttonIndex: Int) {


}

How to change the default port of mysql from 3306 to 3360

When server first starts the my.ini may not be created where everyone has stated. I was able to find mine in C:\Documents and Settings\All Users\Application Data\MySQL\MySQL Server 5.6

This location has the defaults for every setting.

# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
#
[client]

# pipe
# socket=0.0
port=4306  !!!!!!!!!!!!!!!!!!!Change this!!!!!!!!!!!!!!!!!

[mysql]
no-beep

default-character-set=utf8

How to uninstall with msiexec using product id guid without .msi file present

The good thing is, this one is really easily and deterministically to analyze: Either, the msi package is really not installed on the system or you're doing something wrong. Of course the correct call is:

msiexec /x {A4BFF20C-A21E-4720-88E5-79D5A5AEB2E8}

(Admin rights needed of course- With curly braces without any quotes here- quotes are only needed, if paths or values with blank are specified in the commandline.)
If the message is: "This action is only valid for products that are currently installed", then this is true. Either the package with this ProductCode is not installed or there is a typo.

To verify where the fault is:

  1. First try to right click on the (probably) installed .msi file itself. You will see (besides "Install" and "Repair") an Uninstall entry. Click on that.
    a) If that uninstall works, your msi has another ProductCode than you expect (maybe you have the wrong WiX source or your build has dynamic logging where the ProductCode changes).
    b) If that uninstall gives the same "...only valid for products already installed" the package is not installed (which is obviously a precondition to be able to uninstall it).

  2. If 1.a) was the case, you can look for the correct ProductCode of your package, if you open your msi file with Orca, Insted or another editor/tool. Just google for them. Look there in the table with the name "Property" and search for the string "ProductCode" in the first column. In the second column there is the correct value.

There are no other possibilities.

Just a suggestion for the used commandline: I would add at least the "/qb" for a simple progress bar or "/qn" parameter (the latter for complete silent uninstall, but makes only sense if you are sure it works).

What's better at freeing memory with PHP: unset() or $var = null

I created a new performance test for unset and =null, because as mentioned in the comments the here written has an error (the recreating of the elements). I used arrays, as you see it didn't matter now.

<?php
$arr1 = array();
$arr2 = array();
for ($i = 0; $i < 10000000; $i++) {
    $arr1[$i] = 'a';
    $arr2[$i] = 'a';
}

$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    $arr1[$i] = null;
}
$elapsed = microtime(true) - $start;

echo 'took '. $elapsed .'seconds<br>';

$start = microtime(true);
for ($i = 0; $i < 10000000; $i++) {
    unset($arr2[$i]);
}
$elapsed = microtime(true) - $start;

echo 'took '. $elapsed .'seconds<br>';

But i can only test it on an PHP 5.5.9 server, here the results: - took 4.4571571350098 seconds - took 4.4425978660583 seconds

I prefer unset for readability reasons.

regex with space and letters only?

use this expression

var RegExpression = /^[a-zA-Z\s]*$/;  

for more refer this http://tools.netshiftmedia.com

How to increment variable under DOS?

A little bit late for the party, but it's an interessting question.

You can write your own inc.bat for incrementing a number.
It can increment numbers from 0 to 9998.

@echo off
if "%1"==":inc" goto :increment

call %0 :inc %counter0%
set counter0=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter1%
set counter1=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter2%
set counter2=%_cnt%
if %_overflow%==0 goto :exit 

call %0 :inc %counter3%
set counter3=%_cnt%
goto :exit

:increment
set _overflow=0
set _cnt=%2

if "%_cnt%"=="" set _cnt=0

if %_cnt%==9 goto :overflow
if %_cnt%==8 set _cnt=9
if %_cnt%==7 set _cnt=8
if %_cnt%==6 set _cnt=7
if %_cnt%==5 set _cnt=6
if %_cnt%==4 set _cnt=5
if %_cnt%==3 set _cnt=4
if %_cnt%==2 set _cnt=3
if %_cnt%==1 set _cnt=2
if %_cnt%==0 set _cnt=1
goto :exit

:overflow
set _cnt=0
set _overflow=1
goto :exit

:exit
set count=%counter3%%counter2%%counter1%%counter0%

A sample for using it is here

@echo off
set counter0=0
set counter1=
set counter2=
set counter3=

:loop
call inc.bat
echo %count%
if not %count%==250 goto :loop

How can I get the "network" time, (from the "Automatic" setting called "Use network-provided values"), NOT the time on the phone?

Get the library from http://commons.apache.org/net/download_net.cgi

//NTP server list: http://tf.nist.gov/tf-cgi/servers.cgi
public static final String TIME_SERVER = "time-a.nist.gov";

public static long getCurrentNetworkTime() {
    NTPUDPClient timeClient = new NTPUDPClient();
    InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);
    TimeInfo timeInfo = timeClient.getTime(inetAddress);
    //long returnTime = timeInfo.getReturnTime();   //local device time
    long returnTime = timeInfo.getMessage().getTransmitTimeStamp().getTime();   //server time

    Date time = new Date(returnTime);
    Log.d(TAG, "Time from " + TIME_SERVER + ": " + time);

    return returnTime;
}

getReturnTime() is same as System.currentTimeMillis().

getReceiveTimeStamp() or getTransmitTimeStamp() method should be used.

