Programs & Examples On #Android ndk

The Android Native Development Kit (NDK) is a companion tool to the Android SDK that lets you build performance-critical portions of your apps in native code or port existing libraries in C/C++ to Android. It provides headers and libraries that allow you to build activities, handle user input, use hardware sensors, access application resources, and more, when programming in C/C++.

Can't include C++ headers like vector in Android NDK

In android NDK go to android-ndk-r9b>/sources/cxx-stl/gnu-libstdc++/4.X/include in linux machines

I've found solution from the below link http://osdir.com/ml/android-ndk/2011-09/msg00336.html

Running Node.Js on Android

Dory - node.js

Great New Application
No Need to root your Phone and You Can Run your js File From anywere.

  • node.js runtime(run ES2015/ES6, ES2016 javascript and node.js APIs in android)
  • API Documents and instant code run from doc
  • syntax highlighting code editor
  • npm supports
  • linux terminal(toybox 0.7.4). node.js REPL and npm command in shell (add '--no-bin-links' option if you execute npm in /sdcard)
  • StartOnBoot / LiveReload
  • native node.js binary and npm are included. no need to be online.

Update instruction to node js 8 (async await)

  1. Download node.js v8.3.0 arm zip file and unzip.

  2. copy 'node' to android's sdcard(/sdcard or /sdcard/path/to/...)

  3. open the shell(check it out in the app's menu)

  4. cd /data/user/0/io.tmpage.dorynode/files/bin (or, just type cd && cd .. && cd files/bin )

  5. rm node

  6. cp /sdcard/node .

  7. (chmod a+x node

(https://play.google.com/store/apps/details?id=io.tempage.dorynode&hl=en)

Android Fatal signal 11 (SIGSEGV) at 0x636f7d89 (code=1). How can it be tracked down?

I've faced with SIGSEGV on Android 4.4.4 (Nexuses, Samsungs) And it turned out that fatal error was in parsing null String using DecimalFormat

 static DecimalFormat decimalFormat = new DecimalFormat("###,###.###");
 void someMethod(String value) {
...
    Number number = decimalFormat.parse(value);//value is null, SIGSEGV will happen`
...
}

On Android > 21 it was handled successfully with try/catch

Android studio, gradle and NDK

I found "gradle 1.11 com.android.tools.build:gradle:0.9.+" supports pre-build ndk now, you can just put the *.so in the dir src/main/jniLibs. when building gradle will package the ndk to the right place.

here is my project

Project:
|--src
|--|--main
|--|--|--java
|--|--|--jniLibs
|--|--|--|--armeabi
|--|--|--|--|--.so files
|--libs
|--|--other.jar

Calling a java method from c++ in Android

If it's an object method, you need to pass the object to CallObjectMethod:

jobject result = env->CallObjectMethod(obj, messageMe, jstr);

What you were doing was the equivalent of jstr.messageMe().

Since your is a void method, you should call:

env->CallVoidMethod(obj, messageMe, jstr);

If you want to return a result, you need to change your JNI signature (the ()V means a method of void return type) and also the return type in your Java code.

How to use su command over adb shell?

Well, if your phone is rooted you can run commands with the su -c command.

Here is an example of a cat command on the build.prop file to get a phone's product information.

adb shell "su -c 'cat /system/build.prop |grep "product"'"

This invokes root permission and runs the command inside the ' '.

Notice the 5 end quotes, that is required that you close ALL your end quotes or you will get an error.

For clarification the format is like this.

adb shell "su -c '[your command goes here]'"

Make sure you enter the command EXACTLY the way that you normally would when running it in shell.

Error: No toolchains found in the NDK toolchains folder for ABI with prefix: llvm

I fixed this Error by uninstalling the NDK in the SDK-Tools. So, if you don't need the NDK, uninstall it.

Why use armeabi-v7a code over armeabi code?

EABI = Embedded Application Binary Interface. It is such specifications to which an executable must conform in order to execute in a specific execution environment. It also specifies various aspects of compilation and linkage required for interoperation between toolchains used for the ARM Architecture. In this context when we speak about armeabi we speak about ARM architecture and GNU/Linux OS. Android follows the little-endian ARM GNU/Linux ABI.

armeabi application will run on ARMv5 (e.g. ARM9) and ARMv6 (e.g. ARM11). You may use Floating Point hardware if you build your application using proper GCC options like -mfpu=vfpv3 -mfloat-abi=softfp which tells compiler to generate floating point instructions for VFP hardware and enables the soft-float calling conventions. armeabi doesn't support hard-float calling conventions (it means FP registers are not used to contain arguments for a function), but FP operations in HW are still supported.

armeabi-v7a application will run on Cortex A# devices like Cortex A8, A9, and A15. It supports multi-core processors and it supports -mfloat-abi=hard. So, if you build your application using -mfloat-abi=hard, many of your function calls will be faster.

How to use adb pull command?

I don't think adb pull handles wildcards for multiple files. I ran into the same problem and did this by moving the files to a folder and then pulling the folder.

I found a link doing the same thing. Try following these steps.

How to copy selected files from Android with adb pull

[INSTALL_FAILED_NO_MATCHING_ABIS: Failed to extract native libraries, res=-113]

This is caused by a gradle dependency on some out-of-date thing which causes the error. Remove gradle dependencies until the error stops appearing. For me, it was:

implementation 'org.apache.directory.studio:org.apache.commons.io:2.4'

This line needed to be updated to a newer version such as:

api group: 'commons-io', name: 'commons-io', version: '2.6'

Where do I find old versions of Android NDK?

I came across this just now doing the same search, and found the other answers are far too specific. I also google searched for downloading android-ndk-r8 and found next to nothing. To get the correct version, I instead went here:

https://developer.android.com/ndk/downloads/index.html

And copied the link to the download I needed, and pasted it into the URL bar. There, I edited the version to reflect what I wanted (for example, I changed r8b to r8). Then I pressed enter, and the correct download began.

As long as the naming conventions remain the same, this should work across all versions.


Edit: This convention did change. Some older versions are now available in the archives. For even older versions, refer to the links provided by the answer above.

java.lang.ClassNotFoundException: Didn't find class on path: dexpathlist

I faced this Issue multiple times and they're all solved by disabling Instant Run.

What causes signal 'SIGILL'?

Make sure that all functions with non-void return type have a return statement.

While some compilers automatically provide a default return value, others will send a SIGILL or SIGTRAP at runtime when trying to leave a function without a return value.

System.loadLibrary(...) couldn't find native library in my case

This is an Android 8 update.

In earlier version of Android, to LoadLibrary native shared libraries (for access via JNI for example) I hard-wired my native code to iterate through a range of potential directory paths for the lib folder, based on the various apk installation/upgrade algorithms:

/data/data/<PackageName>/lib
/data/app-lib/<PackageName>-1/lib
/data/app-lib/<PackageName>-2/lib
/data/app/<PackageName>-1/lib
/data/app/<PackageName>-2/lib

This approach is hokey and will not work for Android 8; from https://developer.android.com/about/versions/oreo/android-8.0-changes.html you'll see that as part of their "Security" changes you now need to use sourceDir:

"You can no longer assume that APKs reside in directories whose names end in -1 or -2. Apps should use sourceDir to get the directory, and not rely on the directory format directly."

Correction, sourceDir is not the way to find your native shared libraries; use something like. Tested for Android 4.4.4 --> 8.0

// Return Full path to the directory where native JNI libraries are stored.
private static String getNativeLibraryDir(Context context) {
    ApplicationInfo appInfo = context.getApplicationInfo();
    return appInfo.nativeLibraryDir;
}

How to compile and run a C/C++ program on the Android system

You can compile your C programs with an ARM cross-compiler:

arm-linux-gnueabi-gcc -static -march=armv7-a test.c -o test

Then you can push your compiled binary file to somewhere (don't push it in to the SD card):

adb push test /data/local/tmp/test

How to get query string parameter from MVC Razor markup?

It was suggested to post this as an answer, because some other answers are giving errors like 'The name Context does not exist in the current context'.

Just using the following works:

Request.Query["queryparm1"]

Sample usage:

<a href="@Url.Action("Query",new {parm1=Request.Query["queryparm1"]})">GO</a>

Java Loop every minute

You can use Timer

Timer timer = new Timer();

timer.schedule( new TimerTask() {
    public void run() {
       // do your work 
    }
 }, 0, 60*1000);

When the times comes

  timer.cancel();

To shut it down.

Subset dataframe by multiple logical conditions of rows to remove

This answer is more meant to explain why, not how. The '==' operator in R is vectorized in a same way as the '+' operator. It matches the elements of whatever is on the left side to the elements of whatever is on the right side, per element. For example:

> 1:3 == 1:3
[1] TRUE TRUE TRUE

Here the first test is 1==1 which is TRUE, the second 2==2 and the third 3==3. Notice that this returns a FALSE in the first and second element because the order is wrong:

> 3:1 == 1:3
[1] FALSE  TRUE FALSE

Now if one object is smaller then the other object then the smaller object is repeated as much as it takes to match the larger object. If the size of the larger object is not a multiplication of the size of the smaller object you get a warning that not all elements are repeated. For example:

>  1:2 == 1:3
[1]  TRUE  TRUE FALSE
Warning message:
In 1:2 == 1:3 :
  longer object length is not a multiple of shorter object length

Here the first match is 1==1, then 2==2, and finally 1==3 (FALSE) because the left side is smaller. If one of the sides is only one element then that is repeated:

> 1:3 == 1
[1]  TRUE FALSE FALSE

The correct operator to test if an element is in a vector is indeed '%in%' which is vectorized only to the left element (for each element in the left vector it is tested if it is part of any object in the right element).

Alternatively, you can use '&' to combine two logical statements. '&' takes two elements and checks elementwise if both are TRUE:

> 1:3 == 1 & 1:3 != 2
[1]  TRUE FALSE FALSE

How to locate the Path of the current project directory in Java (IDE)?

you can get the current project path use System.getProperty("user.dir")

in that method you write Key name to get your different-different paths, and if you don't know key, you can find all property use of System.getProperties() this method is return all property with key. and you can find key name manually from it.

and write System.getProperty("KEY NAME")

and get your require path.

Launch Image does not show up in my iOS App

Do what Spectravideo328 answered and:

Try to UNCHECK the iOS 7 and later box and CHECK the iOS 6 and prior box in the asset catalog. There seems to be a bug with the iOS 7 Launch Image. (These both have the same Launch Images except for the 320x480 one)

Hope this helps, it did help for me!