You can see the difference after setting system time to 1 hour ago.

local time :
System.currentTimeMillis()
timeInfo.getReturnTime()
timeInfo.getMessage().getOriginateTimeStamp().getTime()

NTP server time :
timeInfo.getMessage().getReceiveTimeStamp().getTime()
timeInfo.getMessage().getTransmitTimeStamp().getTime()

How to Change Font Size in drawString Java

Because you can't count on a particular font being available, a good approach is to derive a new font from the current font. This gives you the same family, weight, etc. just larger...

Font currentFont = g.getFont();
Font newFont = currentFont.deriveFont(currentFont.getSize() * 1.4F);
g.setFont(newFont);

You can also use TextAttribute.

Map<TextAttribute, Object> attributes = new HashMap<>();

attributes.put(TextAttribute.FAMILY, currentFont.getFamily());
attributes.put(TextAttribute.WEIGHT, TextAttribute.WEIGHT_SEMIBOLD);
attributes.put(TextAttribute.SIZE, (int) (currentFont.getSize() * 1.4));
myFont = Font.getFont(attributes);

g.setFont(myFont);

The TextAttribute method often gives one even greater flexibility. For example, you can set the weight to semi-bold, as in the example above.

One last suggestion... Because the resolution of monitors can be different and continues to increase with technology, avoid adding a specific amount (such as getSize()+2 or getSize()+4) and consider multiplying instead. This way, your new font is consistently proportional to the "current" font (getSize() * 1.4), and you won't be editing your code when you get one of those nice 4K monitors.

How do I add target="_blank" to a link within a specified div?

/* here are two different ways to do this */
//using jquery:
$(document).ready(function(){
  $('#link_other a').attr('target', '_blank');
});

// not using jquery
window.onload = function(){
  var anchors = document.getElementById('link_other').getElementsByTagName('a');
  for (var i=0; i<anchors.length; i++){
    anchors[i].setAttribute('target', '_blank');
  }
}
// jquery is prettier. :-)

You could also add a title tag to notify the user that you are doing this, to warn them, because as has been pointed out, it's not what users expect:

$('#link_other a').attr('target', '_blank').attr('title','This link will open in a new window.');

Convert a String to int?

let my_u8: u8 = "42".parse::<u8>().unwrap();
let my_u32: u32 = "42".parse::<u32>().unwrap();

// or, to be safe, match the `Err`
match "foobar".parse::<i32>() {
  Ok(n) => do_something_with(n),
  Err(e) => weep_and_moan(),
}

str::parse::<u32> returns a Result<u32, core::num::ParseIntError> and Result::unwrap "Unwraps a result, yielding the content of an Ok [or] panics if the value is an Err, with a panic message provided by the Err's value."

str::parse is a generic function, hence the type in angle brackets.

SQL Not Like Statement not working

If WPP.COMMENT contains NULL, the condition will not match.

This query:

SELECT  1
WHERE   NULL NOT LIKE '%test%'

will return nothing.

On a NULL column, both LIKE and NOT LIKE against any search string will return NULL.

Could you please post relevant values of a row which in your opinion should be returned but it isn't?

Simple Java Client/Server Program

There is a fundamental concept of IP routing: You must have a unique IP address if you want your machine to be reachable via the Internet. This is called a "Public IP Address". "www.whatismyipaddress.com" will give you this. If your server is behind some default gateway, IP packets would reach you via that router. You can not be reached via your private IP address from the outside world. You should note that private IP addresses of client and server may be same as long as their corresponding default gateways have different addresses (that's why IPv4 is still in effect) I guess you're trying to ping from your private address of your client to the public IP address of the server (provided by whatismyipaddress.com). This is not feasible. In order to achieve this, a mapping from private to public address is required, a process called Network Address Translation or NAT in short. This is configured in Firewall or Router. You can create your own private network (say via wifi). In this case, since your client and server would be on the same logical network, no private to public address translation would be required and hence you can communicate using your private IP addresses only.

Blurry text after using CSS transform: scale(); in Chrome

Instead of

transform: scale(1.5);

using

zoom : 150%;

fixes the text blurring problem in Chrome.

Converting a JToken (or string) to a given Type

var i2 = JsonConvert.DeserializeObject(obj["id"].ToString(), type);

throws a parsing exception due to missing quotes around the first argument (I think). I got it to work by adding the quotes:

var i2 = JsonConvert.DeserializeObject("\"" + obj["id"].ToString() + "\"", type);

how to bold words within a paragraph in HTML/CSS?

Although your answer has many solutions I think this is a great way to save lines of code. Try using spans which is great for situations like yours.

  1. Create a class for making any item bold. So for paragraph text it would be
span.bold(This name can be anything do not include parenthesis) {
   font-weight: bold;
}
  1. In your html you can access that class like by using the span tags and adding a class of bold or whatever name you have chosen

Debug assertion failed. C++ vector subscript out of range

this type of error usually occur when you try to access data through the index in which data data has not been assign. for example

//assign of data in to array
for(int i=0; i<10; i++){
   arr[i]=i;
}
//accessing of data through array index
for(int i=10; i>=0; i--){
cout << arr[i];
}

the code will give error (vector subscript out of range) because you are accessing the arr[10] which has not been assign yet.