How do I search for files in Visual Studio Code?

Also works in ubuntu with Ctrl+E

How to use the toString method in Java?

Whenever you access an Object (not being a String) in a String context then the toString() is called under the covers by the compiler.

This is why

Map map = new HashMap();
System.out.println("map=" + map);

works, and by overriding the standard toString() from Object in your own classes, you can make your objects useful in String contexts too.

(and consider it a black box! Never, ever use the contents for anything else than presenting to a human)

How to ping ubuntu guest on VirtualBox

Using NAT (the default) this is not possible. Bridged Networking should allow it. If bridged does not work for you (this may be the case when your network adminstration does not allow multiple IP addresses on one physical interface), you could try 'Host-only networking' instead.

For configuration of Host-only here is a quote from the vbox manual(which is pretty good). http://www.virtualbox.org/manual/ch06.html:

For host-only networking, like with internal networking, you may find the DHCP server useful that is built into VirtualBox. This can be enabled to then manage the IP addresses in the host-only network since otherwise you would need to configure all IP addresses statically.

In the VirtualBox graphical user interface, you can configure all these items in the global settings via "File" -> "Settings" -> "Network", which lists all host-only networks which are presently in use. Click on the network name and then on the "Edit" button to the right, and you can modify the adapter and DHCP settings.

Why not use tables for layout in HTML?

Layout flexibility
Imagine you're making a page with a large number of thumbnails.
DIVs:
If you put each thumbnail in a DIV, floated left, maybe 10 of them fit on a row. Make the window narrower, and BAM - it's 6 on a row, or 2, or however many fit.
TABLE:
You have to explicitly say how many cells are in a row. If the window is too narrow, the user has to scroll horizontally.

Maintainability
Same situation as above. Now you want to add three thumbnails to the third row.
DIVs:
Add them in. The layout will automatically adjust.
TABLE: Paste the new cells into the third row. Oops! Now there are too many items there. Cut some from that row and put them on the fourth row. Now there are too many items there. Cut some from that row... (etc)
(Of course, if you're generating the rows and cells with server-side scripting, this probably won't be an issue.)

Delete an element from a dictionary

I think your solution is best way to do it. But if you want another solution, you can create a new dictionary with using the keys from old dictionary without including your specified key, like this:

>>> a
{0: 'zero', 1: 'one', 2: 'two', 3: 'three'}
>>> {i:a[i] for i in a if i!=0}
{1: 'one', 2: 'two', 3: 'three'}

how to run a winform from console application?

The easiest option is to start a windows forms project, then change the output-type to Console Application. Alternatively, just add a reference to System.Windows.Forms.dll, and start coding:

using System.Windows.Forms;

[STAThread]
static void Main() {
    Application.EnableVisualStyles();
    Application.Run(new Form()); // or whatever
}

The important bit is the [STAThread] on your Main() method, required for full COM support.

Clear Cache in Android Application programmatically

Put this code in onStop() method of MainActivity

@Override
protected void onStop() {
    super.onStop();
    AppUtils.deleteCache(getApplicationContext());
}
public class AppUtils {
    public static void deleteCache(Context context) {
        try {
            File dir = context.getCacheDir();
            deleteDir(dir);
        } catch (Exception e) {}
    }

    public static boolean deleteDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
            return dir.delete();
        } else if(dir!= null && dir.isFile()) {
            return dir.delete();
        } else {
            return false;
        }
    }
}

Capture key press without placing an input element on the page?

jQuery also has an excellent implementation that's incredibly easy to use. Here's how you could implement this functionality across browsers:

$(document).keypress(function(e){
    var checkWebkitandIE=(e.which==26 ? 1 : 0);
    var checkMoz=(e.which==122 && e.ctrlKey ? 1 : 0);

    if (checkWebkitandIE || checkMoz) $("body").append("<p>ctrl+z detected!</p>");
});

Tested in IE7,Firefox 3.6.3 & Chrome 4.1.249.1064

Another way of doing this is to use the keydown event and track the event.keyCode. However, since jQuery normalizes keyCode and charCode using event.which, their spec recommends using event.which in a variety of situations:

$(document).keydown(function(e){
if (e.keyCode==90 && e.ctrlKey)
    $("body").append("<p>ctrl+z detected!</p>");
});

Is there a way to iterate over a dictionary?

The block approach avoids running the lookup algorithm for every key:

[dict enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL* stop) {
  NSLog(@"%@ => %@", key, value);
}];

Even though NSDictionary is implemented as a hashtable (which means that the cost of looking up an element is O(1)), lookups still slow down your iteration by a constant factor.

My measurements show that for a dictionary d of numbers ...

NSMutableDictionary* dict = [NSMutableDictionary dictionary];
for (int i = 0; i < 5000000; ++i) {
  NSNumber* value = @(i);
  dict[value.stringValue] = value;
}

... summing up the numbers with the block approach ...

__block int sum = 0;
[dict enumerateKeysAndObjectsUsingBlock:^(NSString* key, NSNumber* value, BOOL* stop) {
  sum += value.intValue;
}];

... rather than the loop approach ...

int sum = 0;
for (NSString* key in dict)
  sum += [dict[key] intValue];

... is about 40% faster.

EDIT: The new SDK (6.1+) appears to optimise loop iteration, so the loop approach is now about 20% faster than the block approach, at least for the simple case above.

MySQL delete multiple rows in one query conditions unique to each row

You were very close, you can use this:

DELETE FROM table WHERE (col1,col2) IN ((1,2),(3,4),(5,6))

Please see this fiddle.

What is a provisioning profile used for when developing iPhone applications?

A Quote from : iPhone Developer Program (~8MB PDF)

A provisioning profile is a collection of digital entities that uniquely ties developers and devices to an authorized iPhone Development Team and enables a device to be used for testing. A Development Provisioning Profile must be installed on each device on which you wish to run your application code. Each Development Provisioning Profile will contain a set of iPhone Development Certificates, Unique Device Identifiers and an App ID. Devices specified within the provisioning profile can be used for testing only by those individuals whose iPhone Development Certificates are included in the profile. A single device can contain multiple provisioning profiles.

REST API Login Pattern

Principled Design of the Modern Web Architecture by Roy T. Fielding and Richard N. Taylor, i.e. sequence of works from all REST terminology came from, contains definition of client-server interaction:

All REST interactions are stateless. That is, each request contains all of the information necessary for a connector to understand the request, independent of any requests that may have preceded it.

This restriction accomplishes four functions, 1st and 3rd are important in this particular case:

  • 1st: it removes any need for the connectors to retain application state between requests, thus reducing consumption of physical resources and improving scalability;
  • 3rd: it allows an intermediary to view and understand a request in isolation, which may be necessary when services are dynamically rearranged;

And now lets go back to your security case. Every single request should contains all required information, and authorization/authentication is not an exception. How to achieve this? Literally send all required information over wires with every request.

One of examples how to archeive this is hash-based message authentication code or HMAC. In practice this means adding a hash code of current message to every request. Hash code calculated by cryptographic hash function in combination with a secret cryptographic key. Cryptographic hash function is either predefined or part of code-on-demand REST conception (for example JavaScript). Secret cryptographic key should be provided by server to client as resource, and client uses it to calculate hash code for every request.

There are a lot of examples of HMAC implementations, but I'd like you to pay attention to the following three:

How it works in practice

If client knows the secret key, then it's ready to operate with resources. Otherwise he will be temporarily redirected (status code 307 Temporary Redirect) to authorize and to get secret key, and then redirected back to the original resource. In this case there is no need to know beforehand (i.e. hardcode somewhere) what the URL to authorize the client is, and it possible to adjust this schema with time.

Hope this will helps you to find the proper solution!

How Can I Remove “public/index.php” in the URL Generated Laravel?

Don't get confused with other option the snippet below I am using and will be useful for you too. Put the below htacces in your root.

<IfModule mod_rewrite.c>
    RewriteEngine on
    RewriteRule    ^$    public/    [L]
    RewriteRule    (.*) public/$1    [L]
</IfModule>

Go to your public directory and put another htaccess file with the code snippet below

<IfModule mod_rewrite.c>
    RewriteEngine On
    # Removes index.php from ExpressionEngine URLs  
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)$ index.php?url=$1 [PT,L]

</IfModule>

Its working... !!!

Laravel Uses below .htaccess

    # Redirect Trailing Slashes If Not A Folder...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_URI} (.+)/$
    RewriteRule ^ %1 [L,R=301]

    # Handle Front Controller...
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.php [L]

How can get the text of a div tag using only javascript (no jQuery)

You can use innerHTML(then parse text from HTML) or use innerText.

let textContentWithHTMLTags = document.querySelector('div').innerHTML; 
let textContent = document.querySelector('div').innerText;

console.log(textContentWithHTMLTags, textContent);

innerHTML and innerText is supported by all browser(except FireFox < 44) including IE6.

jQuery selector to get form by name

You have no combinator (space, >, +...) so no children will get involved, ever.

However, you could avoid the need for jQuery by using an ID and getElementById, or you could use the old getElementsByName("frmSave")[0] or the even older document.forms['frmSave']. jQuery is unnecessary here.

How to make an image center (vertically & horizontally) inside a bigger div

Here try this out.

_x000D_
_x000D_
.parentdiv {_x000D_
 height: 400px;_x000D_
 border: 2px solid #cccccc;_x000D_
  background: #efefef;_x000D_
 position: relative;_x000D_
}_x000D_
.childcontainer {_x000D_
 position: absolute;_x000D_
 left: 50%;_x000D_
 top: 50%;_x000D_
}_x000D_
.childdiv {_x000D_
 width: 150px;_x000D_
 height:150px;_x000D_
 background: lightgreen;_x000D_
 border-radius: 50%;_x000D_
 border: 2px solid green;_x000D_
 margin-top: -50%;_x000D_
 margin-left: -50%;_x000D_
}
_x000D_
<div class="parentdiv">_x000D_
  <div class="childcontainer">_x000D_
     <div class="childdiv">_x000D_
     </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How can I rename column in laravel using migration?

Throwing my $0.02 in here since none of the answers worked, but did send me on the right path. What happened was that a previous foreign constraint was throwing the error. Obvious when you think about it.

So in your new migration's up method, first drop that original constraint, rename the column, then add the constraint again with the new column name. In the down method, you do the exact opposite so that it's back to the sold setting.

/**
 * Run the migrations.
 *
 * @return void
 */
public function up()
{
    Schema::table('proxy4s', function (Blueprint $table) {
        // Drop it
        $table->dropForeign(['server_id']);

        // Rename
        $table->renameColumn('server_id', 'linux_server_id');

        // Add it
        $table->foreign('linux_server_id')->references('id')->on('linux_servers');
    });
}

/**
 * Reverse the migrations.
 *
 * @return void
 */
public function down()
{
    Schema::table('proxy4s', function (Blueprint $table) {
        // Drop it
        $table->dropForeign(['linux_server_id']);

        // Rename
        $table->renameColumn('linux_server_id', 'server_id');

        // Add it
        $table->foreign('server_id')->references('id')->on('linux_servers');
    });
}

Hope this saves someone some time in the future!

Difference between numpy.array shape (R, 1) and (R,)

1. The meaning of shapes in NumPy

You write, "I know literally it's list of numbers and list of lists where all list contains only a number" but that's a bit of an unhelpful way to think about it.

The best way to think about NumPy arrays is that they consist of two parts, a data buffer which is just a block of raw elements, and a view which describes how to interpret the data buffer.

For example, if we create an array of 12 integers:

>>> a = numpy.arange(12)
>>> a
array([ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11])

Then a consists of a data buffer, arranged something like this:

+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

and a view which describes how to interpret the data:

>>> a.flags
  C_CONTIGUOUS : True
  F_CONTIGUOUS : True
  OWNDATA : True
  WRITEABLE : True
  ALIGNED : True
  UPDATEIFCOPY : False
>>> a.dtype
dtype('int64')
>>> a.itemsize
8
>>> a.strides
(8,)
>>> a.shape
(12,)

Here the shape (12,) means the array is indexed by a single index which runs from 0 to 11. Conceptually, if we label this single index i, the array a looks like this:

i= 0    1    2    3    4    5    6    7    8    9   10   11
+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

If we reshape an array, this doesn't change the data buffer. Instead, it creates a new view that describes a different way to interpret the data. So after:

>>> b = a.reshape((3, 4))

the array b has the same data buffer as a, but now it is indexed by two indices which run from 0 to 2 and 0 to 3 respectively. If we label the two indices i and j, the array b looks like this:

i= 0    0    0    0    1    1    1    1    2    2    2    2
j= 0    1    2    3    0    1    2    3    0    1    2    3
+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

which means that:

>>> b[2,1]
9

You can see that the second index changes quickly and the first index changes slowly. If you prefer this to be the other way round, you can specify the order parameter:

>>> c = a.reshape((3, 4), order='F')

which results in an array indexed like this:

i= 0    1    2    0    1    2    0    1    2    0    1    2
j= 0    0    0    1    1    1    2    2    2    3    3    3
+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

which means that:

>>> c[2,1]
5

It should now be clear what it means for an array to have a shape with one or more dimensions of size 1. After:

>>> d = a.reshape((12, 1))

the array d is indexed by two indices, the first of which runs from 0 to 11, and the second index is always 0:

i= 0    1    2    3    4    5    6    7    8    9   10   11
j= 0    0    0    0    0    0    0    0    0    0    0    0
+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

and so:

>>> d[10,0]
10

A dimension of length 1 is "free" (in some sense), so there's nothing stopping you from going to town:

>>> e = a.reshape((1, 2, 1, 6, 1))

giving an array indexed like this:

i= 0    0    0    0    0    0    0    0    0    0    0    0
j= 0    0    0    0    0    0    1    1    1    1    1    1
k= 0    0    0    0    0    0    0    0    0    0    0    0
l= 0    1    2    3    4    5    0    1    2    3    4    5
m= 0    0    0    0    0    0    0    0    0    0    0    0
+-----------------------------------------------------------+
¦  0 ¦  1 ¦  2 ¦  3 ¦  4 ¦  5 ¦  6 ¦  7 ¦  8 ¦  9 ¦ 10 ¦ 11 ¦
+-----------------------------------------------------------+

and so:

>>> e[0,1,0,0,0]
6

See the NumPy internals documentation for more details about how arrays are implemented.

2. What to do?

Since numpy.reshape just creates a new view, you shouldn't be scared about using it whenever necessary. It's the right tool to use when you want to index an array in a different way.

However, in a long computation it's usually possible to arrange to construct arrays with the "right" shape in the first place, and so minimize the number of reshapes and transposes. But without seeing the actual context that led to the need for a reshape, it's hard to say what should be changed.

The example in your question is:

numpy.dot(M[:,0], numpy.ones((1, R)))

but this is not realistic. First, this expression:

M[:,0].sum()

computes the result more simply. Second, is there really something special about column 0? Perhaps what you actually need is:

M.sum(axis=0)

How to use _CRT_SECURE_NO_WARNINGS

I was getting the same error in Visual Studio 2017 and to fix it just added #define _CRT_SECURE_NO_WARNINGS after #include "pch.h"

#include "pch.h"
#define _CRT_SECURE_NO_WARNINGS
....

How do I add an active class to a Link from React Router?

As of [email protected], we can just easily use the NavLink with activeClassName instead of Link. Example:

import React, { Component } from 'react';
import { NavLink } from 'react-router-dom';

class NavBar extends Component {
  render() {
    return (
      <div className="navbar">
        <ul>
          <li><NavLink to='/1' activeClassName="active">1</NavLink></li>
          <li><NavLink to='/2' activeClassName="active">2</NavLink></li>
          <li><NavLink to='/3' activeClassName="active">3</NavLink></li>
        </ul>
      </div>
    );
  }
}

Then in your CSS file:

.navbar li>.active {
  font-weight: bold;
}

The NavLink will add your custom styling attributes to the rendered element based on the current URL.

Document is here

What is the difference between a Docker image and a container?

I couldn't understand the concept of image and layer in spite of reading all the questions here and then eventually stumbled upon this excellent documentation from Docker (duh!).

The example there is really the key to understand the whole concept. It is a lengthy post, so I am summarising the key points that need to be really grasped to get clarity.

  • Image: A Docker image is built up from a series of read-only layers

  • Layer: Each layer represents an instruction in the image’s Dockerfile.

Example: The below Dockerfile contains four commands, each of which creates a layer.

FROM ubuntu:15.04

COPY . /app

RUN make /app

CMD python /app/app.py

Importantly, each layer is only a set of differences from the layer before it.

  • Container. When you create a new container, you add a new writable layer on top of the underlying layers. This layer is often called the “container layer”. All changes made to the running container, such as writing new files, modifying existing files, and deleting files, are written to this thin writable container layer.

Hence, the major difference between a container and an image is the top writable layer. All writes to the container that add new or modify existing data are stored in this writable layer. When the container is deleted, the writable layer is also deleted. The underlying image remains unchanged.

Understanding images cnd Containers from a size-on-disk perspective

To view the approximate size of a running container, you can use the docker ps -s command. You get size and virtual size as two of the outputs:

  • Size: the amount of data (on disk) that is used for the writable layer of each container

  • Virtual Size: the amount of data used for the read-only image data used by the container. Multiple containers may share some or all read-only image data. Hence these are not additive. I.e. you can't add all the virtual sizes to calculate how much size on disk is used by the image

Another important concept is the copy-on-write strategy

If a file or directory exists in a lower layer within the image, and another layer (including the writable layer) needs read access to it, it just uses the existing file. The first time another layer needs to modify the file (when building the image or running the container), the file is copied into that layer and modified.

I hope that helps someone else like me.

Java executors: how to be notified, without blocking, when a task completes?

Simple code to implement Callback mechanism using ExecutorService

import java.util.concurrent.*;
import java.util.*;

public class CallBackDemo{
    public CallBackDemo(){
        System.out.println("creating service");
        ExecutorService service = Executors.newFixedThreadPool(5);

        try{
            for ( int i=0; i<5; i++){
                Callback callback = new Callback(i+1);
                MyCallable myCallable = new MyCallable((long)i+1,callback);
                Future<Long> future = service.submit(myCallable);
                //System.out.println("future status:"+future.get()+":"+future.isDone());
            }
        }catch(Exception err){
            err.printStackTrace();
        }
        service.shutdown();
    }
    public static void main(String args[]){
        CallBackDemo demo = new CallBackDemo();
    }
}
class MyCallable implements Callable<Long>{
    Long id = 0L;
    Callback callback;
    public MyCallable(Long val,Callback obj){
        this.id = val;
        this.callback = obj;
    }
    public Long call(){
        //Add your business logic
        System.out.println("Callable:"+id+":"+Thread.currentThread().getName());
        callback.callbackMethod();
        return id;
    }
}
class Callback {
    private int i;
    public Callback(int i){
        this.i = i;
    }
    public void callbackMethod(){
        System.out.println("Call back:"+i);
        // Add your business logic
    }
}

output:

creating service
Callable:1:pool-1-thread-1
Call back:1
Callable:3:pool-1-thread-3
Callable:2:pool-1-thread-2
Call back:2
Callable:5:pool-1-thread-5
Call back:5
Call back:3
Callable:4:pool-1-thread-4
Call back:4

Key notes:

  1. If you want process tasks in sequence in FIFO order, replace newFixedThreadPool(5) with newFixedThreadPool(1)
  2. If you want to process next task after analysing the result from callback of previous task,just un-comment below line

    //System.out.println("future status:"+future.get()+":"+future.isDone());
    
  3. You can replace newFixedThreadPool() with one of

    Executors.newCachedThreadPool()
    Executors.newWorkStealingPool()
    ThreadPoolExecutor
    

    depending on your use case.

  4. If you want to handle callback method asynchronously

    a. Pass a shared ExecutorService or ThreadPoolExecutor to Callable task

    b. Convert your Callable method to Callable/Runnable task

    c. Push callback task to ExecutorService or ThreadPoolExecutor

Iterate through pairs of items in a Python list

To do that you should do:

a =  [5, 7, 11, 4, 5]
for i in range(len(a)-1):
    print [a[i], a[i+1]]

How do I perform a JAVA callback between classes?