Select values of checkbox group with jQuery

Use .map() (adapted from the example at http://api.jquery.com/map/):

var values = $("input[name='user_group[]']:checked").map(function(index,domElement) {
    return $(domElement).val();
});

#1130 - Host ‘localhost’ is not allowed to connect to this MySQL server

Use this in your my.ini under

[mysqldump]
    user=root
    password=anything

Instantiating a generic type

You basically have two choices:

1.Require an instance:

public Navigation(T t) {     this("", "", t); } 

2.Require a class instance:

public Navigation(Class<T> c) {     this("", "", c.newInstance()); } 

You could use a factory pattern, but ultimately you'll face this same issue, but just push it elsewhere in the code.

How do I correct "Commit Failed. File xxx is out of date. xxx path not found."

I've just had similar problem but without any branching or merging to cause the problem. My workaround was to:

  • svn export my working folder (including unversioned files) to a temp folder.
  • rename the working folder a backup.
  • svn checkout the trunk.
  • copy all folder from temp export folder over new working folder.
  • svn commit.

All seems fine now.

HTML Upload MAX_FILE_SIZE does not appear to work

It's only supposed to send the information to the server. The reason that it must preceed the file field is that it has to come before the file payload in the request for the server to be able to use it to check the size of the upload.

How the value is used on the server depends on what you use to take care of the upload. The code is supposedly intended for a specific upload component that specifically looks for that value.

It seems that the built in upload support in PHP is one to use this field value.

Excel VBA Copy a Range into a New Workbook

Modify to suit your specifics, or make more generic as needed:

Private Sub CopyItOver()
  Set NewBook = Workbooks.Add
  Workbooks("Whatever.xlsx").Worksheets("output").Range("A1:K10").Copy
  NewBook.Worksheets("Sheet1").Range("A1").PasteSpecial (xlPasteValues)
  NewBook.SaveAs FileName:=NewBook.Worksheets("Sheet1").Range("E3").Value
End Sub

How to convert an Instant to a date format?

Instant i = Instant.ofEpochSecond(cal.getTime);

Read more here and here

How to calculate modulus of large numbers?

Just provide another implementation of Jason's answer by C.

After discussing with my classmates, based on Jason's explanation, I like the recursive version more if you don't care about the performance very much:

For example:

#include<stdio.h>

int mypow( int base, int pow, int mod ){
    if( pow == 0 ) return 1;
    if( pow % 2 == 0 ){
        int tmp = mypow( base, pow >> 1, mod );
        return tmp * tmp % mod;
    }
    else{
        return base * mypow( base, pow - 1, mod ) % mod;
    }
}

int main(){
    printf("%d", mypow(5,55,221));
    return 0;
}

How do you check current view controller class in Swift?

if let index = self.navigationController?.viewControllers.index(where: { $0 is MyViewController }) {
            let vc = self.navigationController?.viewControllers[vcIndex] as! MyViewController
            self.navigationController?.popToViewController(vc, animated: true)
        } else {
            self.navigationController?.popToRootViewController(animated: true)
        }

Call PowerShell script PS1 from another PS1 script inside Powershell ISE

In order to find the location of a script, use Split-Path $MyInvocation.MyCommand.Path (make sure you use this in the script context).

The reason you should use that and not anything else can be illustrated with this example script.

## ScriptTest.ps1
Write-Host "InvocationName:" $MyInvocation.InvocationName
Write-Host "Path:" $MyInvocation.MyCommand.Path

Here are some results.

PS C:\Users\JasonAr> .\ScriptTest.ps1
InvocationName: .\ScriptTest.ps1
Path: C:\Users\JasonAr\ScriptTest.ps1

PS C:\Users\JasonAr> . .\ScriptTest.ps1
InvocationName: .
Path: C:\Users\JasonAr\ScriptTest.ps1

PS C:\Users\JasonAr> & ".\ScriptTest.ps1"
InvocationName: &
Path: C:\Users\JasonAr\ScriptTest.ps1

In PowerShell 3.0 and later you can use the automatic variable $PSScriptRoot:

## ScriptTest.ps1
Write-Host "Script:" $PSCommandPath
Write-Host "Path:" $PSScriptRoot
PS C:\Users\jarcher> .\ScriptTest.ps1
Script: C:\Users\jarcher\ScriptTest.ps1
Path: C:\Users\jarcher

shorthand c++ if else statement

The basic syntax for using ternary operator is like this:

(condition) ? (if_true) : (if_false)

For you case it is like this:

number < 0 ? bigInt.sign = 0 : bigInt.sign = 1;

Regular Expressions: Is there an AND operator?

Look at this example:

We have 2 regexps A and B and we want to match both of them, so in pseudo-code it looks like this:

pattern = "/A AND B/"

It can be written without using the AND operator like this:

pattern = "/NOT (NOT A OR NOT B)/"

in PCRE:

"/(^(^A|^B))/"

regexp_match(pattern,data)

How do I set up Eclipse/EGit with GitHub?

Install Mylyn connector for GitHub from this update site, it provides great integration: you can directly import your repositories using Import > Projects from Git > GitHub. You can set the default repository folder in Preferences > Git.