I don't know if this is what you are looking for, but you can achieve this by passing a callback to the child class.

first define a generic callback:

public interface ITypedCallback<T> {
    void execute(T type);
}

create a new ITypedCallback instance on ServerConnections instantiation:

public Server(int _address) {
    serverConnectionHandler = new ServerConnections(new ITypedCallback<Socket>() {
        @Override
        public void execute(Socket socket) {
            // do something with your socket here
        }
    });
}

call the execute methode on the callback object.

public class ServerConnections implements Runnable {

    private ITypedCallback<Socket> callback;

    public ServerConnections(ITypedCallback<Socket> _callback) {
        callback = _callback;
    }

    @Override
    public void run() {   
        try {
            mainSocket = new ServerSocket(serverPort);
            while (true) {
                callback.execute(mainSocket.accept());
            }
        } catch (IOException ex) {
            Logger.getLogger(Server.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}

btw: I didn't check if it's 100% correct, directly coded it here.

Matplotlib subplots_adjust hspace so titles and xlabels don't overlap?

The link posted by Jose has been updated and pylab now has a tight_layout() function that does this automatically (in matplotlib version 1.1.0).

http://matplotlib.org/api/pyplot_api.html#matplotlib.pyplot.tight_layout

http://matplotlib.org/users/tight_layout_guide.html#plotting-guide-tight-layout

How to get the current time in YYYY-MM-DD HH:MI:Sec.Millisecond format in Java?

You can simply get it in the format you want.

String date = String.valueOf(android.text.format.DateFormat.format("dd-MM-yyyy", new java.util.Date()));

Initializing a list to a known number of elements in Python

One obvious and probably not efficient way is

verts = [0 for x in range(1000)]

Note that this can be extended to 2-dimension easily. For example, to get a 10x100 "array" you can do

verts = [[0 for x in range(100)] for y in range(10)]

Jar mismatch! Fix your dependencies

  1. Jar mismatch comes when you use library projects in your application and both projects are using same jar with different version so just check all library projects attached in your application. if some mismatch exist then remove it.

  2. if above process is not working then just do remove project dependency from build path and again add library projects and build the application.

What is the best IDE to develop Android apps in?

I've been using IntelliJ IDEA for the last 12 months now as my main IDE, but I am often forced to use Eclipse as well. So when I have to work in Eclipse I start biting my nails. I will sum up my pros and cons.

Eclipse pros:
- visual editor. IDEA has one as well, but it's rather primitive. I suspect that this feature will soon be deleted as IDEA will improve its editor.
- many projects into one right pane (this is also my personal con as I like IDEA's one-project-per-pane thing)
- faster compiles Android projects. IDEA has made its compilation process faster, so I also soon expect to delete this Eclipse pro

IDEA pros:
- faster intellisense (if you like Resharper, then you know what I am talking about)
- smarter autocomplete - my friend and I decided to write the same class. I finished before him simply because IDEA faster reacts to my wishes
- incredibly smart - do not know what to do? just press Ctrl+Shift+Space and IDEA will tell you what should come there. It also recognizes naming scheme to if you're filling name object, it will first display getName method.
- will add more as I remember of them

IDEA cons:
- Still the only con is that if you open Eclipse Android project and edit any XML layout file, Eclipse will no longer be able to display edited file into its visual layout editor. This has not been fixed as of this day and it's IDEA's bug as it somehow messes the XML.

Bottom line: if you're a person who does not see advantages of ReSharper in .NET (and we all coded in .NET), then you'll probably stick to Eclipse. It's official Android IDE and you believe it's the best.
If you liked ReSharper and want to code faster, then you'll appreciate IDEA and will stick to it forever.

How to access List elements

I'd start by not calling it list, since that's the name of the constructor for Python's built in list type.

But once you've renamed it to cities or something, you'd do:

print(cities[0][0], cities[1][0])
print(cities[0][1], cities[1][1])

When should we use mutex and when should we use semaphore

Mutex is to protect the shared resource.
Semaphore is to dispatch the threads.

Mutex:
Imagine that there are some tickets to sell. We can simulate a case where many people buy the tickets at the same time: each person is a thread to buy tickets. Obviously we need to use the mutex to protect the tickets because it is the shared resource.


Semaphore:
Imagine that we need to do a calculation as below:

c = a + b;

Also, we need a function geta() to calculate a, a function getb() to calculate b and a function getc() to do the calculation c = a + b.

Obviously, we can't do the c = a + b unless geta() and getb() have been finished.
If the three functions are three threads, we need to dispatch the three threads.

int a, b, c;
void geta()
{
    a = calculatea();
    semaphore_increase();
}

void getb()
{
    b = calculateb();
    semaphore_increase();
}

void getc()
{
    semaphore_decrease();
    semaphore_decrease();
    c = a + b;
}

t1 = thread_create(geta);
t2 = thread_create(getb);
t3 = thread_create(getc);
thread_join(t3);

With the help of the semaphore, the code above can make sure that t3 won't do its job untill t1 and t2 have done their jobs.

In a word, semaphore is to make threads execute as a logicial order whereas mutex is to protect shared resource.
So they are NOT the same thing even if some people always say that mutex is a special semaphore with the initial value 1. You can say like this too but please notice that they are used in different cases. Don't replace one by the other even if you can do that.

How to get time (hour, minute, second) in Swift 3 using NSDate?

Swift 4.2 & 5

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = Calendar.current

// *** Get components using current Local & Timezone ***
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date))

// *** define calendar components to use as well Timezone to UTC ***
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents([.hour, .year, .minute], from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Swift 3.0

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = NSCalendar.current

// *** Get components using current Local & Timezone ***    
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date as Date))

// *** define calendar components to use as well Timezone to UTC ***
let unitFlags = Set<Calendar.Component>([.hour, .year, .minute])
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents(unitFlags, from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

How to use SSH to run a local shell script on a remote machine?

First, copy the script over to Machine B using scp

[user@machineA]$ scp /path/to/script user@machineB:/home/user/path

Then, just run the script

[user@machineA]$ ssh user@machineB "/home/user/path/script"

This will work if you have given executable permission to the script.

How do I access my SSH public key?

If you are using Windows PowerShell, the easiest way is to:

cat ~/.ssh/id_<key-type-here>.pub | clip

That will copy the key to your clipboard for easy pasting.

So, in my instance, I use ed25519 since RSA is now fairly hackable:

cat ~/.ssh/id_ed25519.pub | clip

Because I find myself doing this a lot, I created a function and set a simple alias I could remember in my PowerShell profile (learn more about PowerShell profiles here. Just add this to your Microsoft.PowerShell_profile.ps1:

function Copy-SSHKey {
    Get-Content ~/.ssh/id_ed25519.pub | clip
}

Set_Alias -Name sshkey -Value Copy-SSHKey

Then, in a PowerShell console, run . $profile to load the functions. Then from now on all you will need to do is run sshkey, and then paste the key into wherever you need via the clipboard.

Google Apps Script to open a URL

You can build a small UI that does the job like this :

function test(){
showURL("http://www.google.com")
}
//
function showURL(href){
  var app = UiApp.createApplication().setHeight(50).setWidth(200);
  app.setTitle("Show URL");
  var link = app.createAnchor('open ', href).setId("link");
  app.add(link);  
  var doc = SpreadsheetApp.getActive();
  doc.show(app);
  }

If you want to 'show' the URL, just change this line like this :

  var link = app.createAnchor(href, href).setId("link");

EDIT : link to a demo spreadsheet in read only because too many people keep writing unwanted things on it (just make a copy to use instead).

EDIT : UiApp was deprecated by Google on 11th Dec 2014, this method could break at any time and needs updating to use HTML service instead!

EDIT : below is an implementation using html service.

function testNew(){
  showAnchor('Stackoverflow','http://stackoverflow.com/questions/tagged/google-apps-script');
}

function showAnchor(name,url) {
  var html = '<html><body><a href="'+url+'" target="blank" onclick="google.script.host.close()">'+name+'</a></body></html>';
  var ui = HtmlService.createHtmlOutput(html)
  SpreadsheetApp.getUi().showModelessDialog(ui,"demo");
}

How do I select the "last child" with a specific class name in CSS?

You can use the adjacent sibling selector to achieve something similar, that might help.

.list-item.other-class + .list-item:not(.other-class)

Will effectively target the immediately following element after the last element with the class other-class.

Read more here: https://css-tricks.com/almanac/selectors/a/adjacent-sibling/

How to use a variable for a key in a JavaScript object literal?

Given code:

var thetop = 'top';
<something>.stop().animate(
    { thetop : 10 }, 10
);

Translation:

var thetop = 'top';
var config = { thetop : 10 }; // config.thetop = 10
<something>.stop().animate(config, 10);

As you can see, the { thetop : 10 } declaration doesn't make use of the variable thetop. Instead it creates an object with a key named thetop. If you want the key to be the value of the variable thetop, then you will have to use square brackets around thetop:

var thetop = 'top';
var config = { [thetop] : 10 }; // config.top = 10
<something>.stop().animate(config, 10);

The square bracket syntax has been introduced with ES6. In earlier versions of JavaScript, you would have to do the following:

var thetop = 'top';
var config = (
  obj = {},
  obj['' + thetop] = 10,
  obj
); // config.top = 10
<something>.stop().animate(config, 10);

Empty an array in Java / processing

If Array xco is not final then a simple reassignment would work:

i.e.

xco = new Float[xco .length];

This assumes you need the Array xco to remain the same size. If that's not necessary then create an empty array:

xco= new Float[0];

Delete the 'first' record from a table in SQL Server, without a WHERE condition

depends on your DBMS (people don't seem to know what that is nowadays)

-- MYSql:
DELETE FROM table LIMIT 1;
-- Postgres:
DELETE FROM table LIMIT 1;
-- MSSql:
DELETE TOP(1) FROM table;
-- Oracle:
DELETE FROM table WHERE ROWNUM = 1;

Overlaying histograms with ggplot2 in R

Using @joran's sample data,

ggplot(dat, aes(x=xx, fill=yy)) + geom_histogram(alpha=0.2, position="identity")

note that the default position of geom_histogram is "stack."

see "position adjustment" of this page:

docs.ggplot2.org/current/geom_histogram.html

How can I get the MAC and the IP address of a connected client in PHP?

All you need to do is to put arp into diferrent group.

Default:

-rwxr-xr-x 1 root root 48K 2008-11-11 18:11 /usr/sbin/arp*

With command:

sudo chown root:www-data /usr/sbin/arp

you will get:

-rwxr-xr-x 1 root www-data 48K 2008-11-11 18:11 /usr/sbin/arp*

And because apache is a daemon running under the user www-data, it's now able to execute this command.

So if you now use a PHP script, e.g.:

<?php
$mac = system('arp -an');
echo $mac;
?>

you will get the output of linux arp -an command.