1030 Got error 28 from storage engine

Drop the problem database, then reboot mysql service (sudo service mysql restart, for example).

Android button with icon and text

This is what you really want.

<Button
       android:id="@+id/settings"
       android:layout_width="190dp"
       android:layout_height="wrap_content"
       android:layout_gravity="center_horizontal"
       android:background="@color/colorAccent"
       android:drawableStart="@drawable/ic_settings_black_24dp"
       android:paddingStart="40dp"
       android:paddingEnd="40dp"
       android:text="settings"
       android:textColor="#FFF" />

MySQL Fire Trigger for both Insert and Update

In response to @Zxaos request, since we can not have AND/OR operators for MySQL triggers, starting with your code, below is a complete example to achieve the same.

1. Define the INSERT trigger:

DELIMITER //
DROP TRIGGER IF EXISTS my_insert_trigger//
CREATE DEFINER=root@localhost TRIGGER my_insert_trigger
    AFTER INSERT ON `table`
    FOR EACH ROW

BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    -- NEW.id is an example parameter passed to the procedure but is not required
    -- if you do not need to pass anything to your procedure.
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

2. Define the UPDATE trigger

DELIMITER //
DROP TRIGGER IF EXISTS my_update_trigger//

CREATE DEFINER=root@localhost TRIGGER my_update_trigger
    AFTER UPDATE ON `table`
    FOR EACH ROW
BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

3. Define the common PROCEDURE used by both these triggers:

DELIMITER //
DROP PROCEDURE IF EXISTS procedure_to_run_processes_due_to_changes_on_table//

CREATE DEFINER=root@localhost PROCEDURE procedure_to_run_processes_due_to_changes_on_table(IN table_row_id VARCHAR(255))
READS SQL DATA
BEGIN

    -- Write your MySQL code to perform when a `table` row is inserted or updated here

END//
DELIMITER ;

You note that I take care to restore the delimiter when I am done with my business defining the triggers and procedure.

Adding maven nexus repo to my pom.xml

From maven setting reference, you can not put your username/password in a pom.xml

The repositories for download and deployment are defined by the repositories and distributionManagement elements of the POM. However, certain settings such as username and password should not be distributed along with the pom.xml. This type of information should exist on the build server in the settings.xml.

You can first add a repository in your pom and then add the username/password in the $MAVEN_HOME/conf/settings.xml:

  <servers>
    <server>
        <id>my-internal-site</id>
        <username>yourUsername</username>
        <password>yourPassword</password>
    </server>
  </servers>

Conditional statement in a one line lambda function in python?

Yes, you can use the shorthand syntax for if statements.

rate = lambda(t): (200 * exp(-t)) if t > 200 else (400 * exp(-t))

Note that you don't use explicit return statements inlambdas either.

How can I check if mysql is installed on ubuntu?

You can use tool dpkg for managing packages in Debian operating system.

Example

dpkg --get-selections | grep mysql if it's listed as installed, you got it. Else you need to get it.

CSS Classes & SubClasses

do you want to force only children to be selected? http://css.maxdesign.com.au/selectutorial/selectors_child.htm

.area1
{
        border:1px solid black;
}
.area1>.item
{
    color:red;
}
.area2
{
    border:1px solid blue;
}
.area2>.item
{
    color:blue;
}

What is the purpose of mvnw and mvnw.cmd files?

Command mvnw uses Maven that is by default downloaded to ~/.m2/wrapper on the first use.

URL with Maven is specified in each project at .mvn/wrapper/maven-wrapper.properties:

distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.3.9/apache-maven-3.3.9-bin.zip

To update or change Maven version invoke the following (remember about --non-recursive for multi-module projects):

./mvnw io.takari:maven:wrapper -Dmaven=3.3.9 

or just modify .mvn/wrapper/maven-wrapper.properties manually.

To generate wrapper from scratch using Maven (you need to have it already in PATH run:

mvn io.takari:maven:wrapper -Dmaven=3.3.9 

Binding multiple events to a listener (without JQuery)?

Cleaning up Isaac's answer:

['mousemove', 'touchmove'].forEach(function(e) {
  window.addEventListener(e, mouseMoveHandler);
});

EDIT

ES6 helper function:

function addMultipleEventListener(element, events, handler) {
  events.forEach(e => element.addEventListener(e, handler))
}

How to change file encoding in NetBeans?

The NetBeans documentation merely states a hierarchy for FileEncodingQuery (FEQ), suggesting that you can set encoding on a per-file basis:

Just for reference, this is the wiki-page regarding project-wide settings:

Dynamically load JS inside JS

You can do it using JQuery:

$.getScript("ajax/test.js", function(data, textStatus, jqxhr) {
  console.log(data); //data returned
  console.log(textStatus); //success
  console.log(jqxhr.status); //200
  console.log('Load was performed.');
});

this link should help: http://api.jquery.com/jQuery.getScript/

C# how to wait for a webpage to finish loading before continuing

I think the DocumentCompleted event of the WebBrowser control should get you where you need to go.

What is the printf format specifier for bool?

There is no format specifier for bool. You can print it using some of the existing specifiers for printing integral types or do something more fancy:

 printf("%s", x?"true":"false");

How to get the version of ionic framework?

Run from your project folder:

$ ionic info

Cordova CLI: 5.0.0
Ionic Version: 1.0.1
Ionic CLI Version: 1.6.1
Ionic App Lib Version: 0.3.3
OS: Windows 7 SP1
Node Version: v0.12.2

If your CLI is old enough, it will say "info is not a valid task" and you can use this:

$ ionic lib

Local Ionic version: 1.0.1  (C:\stuff\july21app\www\lib\ionic\version.json)
Latest Ionic version: 1.0.1  (released 2015-06-30)
* Local version up to date

Java JTable setting Column Width

With JTable.AUTO_RESIZE_OFF, the table will not change the size of any of the columns for you, so it will take your preferred setting. If it is your goal to have the columns default to your preferred size, except to have the last column fill the rest of the pane, You have the option of using the JTable.AUTO_RESIZE_LAST_COLUMN autoResizeMode, but it might be most effective when used with TableColumn.setMaxWidth() instead of TableColumn.setPreferredWidth() for all but the last column.

Once you are satisfied that AUTO_RESIZE_LAST_COLUMN does in fact work, you can experiment with a combination of TableColumn.setMaxWidth() and TableColumn.setMinWidth()

What is the use of static synchronized method in java?

In simple words a static synchronized method will lock the class instead of the object, and it will lock the class because the keyword static means: "class instead of instance".

The keyword synchronized means that only one thread can access the method at a time.
And static synchronized mean:

Only one thread can access the class at one time.

Difference between == and ===

Read more about Bitwise and Bit Shift Operators

>>      Signed right shift
>>>     Unsigned right shift

The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator >>> shifts a zero into the leftmost position,

while the leftmost position after >> depends on sign extension.

In simple words >>> always shifts a zero into the leftmost position whereas >> shifts based on sign of the number i.e. 1 for negative number and 0 for positive number.


For example try with negative as well as positive numbers.

int c = -153;
System.out.printf("%32s%n",Integer.toBinaryString(c >>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c >>>= 2));
System.out.println(Integer.toBinaryString(c <<= 2));

System.out.println();

c = 153;
System.out.printf("%32s%n",Integer.toBinaryString(c >>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c >>>= 2));
System.out.printf("%32s%n",Integer.toBinaryString(c <<= 2));

output:

11111111111111111111111111011001
11111111111111111111111101100100
  111111111111111111111111011001
11111111111111111111111101100100

                          100110
                        10011000
                          100110
                        10011000

Export a list into a CSV or TXT file in R

Check out in here, worked well for me, with no limits in the output size, no omitted elements, even beyond 1000

Exporting large lists in R as .txt or .csv

"error: assignment to expression with array type error" when I assign a struct field (C)

typedef struct{
     char name[30];
     char surname[30];
     int age;
} data;

defines that data should be a block of memory that fits 60 chars plus 4 for the int (see note)

[----------------------------,------------------------------,----]
 ^ this is name              ^ this is surname              ^ this is age

This allocates the memory on the stack.

data s1;

Assignments just copies numbers, sometimes pointers.

This fails

s1.name = "Paulo";

because the compiler knows that s1.name is the start of a struct 64 bytes long, and "Paulo" is a char[] 6 bytes long (6 because of the trailing \0 in C strings)
Thus, trying to assign a pointer to a string into a string.

To copy "Paulo" into the struct at the point name and "Rossi" into the struct at point surname.

memcpy(s1.name,    "Paulo", 6);
memcpy(s1.surname, "Rossi", 6);
s1.age = 1;

You end up with

[Paulo0----------------------,Rossi0-------------------------,0001]

strcpy does the same thing but it knows about \0 termination so does not need the length hardcoded.

Alternatively you can define a struct which points to char arrays of any length.

typedef struct {
  char *name;
  char *surname;
  int age;
} data;

This will create

[----,----,----]

This will now work because you are filling the struct with pointers.

s1.name = "Paulo";
s1.surname = "Rossi";
s1.age = 1;

Something like this

[---4,--10,---1]

Where 4 and 10 are pointers.

Note: the ints and pointers can be different sizes, the sizes 4 above are 32bit as an example.

What does <? php echo ("<pre>"); ..... echo("</pre>"); ?> mean?

here whatever we write in between the pre tags it will be interpreted same as html pre tag

ex:

<?php
echo '<pre>';
echo '
code here 
will be displayed
as it 
is 


namaste
';
echo "this line get printed in new line";
echo "</pre>";
echo "Now pre ended:";
echo "this line gets joined to above line";
?>

and content b/w 's font also changes.

Replace whitespaces with tabs in linux

You can also use astyle. I found it quite useful and it has several options too:

Tab and Bracket Options:
   If  no  indentation  option is set, the default option of 4 spaces will be used. Equivalent to -s4 --indent=spaces=4.  If no brackets option is set, the
   brackets will not be changed.

   --indent=spaces, --indent=spaces=#, -s, -s#
          Indent using # spaces per indent. Between 1 to 20.  Not specifying # will result in a default of 4 spaces per indent.