Programmatically Hide/Show Android Soft Keyboard

Adding this to your code android:focusableInTouchMode="true" will make sure that your keypad doesn't appear on startup for your edittext box. You want to add this line to your linear layout that contains the EditTextBox. You should be able to play with this to solve both your problems. I have tested this. Simple solution.

ie: In your app_list_view.xml file

<LinearLayout 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" 
    android:focusableInTouchMode="true">
    <EditText 
        android:id="@+id/filter_edittext"       
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:hint="Search" 
        android:inputType="text" 
        android:maxLines="1"/>
    <ListView 
        android:id="@id/android:list" 
        android:layout_height="fill_parent"
        android:layout_weight="1.0" 
        android:layout_width="fill_parent" 
        android:focusable="true" 
        android:descendantFocusability="beforeDescendants"/>
</LinearLayout> 

------------------ EDIT: To Make keyboard appear on startup -----------------------

This is to make they Keyboard appear on the username edittextbox on startup. All I've done is added an empty Scrollview to the bottom of the .xml file, this puts the first edittext into focus and pops up the keyboard. I admit this is a hack, but I am assuming you just want this to work. I've tested it, and it works fine.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:orientation="vertical" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:paddingLeft="20dip"  
    android:paddingRight="20dip">
    <EditText 
        android:id="@+id/userName" 
        android:singleLine="true" 
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content" 
        android:hint="Username"  
        android:imeOptions="actionDone" 
        android:inputType="text"
        android:maxLines="1"
       />
    <EditText 
        android:id="@+id/password" 
        android:password="true" 
        android:singleLine="true"  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:hint="Password" />
    <ScrollView
        android:id="@+id/ScrollView01"  
        android:layout_height="fill_parent"   
        android:layout_width="fill_parent"> 
    </ScrollView>
</LinearLayout>

If you are looking for a more eloquent solution, I've found this question which might help you out, it is not as simple as the solution above but probably a better solution. I haven't tested it but it apparently works. I think it is similar to the solution you've tried which didn't work for you though.

Hope this is what you are looking for.

Cheers!

How do you sort an array on multiple columns?

Came across a need to do SQL-style mixed asc and desc object array sorts by keys.

kennebec's solution above helped me get to this:

Array.prototype.keySort = function(keys) {

keys = keys || {};

// via
// https://stackoverflow.com/questions/5223/length-of-javascript-object-ie-associative-array
var obLen = function(obj) {
    var size = 0, key;
    for (key in obj) {
        if (obj.hasOwnProperty(key))
            size++;
    }
    return size;
};

// avoiding using Object.keys because I guess did it have IE8 issues?
// else var obIx = function(obj, ix){ return Object.keys(obj)[ix]; } or
// whatever
var obIx = function(obj, ix) {
    var size = 0, key;
    for (key in obj) {
        if (obj.hasOwnProperty(key)) {
            if (size == ix)
                return key;
            size++;
        }
    }
    return false;
};

var keySort = function(a, b, d) {
    d = d !== null ? d : 1;
    // a = a.toLowerCase(); // this breaks numbers
    // b = b.toLowerCase();
    if (a == b)
        return 0;
    return a > b ? 1 * d : -1 * d;
};

var KL = obLen(keys);

if (!KL)
    return this.sort(keySort);

for ( var k in keys) {
    // asc unless desc or skip
    keys[k] = 
            keys[k] == 'desc' || keys[k] == -1  ? -1 
          : (keys[k] == 'skip' || keys[k] === 0 ? 0 
          : 1);
}

this.sort(function(a, b) {
    var sorted = 0, ix = 0;

    while (sorted === 0 && ix < KL) {
        var k = obIx(keys, ix);
        if (k) {
            var dir = keys[k];
            sorted = keySort(a[k], b[k], dir);
            ix++;
        }
    }
    return sorted;
});
return this;
};

sample usage:

var obja = [
  {USER:"bob",  SCORE:2000, TIME:32,    AGE:16, COUNTRY:"US"},
  {USER:"jane", SCORE:4000, TIME:35,    AGE:16, COUNTRY:"DE"},
  {USER:"tim",  SCORE:1000, TIME:30,    AGE:17, COUNTRY:"UK"},
  {USER:"mary", SCORE:1500, TIME:31,    AGE:19, COUNTRY:"PL"},
  {USER:"joe",  SCORE:2500, TIME:33,    AGE:18, COUNTRY:"US"},
  {USER:"sally",    SCORE:2000, TIME:30,    AGE:16, COUNTRY:"CA"},
  {USER:"yuri", SCORE:3000, TIME:34,    AGE:19, COUNTRY:"RU"},
  {USER:"anita",    SCORE:2500, TIME:32,    AGE:17, COUNTRY:"LV"},
  {USER:"mark", SCORE:2000, TIME:30,    AGE:18, COUNTRY:"DE"},
  {USER:"amy",  SCORE:1500, TIME:29,    AGE:19, COUNTRY:"UK"}
];

var sorto = {
  SCORE:"desc",TIME:"asc", AGE:"asc"
};

obja.keySort(sorto);

yields the following:

 0: {     USER: jane;     SCORE: 4000;    TIME: 35;       AGE: 16;    COUNTRY: DE;   }
 1: {     USER: yuri;     SCORE: 3000;    TIME: 34;       AGE: 19;    COUNTRY: RU;   }
 2: {     USER: anita;    SCORE: 2500;    TIME: 32;       AGE: 17;    COUNTRY: LV;   }
 3: {     USER: joe;      SCORE: 2500;    TIME: 33;       AGE: 18;    COUNTRY: US;   }
 4: {     USER: sally;    SCORE: 2000;    TIME: 30;       AGE: 16;    COUNTRY: CA;   }
 5: {     USER: mark;     SCORE: 2000;    TIME: 30;       AGE: 18;    COUNTRY: DE;   }
 6: {     USER: bob;      SCORE: 2000;    TIME: 32;       AGE: 16;    COUNTRY: US;   }
 7: {     USER: amy;      SCORE: 1500;    TIME: 29;       AGE: 19;    COUNTRY: UK;   }
 8: {     USER: mary;     SCORE: 1500;    TIME: 31;       AGE: 19;    COUNTRY: PL;   }
 9: {     USER: tim;      SCORE: 1000;    TIME: 30;       AGE: 17;    COUNTRY: UK;   }
 keySort: {  }

(using a print function from here)

here is a jsbin example.

edit: cleaned up and posted as mksort.js on github.

Rails DB Migration - How To Drop a Table?

if you want to drop a specific table you can do

$ rails db:migrate:up VERSION=[Here you can insert timestamp of table]

otherwise if you want to drop all your database you can do

$rails db:drop

How to compare times in Python?

Surprised I haven't seen this one liner here:

datetime.datetime.now().hour == 8

Resizing UITableView to fit content

Swift 3, iOS 10.3

Solution 1: Just put self.tableview.sizeToFit() in cellForRowAt indexPath function. Make sure to set tableview height higher then you need. This is a good solution if you don't have views below tableview. However, if you have, bottom tableview constraint will not be updated (I didn't try to fix it because I came up with solution 2)

Example:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCell(withIdentifier: "TestCell", for: indexPath) as? TestCell {
        cell.configureCell(data: testArray[indexPath.row])
        self.postsTableView.sizeToFit()
        return cell
    }

    return UITableViewCell()
}

Solution 2: Set tableview height constraint in storyboard and drag it to the ViewController. If you know the average height of your cell and you know how many elements your array contains, you can do something like this:

tableViewHeightConstraint.constant = CGFloat(testArray.count) * 90.0     // Let's say 90 is the average cell height

*EDIT:

After all the solutions I tried and every of them was fixing something, but not completely, this is the answer that explains and fixes this problem completely.

Handle Guzzle exception and get HTTP body

While the answers above are good they will not catch network errors. As Mark mentioned, BadResponseException is just a super class for ClientException and ServerException. But RequestException is also a super class of BadResponseException. RequestException will be thrown for not only 400 and 500 errors but network errors and infinite redirects too. So let's say you request the page below but your network is playing up and your catch is only expecting a BadResponseException. Well your application will throw an error.

It's better in this case to expect RequestException and check for a response.

try {
  $client->get('http://123123123.com')
} catch (RequestException $e) {

  // If there are network errors, we need to ensure the application doesn't crash.
  // if $e->hasResponse is not null we can attempt to get the message
  // Otherwise, we'll just pass a network unavailable message.
  if ($e->hasResponse()) {
    $exception = (string) $e->getResponse()->getBody();
    $exception = json_decode($exception);
    return new JsonResponse($exception, $e->getCode());
  } else {
    return new JsonResponse($e->getMessage(), 503);
  }

}

Passing data to components in vue.js

The above-mentioned responses work well but if you want to pass data between 2 sibling components, then the event bus can also be used. Check out this blog which would help you understand better.

supppose for 2 components : CompA & CompB having same parent and main.js for setting up main vue app. For passing data from CompA to CompB without involving parent component you can do the following.

in main.js file, declare a separate global Vue instance, that will be event bus.

export const bus = new Vue();

In CompA, where the event is generated : you have to emit the event to bus.

methods: {
      somethingHappened (){
          bus.$emit('changedSomething', 'new data');
      }
  }

Now the task is to listen the emitted event, so, in CompB, you can listen like.

created (){
    bus.$on('changedSomething', (newData) => {
      console.log(newData);
    })
  }

Advantages:

  • Less & Clean code.
  • Parent should not involve in passing down data from 1 child comp to another ( as the number of children grows, it will become hard to maintain )
  • Follows pub-sub approach.

Add a CSS class to <%= f.submit %>

both of them works <%= f.submit class: "btn btn-primary" %> and <%= f.submit "Name of Button", class: "btn btn-primary "%>

Redirect to specified URL on PHP script completion?

Note that this will not work:

header('Location: $url');

You need to do this (for variable expansion):

header("Location: $url");

How to visualize an XML schema?

There is a new free-to-use webtool, where you can view any xml schema:

Online XML Schema Viewer

www.xml-tools.net

It's written completely in JavaScript, so it's running in most modern browsers.

convert string into array of integers

us the split function:

var splitresult = "14 2".split(" ");

Is it possible to hide the cursor in a webpage using CSS or Javascript?

Pointer Lock API

While the cursor: none CSS solution is definitely a solid and easy workaround, if your actual goal is to remove the default cursor while your web application is being used, or implement your own interpretation of raw mouse movement (for FPS games, for example), you might want to consider using the Pointer Lock API instead.