   --indent=tab, --indent=tab=#, -t, -t#
          Indent using tab characters, assuming that each tab is # spaces long.  Between 1 and 20. Not specifying # will result in a default assumption  of
          4 spaces per tab.`

php is null or empty?

As is shown in the following table, empty($foo) is equivalent to $foo==null and is_null($foo) has the same function of $foo===null. The table also shows some tricky values regarding the null comparison. (? denotes an uninitialized variables. )

         empty    is_null 
         ==null  ===null  isset   array_key_exists
      ? |   T   |   T   |   F   |   F   
   null |   T   |   T   |   F   |   T   
     "" |   T   |   F   |   T   |   T   
     [] |   T   |   F   |   T   |   T
      0 |   T   |   F   |   T   |   T      
  false |   T   |   F   |   T   |   T   
   true |   F   |   F   |   T   |   T   
      1 |   F   |   F   |   T   |   T   
     \0 |   F   |   F   |   T   |   T   

MSVCP120d.dll missing

From the comments, the problem was caused by using dlls that were built with Visual Studio 2013 in a project compiled with Visual Studio 2012. The reason for this was a third party library named the folders containing the dlls vc11, vc12. One has to be careful with any system that uses the compiler version (less than 4 digits) since this does not match the version of Visual Studio (except for Visual Studio 2010).

  • vc8 = Visual Studio 2005
  • vc9 = Visual Studio 2008
  • vc10 = Visual Studio 2010
  • vc11 = Visual Studio 2012
  • vc12 = Visual Studio 2013
  • vc14 = Visual Studio 2015
  • vc15 = Visual Studio 2017
  • vc16 = Visual Studio 2019

The Microsoft C++ runtime dlls use a 2 or 3 digit code also based on the compiler version not the version of Visual Studio.

  • MSVCP80.DLL is from Visual Studio 2005
  • MSVCP90.DLL is from Visual Studio 2008
  • MSVCP100.DLL is from Visual Studio 2010
  • MSVCP110.DLL is from Visual Studio 2012
  • MSVCP120.DLL is from Visual Studio 2013
  • MSVCP140.DLL is from Visual Studio 2015, 2017 and 2019

There is binary compatibility between Visual Studio 2015, 2017 and 2019.

Disable asp.net button after click to prevent double clicking

You can use the client-side onclick event to do that:

yourButton.Attributes.Add("onclick", "this.disabled=true;");

SQL comment header examples

-- Author: 
--
-- Original creation date: 
--
-- Description: 

Why calling react setState method doesn't mutate the state immediately?

You could try using ES7 async/await. For instance using your example:

handleChange: async function(event) {
    console.log(this.state.value);
    await this.setState({value: event.target.value});
    console.log(this.state.value);
}

ImportError: No module named model_selection

Update sklearn

conda update scikit-learn

Getting session value in javascript

If you are using VB as code behind, you have to use bracket "()" instead of square bracket "[]".

Example for VB:

<script type="text/javascript">
var accesslevel = '<%= Session("accesslevel").ToString().ToLower() %>';
</script>  

How to set the initial zoom/width for a webview

I'm working with loading images for this answer and I want them to be scaled to the device's width. I find that, for older phones with versions less than API 19 (KitKat), the behavior for Brian's answer isn't quite as I like it. It puts a lot of whitespace around some images on older phones, but works on my newer one. Here is my alternative, with help from this answer: Can Android's WebView automatically resize huge images? The layout algorithm SINGLE_COLUMN is deprecated, but it works and I feel like it is appropriate for working with older webviews.

WebSettings settings = webView.getSettings();

// Image set to width of device. (Must be done differently for API < 19 (kitkat))
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
    if (!settings.getLayoutAlgorithm().equals(WebSettings.LayoutAlgorithm.SINGLE_COLUMN))
        settings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.SINGLE_COLUMN);
} else {
    if (!settings.getLoadWithOverviewMode()) settings.setLoadWithOverviewMode(true);
    if (!settings.getUseWideViewPort()) settings.setUseWideViewPort(true);
}

val() vs. text() for textarea

The best way to set/get the value of a textarea is the .val(), .value method.

.text() internally uses the .textContent (or .innerText for IE) method to get the contents of a <textarea>. The following test cases illustrate how text() and .val() relate to each other:

var t = '<textarea>';
console.log($(t).text('test').val());             // Prints test
console.log($(t).val('too').text('test').val());  // Prints too
console.log($(t).val('too').text());              // Prints nothing
console.log($(t).text('test').val('too').val());  // Prints too

console.log($(t).text('test').val('too').text()); // Prints test

The value property, used by .val() always shows the current visible value, whereas text()'s return value can be wrong.

Concatenating two std::vectors

Here's a general purpose solution using C++11 move semantics:

template <typename T>
std::vector<T> concat(const std::vector<T>& lhs, const std::vector<T>& rhs)
{
    if (lhs.empty()) return rhs;
    if (rhs.empty()) return lhs;
    std::vector<T> result {};
    result.reserve(lhs.size() + rhs.size());
    result.insert(result.cend(), lhs.cbegin(), lhs.cend());
    result.insert(result.cend(), rhs.cbegin(), rhs.cend());
    return result;
}

template <typename T>
std::vector<T> concat(std::vector<T>&& lhs, const std::vector<T>& rhs)
{
    lhs.insert(lhs.cend(), rhs.cbegin(), rhs.cend());
    return std::move(lhs);
}

template <typename T>
std::vector<T> concat(const std::vector<T>& lhs, std::vector<T>&& rhs)
{
    rhs.insert(rhs.cbegin(), lhs.cbegin(), lhs.cend());
    return std::move(rhs);
}

template <typename T>
std::vector<T> concat(std::vector<T>&& lhs, std::vector<T>&& rhs)
{
    if (lhs.empty()) return std::move(rhs);
    lhs.insert(lhs.cend(), std::make_move_iterator(rhs.begin()), std::make_move_iterator(rhs.end()));
    return std::move(lhs);
}

Note how this differs from appending to a vector.

Creating a search form in PHP to search a database?

try this out let me know what happens.

Form:

<form action="form.php" method="post"> 
Search: <input type="text" name="term" /><br /> 
<input type="submit" value="Submit" /> 
</form> 

Form.php:

$term = mysql_real_escape_string($_REQUEST['term']);    

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'";
$r_query = mysql_query($sql);

while ($row = mysql_fetch_array($r_query)){ 
echo 'Primary key: ' .$row['PRIMARYKEY']; 
echo '<br /> Code: ' .$row['Code']; 
echo '<br /> Description: '.$row['Description']; 
echo '<br /> Category: '.$row['Category']; 
echo '<br /> Cut Size: '.$row['CutSize'];  
} 

Edit: Cleaned it up a little more.

Final Cut (my test file):

<?php
$db_hostname = 'localhost';
$db_username = 'demo';
$db_password = 'demo';
$db_database = 'demo';

// Database Connection String
$con = mysql_connect($db_hostname,$db_username,$db_password);
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db($db_database, $con);
?>

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title></title>
    </head>
    <body>
<form action="" method="post">  
Search: <input type="text" name="term" /><br />  
<input type="submit" value="Submit" />  
</form>  
<?php
if (!empty($_REQUEST['term'])) {

$term = mysql_real_escape_string($_REQUEST['term']);     

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'"; 
$r_query = mysql_query($sql); 

while ($row = mysql_fetch_array($r_query)){  
echo 'Primary key: ' .$row['PRIMARYKEY'];  
echo '<br /> Code: ' .$row['Code'];  
echo '<br /> Description: '.$row['Description'];  
echo '<br /> Category: '.$row['Category'];  
echo '<br /> Cut Size: '.$row['CutSize'];   
}  

}
?>
    </body>
</html>

Cannot uninstall angular-cli

You have to use (without @)

npm uninstall -g angular/cli

because

If you're using Angular CLI beta.28 or less, you need to uninstall angular-cli package. It should be done due to changing of package's name and scope from angular-cli to @angular/cli https://github.com/angular/angular-cli

In Python, what does dict.pop(a,b) mean?

>>> def func(a, *args, **kwargs):
...   print 'a %s, args %s, kwargs %s' % (a, args, kwargs)
... 
>>> func('one', 'two', 'three', four='four', five='five')
a one, args ('two', 'three'), kwargs {'four': 'four', 'five': 'five'}

>>> def anotherfunct(beta, *args):
...   print 'beta %s, args %s' % (beta, args)
... 
>>> def func(a, *args, **kwargs):
...   anotherfunct(a, *args)
... 
>>> func('one', 'two', 'three', four='four', five='five')
beta one, args ('two', 'three')
>>> 

jQuery - Call ajax every 10 seconds

You could try setInterval() instead:

var i = setInterval(function(){
   //Call ajax here
},10000)

How do I prevent an Android device from going to sleep programmatically?

what @eldarerathis said is correct in all aspects, the wake lock is the right way of keeping the device from going to sleep.

I don't know waht you app needs to do but it is really important that you think on how architect your app so that you don't force the phone to stay awake for more that you need, or the battery life will suffer enormously.

I would point you to this really good example on how to use AlarmManager to fire events and wake up the phone and (your app) to perform what you need to do and then go to sleep again: Alarm Manager (source: commonsware.com)

Upgrade Node.js to the latest version on Mac OS

I am able to upgrade the node using following command

nvm install node --reinstall-packages-from=node

SDK location not found. Define location with sdk.dir in the local.properties file or with an ANDROID_HOME environment variable

the best and the easiest way is to create new Android project move "app" folder from non working project to that newly made one and add the needed dependencies in the gradle of your new project and everything will work perfectly )

"Input string was not in a correct format."

Problems

There are some possible cases why the error occurs:

  1. Because textBox1.Text contains only number, but the number is too big/too small

  2. Because textBox1.Text contains:

    • a) non-number (except space in the beginning/end, - in the beginning) and/or
    • b) thousand separators in the applied culture for your code without specifying NumberStyles.AllowThousands or you specify NumberStyles.AllowThousands but put wrong thousand separator in the culture and/or
    • c) decimal separator (which should not exist in int parsing)

NOT OK Examples:

Case 1

a = Int32.Parse("5000000000"); //5 billions, too large
b = Int32.Parse("-5000000000"); //-5 billions, too small
//The limit for int (32-bit integer) is only from -2,147,483,648 to 2,147,483,647

Case 2 a)

a = Int32.Parse("a189"); //having a 
a = Int32.Parse("1-89"); //having - but not in the beginning
a = Int32.Parse("18 9"); //having space, but not in the beginning or end

Case 2 b)

NumberStyles styles = NumberStyles.AllowThousands;
a = Int32.Parse("1,189"); //not OK, no NumberStyles.AllowThousands
b = Int32.Parse("1,189", styles, new CultureInfo("fr-FR")); //not OK, having NumberStyles.AllowThousands but the culture specified use different thousand separator

Case 2 c)

NumberStyles styles = NumberStyles.AllowDecimalPoint;
a = Int32.Parse("1.189", styles); //wrong, int parse cannot parse decimal point at all!