You can use requestPointerLock on an element to remove the cursor, and redirect all mousemove events to that element (which you may or may not handle):

document.body.requestPointerLock();

To release the lock, you can use exitPointerLock:

document.exitPointerLock();

Additional notes

No cursor, for real

This is a very powerful API call. It not only renders your cursor invisible, but it actually removes your operating system's native cursor. You won't be able to select text, or do anything with your mouse (except listening to some mouse events in your code) until the pointer lock is released (either by using exitPointerLock or pressing ESC in some browsers).

That is, you cannot leave the window with your cursor for it to show again, as there is no cursor.

Restrictions

As mentioned above, this is a very powerful API call, and is thus only allowed to be made in response to some direct user-interaction on the web, such as a click; for example:

document.addEventListener("click", function () {
    document.body.requestPointerLock();
});

Also, requestPointerLock won't work from a sandboxed iframe unless the allow-pointer-lock permission is set.

User-notifications

Some browsers will prompt the user for a confirmation before the lock is engaged, some will simply display a message. This means pointer lock might not activate right away after the call. However, the actual activation of pointer locking can be listened to by listening to the pointerchange event on the element on which requestPointerLock was called:

document.body.addEventListener("pointerlockchange", function () {
    if (document.pointerLockElement === document.body) {
        // Pointer is now locked to <body>.
    }
});

Most browsers will only display the message once, but Firefox will occasionally spam the message on every single call. AFAIK, this can only be worked around by user-settings, see Disable pointer-lock notification in Firefox.

Listening to raw mouse movement

The Pointer Lock API not only removes the mouse, but instead redirects raw mouse movement data to the element requestPointerLock was called on. This can be listened to simply by using the mousemove event, then accessing the movementX and movementY properties on the event object:

document.body.addEventListener("mousemove", function (e) {
    console.log("Moved by " + e.movementX + ", " + e.movementY);
});

C# Help reading foreign characters using StreamReader

For swedish Å Ä Ö the only solution form the ones above working was:

Encoding.GetEncoding("iso-8859-1")

Hopefully this will save someone time.

Convert a matrix to a 1 dimensional array

you can use as.vector(). It looks like it is the fastest method according to my little benchmark, as follows:

library(microbenchmark)
x=matrix(runif(1e4),100,100) # generate a 100x100 matrix
microbenchmark(y<-as.vector(x),y<-x[1:length(x)],y<-array(x),y<-c(x),times=1e4)

The first solution uses as.vector(), the second uses the fact that a matrix is stored as a contiguous array in memory and length(m) gives the number of elements in a matrix m. The third instantiates an array from x, and the fourth uses the concatenate function c(). I also tried unmatrix from gdata, but it's too slow to be mentioned here.

Here are some of the numerical results I obtained:

> microbenchmark(
        y<-as.vector(x),
        y<-x[1:length(x)],
        y<-array(x),
        y<-c(x),
        times=1e4)

Unit: microseconds
                expr    min      lq     mean  median      uq       max neval
   y <- as.vector(x)  8.251 13.1640 29.02656 14.4865 15.7900 69933.707 10000
 y <- x[1:length(x)] 59.709 70.8865 97.45981 73.5775 77.0910 75042.933 10000
       y <- array(x)  9.940 15.8895 26.24500 17.2330 18.4705  2106.090 10000
           y <- c(x) 22.406 33.8815 47.74805 40.7300 45.5955  1622.115 10000

Flattening a matrix is a common operation in Machine Learning, where a matrix can represent the parameters to learn but one uses an optimization algorithm from a generic library which expects a vector of parameters. So it is common to transform the matrix (or matrices) into such a vector. It's the case with the standard R function optim().

Adding default parameter value with type hint in Python

I recently saw this one-liner:

def foo(name: str, opts: dict=None) -> str:
    opts = {} if not opts else opts
    pass

ssh : Permission denied (publickey,gssapi-with-mic)

Nobody has mention this in. above answers so i am mentioning it.

This error can also come if you're in the wrong folder or path of your pem file is not correct. I was having similar issue and found that my pem file was not there from where i am executing the ssh command

cd KeyPair
ssh -i Keypair.pem [email protected]

Where to find Application Loader app in Mac?

You can also upload an app using the Application Loader tool by using it from the terminal:

MacBook-Pro:~ denis$ altool --upload-app -f "ios-app.ipa" -u "[email protected]" -p "yourpassword"

To use altool from anywhere in the terminal you could add it to your PATH env variable by typing in terminal:

MacBook-Pro:~ denis$ export PATH=$PATH:/Applications/Xcode.app/Contents/Applications/Application\ Loader.app/Contents/Frameworks/ITunesSoftwareService.framework/Support/
MacBook-Pro:~ denis$ source ~/.bash_profile

How to increase Bootstrap Modal Width?

If you want to keep the modal responsive use % of width instead of pixels. You can do it in-line (see below) or with CSS.

<div class="modal fade" id="phpModal" role="dialog">
            <div class="modal-dialog modal-lg" style="width:80%;">
                <div class="modal-content">
                    <div class="modal-header">
                        <button type="button" class="close" data-dismiss="modal">&times;</button>
                        <h4 class="modal-title">HERE YOU TITLE</h4>
                    </div>
                    <div class="modal-body helpModal phpModal">
                        HERE YOUR CONTENT
                    </div>
                </div>
            </div>
        </div>

If you use CSS, you can even do different % for modal-sm and modal-lg.

Check if string ends with certain pattern

This is really simple, the String object has an endsWith method.

From your question it seems like you want either /, , or . as the delimiter set.

So:

String str = "This.is.a.great.place.to.work.";

if (str.endsWith(".work.") || str.endsWith("/work/") || str.endsWith(",work,"))
     // ... 

You can also do this with the matches method and a fairly simple regex:

if (str.matches(".*([.,/])work\\1$"))

Using the character class [.,/] specifying either a period, a slash, or a comma, and a backreference, \1 that matches whichever of the alternates were found, if any.

How should a model be structured in MVC?

More oftenly most of the applications will have data,display and processing part and we just put all those in the letters M,V and C.

Model(M)-->Has the attributes that holds state of application and it dont know any thing about V and C.

View(V)-->Has displaying format for the application and and only knows about how-to-digest model on it and does not bother about C.

Controller(C)---->Has processing part of application and acts as wiring between M and V and it depends on both M,V unlike M and V.

Altogether there is separation of concern between each. In future any change or enhancements can be added very easily.

Disable JavaScript error in WebBrowser control

This disables the script errors and also disables other windows.. such as the NTLM login window or the client certificate accept window. The below will suppress only javascript errors.

// Hides script errors without hiding other dialog boxes.
private void SuppressScriptErrorsOnly(WebBrowser browser)
{
    // Ensure that ScriptErrorsSuppressed is set to false.
    browser.ScriptErrorsSuppressed = false;

    // Handle DocumentCompleted to gain access to the Document object.
    browser.DocumentCompleted +=
        new WebBrowserDocumentCompletedEventHandler(
            browser_DocumentCompleted);
}

private void browser_DocumentCompleted(object sender, 
    WebBrowserDocumentCompletedEventArgs e)
{
    ((WebBrowser)sender).Document.Window.Error += 
        new HtmlElementErrorEventHandler(Window_Error);
}

private void Window_Error(object sender, 
    HtmlElementErrorEventArgs e)
{
    // Ignore the error and suppress the error dialog box. 
    e.Handled = true;
}

What is the meaning of "int(a[::-1])" in Python?

The notation that is used in

a[::-1]

means that for a given string/list/tuple, you can slice the said object using the format

<object_name>[<start_index>, <stop_index>, <step>]

This means that the object is going to slice every "step" index from the given start index, till the stop index (excluding the stop index) and return it to you.

In case the start index or stop index is missing, it takes up the default value as the start index and stop index of the given string/list/tuple. If the step is left blank, then it takes the default value of 1 i.e it goes through each index.

So,

a = '1234'
print a[::2]

would print

13

Now the indexing here and also the step count, support negative numbers. So, if you give a -1 index, it translates to len(a)-1 index. And if you give -x as the step count, then it would step every x'th value from the start index, till the stop index in the reverse direction. For example

a = '1234'
print a[3:0:-1]

This would return

432

Note, that it doesn't return 4321 because, the stop index is not included.

Now in your case,

str(int(a[::-1]))

would just reverse a given integer, that is stored in a string, and then convert it back to a string

i.e "1234" -> "4321" -> 4321 -> "4321"

If what you are trying to do is just reverse the given string, then simply a[::-1] would work .

Twitter Bootstrap Button Text Word Wrap

You can simply add this class.

.btn {
    white-space:normal !important;
    word-wrap: break-word; 
}

Setting std=c99 flag in GCC

How about alias gcc99= gcc -std=c99?

Java Webservice Client (Best way)

I have had good success using Spring WS for the client end of a web service app - see http://static.springsource.org/spring-ws/sites/1.5/reference/html/client.html

My project uses a combination of:

  • XMLBeans (generated from a simple Maven job using the xmlbeans-maven-plugin)

  • Spring WS - using marshalSendAndReceive() reduces the code down to one line for sending and receiving

  • some Dozer - mapping the complex XMLBeans to simple beans for the client GUI

dictionary update sequence element #0 has length 3; 2 is required

This error raised up because you trying to update dict object by using a wrong sequence (list or tuple) structure.

cash_id.create(cr, uid, lines,context=None) trying to convert lines into dict object:

(0, 0, {
    'name': l.name,
    'date': l.date,
    'amount': l.amount,
    'type': l.type,
    'statement_id': exp.statement_id.id,
    'account_id': l.account_id.id,
    'account_analytic_id': l.analytic_account_id.id,
    'ref': l.ref,
    'note': l.note,
    'company_id': l.company_id.id
})

Remove the second zero from this tuple to properly convert it into a dict object.

To test it your self, try this into python shell:

>>> l=[(0,0,{'h':88})]
>>> a={}
>>> a.update(l)

Traceback (most recent call last):
  File "<pyshell#11>", line 1, in <module>
    a.update(l)
ValueError: dictionary update sequence element #0 has length 3; 2 is required

>>> l=[(0,{'h':88})]
>>> a.update(l)

Question mark and colon in JavaScript

? : isn't this the ternary operator?

var x= expression ? true:false

How to unblock with mysqladmin flush hosts

mysqladmin is not a SQL statement. It's a little helper utility program you'll find on your MySQL server... and "flush-hosts" is one of the things it can do. ("status" and "shutdown" are a couple of other things that come to mind).