Seemingly NOT OK, but actually OK Examples:

Case 2 a) OK

a = Int32.Parse("-189"); //having - but in the beginning
b = Int32.Parse(" 189 "); //having space, but in the beginning or end

Case 2 b) OK

NumberStyles styles = NumberStyles.AllowThousands;
a = Int32.Parse("1,189", styles); //ok, having NumberStyles.AllowThousands in the correct culture
b = Int32.Parse("1 189", styles, new CultureInfo("fr-FR")); //ok, having NumberStyles.AllowThousands and correct thousand separator is used for "fr-FR" culture

Solutions

In all cases, please check the value of textBox1.Text with your Visual Studio debugger and make sure that it has purely-acceptable numerical format for int range. Something like this:

1234

Also, you may consider of

  1. using TryParse instead of Parse to ensure that the non-parsed number does not cause you exception problem.
  2. check the result of TryParse and handle it if not true

    int val;
    bool result = int.TryParse(textbox1.Text, out val);
    if (!result)
        return; //something has gone wrong
    //OK, continue using val
    

Entity Framework: There is already an open DataReader associated with this Command

Try in your connection string to set MultipleActiveResultSets=true. This allow multitasking on database.

Server=yourserver ;AttachDbFilename=database;User Id=sa;Password=blah ;MultipleActiveResultSets=true;App=EntityFramework

That works for me ... whether your connection in app.config or you set it programmatically ... hope this helpful

How to calculate the 95% confidence interval for the slope in a linear regression model in R

Let's fit the model:

> library(ISwR)
> fit <- lm(metabolic.rate ~ body.weight, rmr)
> summary(fit)

Call:
lm(formula = metabolic.rate ~ body.weight, data = rmr)

Residuals:
    Min      1Q  Median      3Q     Max 
-245.74 -113.99  -32.05  104.96  484.81 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 811.2267    76.9755  10.539 2.29e-13 ***
body.weight   7.0595     0.9776   7.221 7.03e-09 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 

Residual standard error: 157.9 on 42 degrees of freedom
Multiple R-squared: 0.5539, Adjusted R-squared: 0.5433 
F-statistic: 52.15 on 1 and 42 DF,  p-value: 7.025e-09 

The 95% confidence interval for the slope is the estimated coefficient (7.0595) ± two standard errors (0.9776).

This can be computed using confint:

> confint(fit, 'body.weight', level=0.95)
               2.5 % 97.5 %
body.weight 5.086656 9.0324

How do I do a case-insensitive string comparison?

Assuming ASCII strings:

string1 = 'Hello'
string2 = 'hello'

if string1.lower() == string2.lower():
    print("The strings are the same (case insensitive)")
else:
    print("The strings are NOT the same (case insensitive)")

JSON string to JS object

the string in your question is not a valid json string. From json.org website:

JSON is built on two structures:

* A collection of name/value pairs. In various languages, this is 
  realized as an object, record, struct, dictionary, hash table, keyed list, or
  associative array.
* An ordered list of values. In most languages, this is realized as an
  array, vector, list, or sequence.

Basically a json string will always start with either { or [.

Then as @Andy E and @Cryo said you can parse the string with json2.js or some other libraries.

IMHO you should avoid eval because it will any javascript program, so you might incur in security issues.

Foreign Key Django Model

I would advise, it is slightly better practise to use string model references for ForeignKey relationships if utilising an app based approach to seperation of logical concerns .

So, expanding on Martijn Pieters' answer:

class Person(models.Model):
    name = models.CharField(max_length=50)
    birthday = models.DateField()
    anniversary = models.ForeignKey(
        'app_label.Anniversary', on_delete=models.CASCADE)
    address = models.ForeignKey(
        'app_label.Address', on_delete=models.CASCADE)

class Address(models.Model):
    line1 = models.CharField(max_length=150)
    line2 = models.CharField(max_length=150)
    postalcode = models.CharField(max_length=10)
    city = models.CharField(max_length=150)
    country = models.CharField(max_length=150)

class Anniversary(models.Model):
    date = models.DateField()

How to pass ArrayList of Objects from one to another activity using Intent in android?

Your arrayList:

ArrayList<String> yourArray = new ArrayList<>();

Write this code from where you want intent:

Intent newIntent = new Intent(this, NextActivity.class);
newIntent.putExtra("name",yourArray);
startActivity(newIntent);

In Next Activity:

ArrayList<String> myArray = new ArrayList<>();

Write this code in onCreate:

myArray =(ArrayList<String>)getIntent().getSerializableExtra("name");