You type that command from a shell prompt.

Alternately, from your query browser (such as phpMyAdmin), the SQL statement you're looking for is simply this:

FLUSH HOSTS;

http://dev.mysql.com/doc/refman/5.6/en/flush.html

http://dev.mysql.com/doc/refman/5.6/en/mysqladmin.html

How to delete duplicates on a MySQL table?

There are just a few basic steps when removing duplicate data from your table:

  • Back up your table!
  • Find the duplicate rows
  • Remove the duplicate rows

Here is the full tutorial: https://blog.teamsql.io/deleting-duplicate-data-3541485b3473

How to center the text in a JLabel?

The following constructor, JLabel(String, int), allow you to specify the horizontal alignment of the label.

JLabel label = new JLabel("The Label", SwingConstants.CENTER);

How do I configure git to ignore some files locally?

this is a kind of brief solution,that add a row to local exclude file.

 echo YOURFILE_OR_DIRECTOY >> .git/info/exclude 

Rename Oracle Table or View

Past 10g the current answer no longer works for renaming views. The only method that still works is dropping and recreating the view. The best way I can think of to do this would be:

SELECT TEXT FROM ALL_VIEWS WHERE owner='some_schema' and VIEW_NAME='some_view';

Add this in front of the SQL returned

Create or replace view some_schema.new_view_name as ...

Drop the old view

Drop view some_schema.some_view;

Is a Java hashmap search really O(1)?

A particular feature of a HashMap is that unlike, say, balanced trees, its behavior is probabilistic. In these cases its usually most helpful to talk about complexity in terms of the probability of a worst-case event occurring would be. For a hash map, that of course is the case of a collision with respect to how full the map happens to be. A collision is pretty easy to estimate.

pcollision = n / capacity

So a hash map with even a modest number of elements is pretty likely to experience at least one collision. Big O notation allows us to do something more compelling. Observe that for any arbitrary, fixed constant k.

O(n) = O(k * n)

We can use this feature to improve the performance of the hash map. We could instead think about the probability of at most 2 collisions.

pcollision x 2 = (n / capacity)2

This is much lower. Since the cost of handling one extra collision is irrelevant to Big O performance, we've found a way to improve performance without actually changing the algorithm! We can generalzie this to

pcollision x k = (n / capacity)k

And now we can disregard some arbitrary number of collisions and end up with vanishingly tiny likelihood of more collisions than we are accounting for. You could get the probability to an arbitrarily tiny level by choosing the correct k, all without altering the actual implementation of the algorithm.

We talk about this by saying that the hash-map has O(1) access with high probability

Detect Safari browser

For the records, the safest way I've found is to implement the Safari part of the browser-detection code from this answer:

const isSafari = window['safari'] && safari.pushNotification &&
    safari.pushNotification.toString() === '[object SafariRemoteNotification]';

Of course, the best way of dealing with browser-specific issues is always to do feature-detection, if at all possible. Using a piece of code like the above one is, though, still better than agent string detection.

What is the current choice for doing RPC in Python?

You could try Ladon. It serves up multiple web server protocols at once so you can offer more flexibility at the client side.

http://pypi.python.org/pypi/ladon

How to extract hours and minutes from a datetime.datetime object?

If the time is 11:03, then the accepted answer will print 11:3.

You could zero-pad the minutes:

"Created at {:d}:{:02d}".format(tdate.hour, tdate.minute)

Or go another way and use tdate.time() and only take the hour/minute part:

str(tdate.time())[0:5]

Replace preg_replace() e modifier with preg_replace_callback

In a regular expression, you can "capture" parts of the matched string with (brackets); in this case, you are capturing the (^|_) and ([a-z]) parts of the match. These are numbered starting at 1, so you have back-references 1 and 2. Match 0 is the whole matched string.

The /e modifier takes a replacement string, and substitutes backslash followed by a number (e.g. \1) with the appropriate back-reference - but because you're inside a string, you need to escape the backslash, so you get '\\1'. It then (effectively) runs eval to run the resulting string as though it was PHP code (which is why it's being deprecated, because it's easy to use eval in an insecure way).

The preg_replace_callback function instead takes a callback function and passes it an array containing the matched back-references. So where you would have written '\\1', you instead access element 1 of that parameter - e.g. if you have an anonymous function of the form function($matches) { ... }, the first back-reference is $matches[1] inside that function.

So a /e argument of

'do_stuff(\\1) . "and" . do_stuff(\\2)'

could become a callback of

function($m) { return do_stuff($m[1]) . "and" . do_stuff($m[2]); }

Or in your case

'strtoupper("\\2")'

could become

function($m) { return strtoupper($m[2]); }

Note that $m and $matches are not magic names, they're just the parameter name I gave when declaring my callback functions. Also, you don't have to pass an anonymous function, it could be a function name as a string, or something of the form array($object, $method), as with any callback in PHP, e.g.

function stuffy_callback($things) {
    return do_stuff($things[1]) . "and" . do_stuff($things[2]);
}
$foo = preg_replace_callback('/([a-z]+) and ([a-z]+)/', 'stuffy_callback', 'fish and chips');

As with any function, you can't access variables outside your callback (from the surrounding scope) by default. When using an anonymous function, you can use the use keyword to import the variables you need to access, as discussed in the PHP manual. e.g. if the old argument was

'do_stuff(\\1, $foo)'

then the new callback might look like

function($m) use ($foo) { return do_stuff($m[1], $foo); }

Gotchas

  • Use of preg_replace_callback is instead of the /e modifier on the regex, so you need to remove that flag from your "pattern" argument. So a pattern like /blah(.*)blah/mei would become /blah(.*)blah/mi.
  • The /e modifier used a variant of addslashes() internally on the arguments, so some replacements used stripslashes() to remove it; in most cases, you probably want to remove the call to stripslashes from your new callback.

Use JavaScript to place cursor at end of text in text input element

Super easy (you may have to focus on the input element)

inputEl = getElementById('inputId');
var temp = inputEl.value;
inputEl.value = '';
inputEl.value = temp;

How can I list the scheduled jobs running in my database?

The DBA views are restricted. So you won't be able to query them unless you're connected as a DBA or similarly privileged user.

The ALL views show you the information you're allowed to see. Normally that would be jobs you've submitted, unless you have additional privileges.

The privileges you need are defined in the Admin Guide. Find out more.

So, either you need a DBA account or you need to chat with your DBA team about getting access to the information you need.

HTML text input field with currency symbol

_x000D_
_x000D_
.currencyinput {_x000D_
    border: 1px inset #ccc;_x000D_
    padding-bottom: 1px;//FOR IE & Chrome_x000D_
}_x000D_
.currencyinput input {_x000D_
    border: 0;_x000D_
}
_x000D_
<span class="currencyinput">$<input type="text" name="currency"></span>
_x000D_
_x000D_
_x000D_

Check if string is neither empty nor space in shell script

Another quick test for a string to have something in it but space.

if [[ -n "${str// /}" ]]; then
    echo "It is not empty!"
fi

"-n" means non-zero length string.

Then the first two slashes mean match all of the following, in our case space(s). Then the third slash is followed with the replacement (empty) string and closed with "}". Note the difference from the usual regular expression syntax.

You can read more about string manipulation in bash shell scripting here.

Find the 2nd largest element in an array with minimum number of comparisons

Suppose provided array is inPutArray = [1,2,5,8,7,3] expected O/P -> 7 (second largest)

 take temp array 
      temp = [0,0], int dummmy=0;
    for (no in inPutArray) {
    if(temp[1]<no)
     temp[1] = no
     if(temp[0]<temp[1]){
    dummmy = temp[0]
    temp[0] = temp[1]
    temp[1] = temp
      }
    }

    print("Second largest no is %d",temp[1])

How to create a responsive image that also scales up in Bootstrap 3

Bootstrap's responsive image class sets max-width to 100%. This limits its size, but does not force it to stretch to fill parent elements larger than the image itself. You'd have to use the width attribute to force upscaling.

http://getbootstrap.com/css/#images-responsive

Is there a way to crack the password on an Excel VBA Project?

For Excel 2007 onward you need to change your file extension to .zip In the archive there is a subfolder xl, in there you will find vbaProject.bin. Follow the step above with vbaProject.bin then save it back in the archive. Modify back your extension and voilà! (meaning follow steps above)

Fix Access denied for user 'root'@'localhost' for phpMyAdmin

xampp\phpMyAdmin/config.inc

Find-

$cfg['Servers'][$i]['auth_type'] = 'config'

and change the 'config' to 'http' and that will allow you to type the user name and password when you go to your phpMyAdmin page using your browser.

How to debug stored procedures with print statements?

If you're using MSSQL Server management studio print statements will print out under the messages tab not under the Results tab.

enter image description here

Print statements will appear there.

How do I break out of a loop in Scala?

import scala.util.control._

object demo_brk_963 
{
   def main(args: Array[String]) 
   {
      var a = 0;
      var b = 0;
      val numList1 = List(1,2,3,4,5,6,7,8,9,10);
      val numList2 = List(11,12,13);

      val outer = new Breaks; //object for break
      val inner = new Breaks; //object for break

      outer.breakable // Outer Block
      {
         for( a <- numList1)
         {
            println( "Value of a: " + a);

            inner.breakable // Inner Block
            {
               for( b <- numList2)
               {
                  println( "Value of b: " + b);

                  if( b == 12 )
                  {
                      println( "break-INNER;");
                       inner.break;
                  }
               }
            } // inner breakable
            if( a == 6 )
            {
                println( "break-OUTER;");
                outer.break;
            }
         }
      } // outer breakable.
   }
}

Basic method to break the loop, using Breaks class. By declaring the loop as breakable.

Access POST values in Symfony2 request object

I think that in order to get the request data, bound and validated by the form object, you must use :

$form->getClientData();

How do I interpret precision and scale of a number in a database?

Numeric precision refers to the maximum number of digits that are present in the number.

ie 1234567.89 has a precision of 9

Numeric scale refers to the maximum number of decimal places

ie 123456.789 has a scale of 3

Thus the maximum allowed value for decimal(5,2) is 999.99

App.Config Transformation for projects which are not Web Projects in Visual Studio?

I tried several solutions and here is the simplest I personally found.
Dan pointed out in the comments that the original post belongs to Oleg Sychthanks, Oleg!

Here are the instructions:

1. Add an XML file for each configuration to the project.

Typically you will have Debug and Release configurations so name your files App.Debug.config and App.Release.config. In my project, I created a configuration for each kind of environment, so you might want to experiment with that.

2. Unload project and open .csproj file for editing

Visual Studio allows you to edit .csproj files right in the editor—you just need to unload the project first. Then right-click on it and select Edit <ProjectName>.csproj.

3. Bind App.*.config files to main App.config

Find the project file section that contains all App.config and App.*.config references. You'll notice their build actions are set to None:

<None Include="App.config" />
<None Include="App.Debug.config" />
<None Include="App.Release.config" />

First, set build action for all of them to Content.
Next, make all configuration-specific files dependant on the main App.config so Visual Studio groups them like it does designer and code-behind files.

Replace XML above with the one below:

<Content Include="App.config" />
<Content Include="App.Debug.config" >
  <DependentUpon>App.config</DependentUpon>
</Content>
<Content Include="App.Release.config" >
  <DependentUpon>App.config</DependentUpon>
</Content>

4. Activate transformations magic (only necessary for Visual Studio versions pre VS2017)

In the end of file after

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

and before final

</Project>

insert the following XML:

  <UsingTask TaskName="TransformXml" AssemblyFile="$(MSBuildExtensionsPath)\Microsoft\VisualStudio\v$(VisualStudioVersion)\Web\Microsoft.Web.Publishing.Tasks.dll" />
  <Target Name="CoreCompile" Condition="exists('app.$(Configuration).config')">
    <!-- Generate transformed app config in the intermediate directory -->
    <TransformXml Source="app.config" Destination="$(IntermediateOutputPath)$(TargetFileName).config" Transform="app.$(Configuration).config" />
    <!-- Force build process to use the transformed configuration file from now on. -->
    <ItemGroup>
      <AppConfigWithTargetPath Remove="app.config" />
      <AppConfigWithTargetPath Include="$(IntermediateOutputPath)$(TargetFileName).config">
        <TargetPath>$(TargetFileName).config</TargetPath>
      </AppConfigWithTargetPath>
    </ItemGroup>
  </Target>

Now you can reload the project, build it and enjoy App.config transformations!

FYI

Make sure that your App.*.config files have the right setup like this:

<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
     <!--magic transformations here-->
</configuration>

vertical-align: middle doesn't work

You should set a fixed value to your span's line-height property:

.float, .twoline {
    line-height: 100px;
}

How to check if keras tensorflow backend is GPU or CPU version?

According to the documentation.

If you are running on the TensorFlow or CNTK backends, your code will automatically run on GPU if any available GPU is detected.

You can check what all devices are used by tensorflow by -

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

Also as suggested in this answer

import tensorflow as tf
sess = tf.Session(config=tf.ConfigProto(log_device_placement=True))

This will print whether your tensorflow is using a CPU or a GPU backend. If you are running this command in jupyter notebook, check out the console from where you have launched the notebook.

If you are sceptic whether you have installed the tensorflow gpu version or not. You can install the gpu version via pip.

pip install tensorflow-gpu

VBA changing active workbook

Use ThisWorkbook which will refer to the original workbook which holds the code.

Alternatively at code start

Dim Wb As Workbook
Set Wb = ActiveWorkbook

sample code that activates all open books before returning to ThisWorkbook

Sub Test()
Dim Wb As Workbook
Dim Wb2 As Workbook
Set Wb = ThisWorkbook
For Each Wb2 In Application.Workbooks
    Wb2.Activate
Next
Wb.Activate
End Sub

Using a dispatch_once singleton model in Swift

First solution

let SocketManager = SocketManagerSingleton();

class SocketManagerSingleton {

}

Later in your code:

func someFunction() {        
    var socketManager = SocketManager        
}

Second solution

func SocketManager() -> SocketManagerSingleton {
    return _SocketManager
}
let _SocketManager = SocketManagerSingleton();

class SocketManagerSingleton {

}

And later in your code you will be able to keep braces for less confusion:

func someFunction() {        
    var socketManager = SocketManager()        
}

How to set default vim colorscheme

Put a colorscheme directive in your .vimrc file, for example:

colorscheme morning

See here: http://vim.wikia.com/wiki/Change_the_color_scheme

How to get table list in database, using MS SQL 2008?

This query will get you all the tables in the database

USE [DatabaseName];

SELECT * FROM information_schema.tables;

How to format strings in Java

Take a look at String.format. Note, however, that it takes format specifiers similar to those of C's printf family of functions -- for example:

String.format("Hello %s, %d", "world", 42);

Would return "Hello world, 42". You may find this helpful when learning about the format specifiers. Andy Thomas-Cramer was kind enough to leave this link in a comment below, which appears to point to the official spec. The most commonly used ones are:

  • %s - insert a string
  • %d - insert a signed integer (decimal)
  • %f - insert a real number, standard notation

This is radically different from C#, which uses positional references with an optional format specifier. That means that you can't do things like:

String.format("The {0} is repeated again: {0}", "word");

... without actually repeating the parameter passed to printf/format. (see The Scrum Meister's comment below)


If you just want to print the result directly, you may find System.out.printf (PrintStream.printf) to your liking.

Can I position an element fixed relative to parent?

2016 Update

It's now possible in modern browsers to position an element fixed relative to its container. An element that has a transform property acts as the viewport for any of its fixed position child elements.

Or as the CSS Transforms Module puts it:

For elements whose layout is governed by the CSS box model, any value other than none for the transform property also causes the element to establish a containing block for all descendants. Its padding box will be used to layout for all of its absolute-position descendants, fixed-position descendants, and descendant fixed background attachments.

_x000D_
_x000D_
.context {_x000D_
  width: 300px;_x000D_
  height: 250px;_x000D_
  margin: 100px;_x000D_
  transform: translateZ(0);_x000D_
}_x000D_
.viewport {_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
  border: 1px solid black;_x000D_
  overflow: scroll;_x000D_
}_x000D_
.centered {_x000D_
  position: fixed;_x000D_
  left: 50%;_x000D_
  bottom: 15px;_x000D_
  transform: translateX(-50%);_x000D_
}
_x000D_
<div class="context">_x000D_
  <div class="viewport">_x000D_
    <div class="canvas">_x000D_
_x000D_
      <table>_x000D_
        <tr>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
        </tr>_x000D_
        <tr>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
        </tr>_x000D_
_x000D_
        <tr>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
        </tr>_x000D_
_x000D_
        <tr>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
          <td>stuff</td>_x000D_
        </tr>_x000D_
      </table>_x000D_
_x000D_
      <button class="centered">OK</button>_x000D_
_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to print something to the console in Xcode?

@Logan has put this perfectly. Potentially something worth pointing out also is that you can use

printf(whatever you want to print);

For example if you were printing a string:

printf("hello");

How to get the clicked link's href with jquery?

Suppose we have three anchor tags like ,

<a  href="ID=1" class="testClick">Test1.</a>
<br />
<a  href="ID=2" class="testClick">Test2.</a>
<br />
<a  href="ID=3" class="testClick">Test3.</a>

now in script

$(".testClick").click(function () {
        var anchorValue= $(this).attr("href");
        alert(anchorValue);
});

use this keyword instead of className (testClick)

MongoDB: update every document on one field

I have been using MongoDB .NET driver for a little over a month now. If I were to do it using .NET driver, I would use Update method on the collection object. First, I will construct a query that will get me all the documents I am interested in and do an Update on the fields I want to change. Update in Mongo only affects the first document and to update all documents resulting from the query one needs to use 'Multi' update flag. Sample code follows...

var collection = db.GetCollection("Foo");
var query = Query.GTE("No", 1); // need to construct in such a way that it will give all 20K //docs.
var update = Update.Set("timestamp", datetime.UtcNow);
collection.Update(query, update, UpdateFlags.Multi);

How to bind an enum to a combobox control in WPF?

Use ObjectDataProvider:

<ObjectDataProvider x:Key="enumValues"
   MethodName="GetValues" ObjectType="{x:Type System:Enum}">
      <ObjectDataProvider.MethodParameters>
           <x:Type TypeName="local:ExampleEnum"/>
      </ObjectDataProvider.MethodParameters>
 </ObjectDataProvider>

and then bind to static resource:

ItemsSource="{Binding Source={StaticResource enumValues}}"

based on this article

Efficient way to remove keys with empty strings from a dict

If you want a full-featured, yet succinct approach to handling real-world data structures which are often nested, and can even contain cycles, I recommend looking at the remap utility from the boltons utility package.

After pip install boltons or copying iterutils.py into your project, just do:

from boltons.iterutils import remap

drop_falsey = lambda path, key, value: bool(value)
clean = remap(metadata, visit=drop_falsey)

This page has many more examples, including ones working with much larger objects from Github's API.

It's pure-Python, so it works everywhere, and is fully tested in Python 2.7 and 3.3+. Best of all, I wrote it for exactly cases like this, so if you find a case it doesn't handle, you can bug me to fix it right here.

Insert new column into table in sqlite?

You don't add columns between other columns in SQL, you just add them. Where they're put is totally up to the DBMS. The right place to ensure that columns come out in the correct order is when you select them.

In other words, if you want them in the order {name,colnew,qty,rate}, you use:

select name, colnew, qty, rate from ...

With SQLite, you need to use alter table, an example being:

alter table mytable add column colnew char(50)

What is the difference between Linear search and Binary search?

binary search runs in O(logn) time whereas linear search runs in O(n) times thus binary search has better performance

Binding multiple events to a listener (without JQuery)?

I have a simpler solution for you:

window.onload = window.onresize = (event) => {
    //Your Code Here
}

I've tested this an it works great, on the plus side it's compact and uncomplicated like the other examples here.

SQL Query to add a new column after an existing column in SQL Server 2005

It's possible.

First, just add each column the usual way (as the last column).

Secondly, in SQL Server Management Studio Get into Tools => Options.

Under 'Designers' Tab => 'Table and Database Designers' menu, uncheck the option 'Prevent saving changes that require table re-creation'.

Afterwards, right click on your table and choose 'Design'. In 'Design' mode just drag the columns to order them.

Don't forget to save.

how to put focus on TextBox when the form load?

Textbox.Focus() "Tries" to set focus on the textbox element. In case of the element visibility is hidden for example, Focus() will not work. So make sure that your element is visible before calling Focus().

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

Visual Studio 2015/2017's live debugger is injecting code that contains the deprecated call.

How to name variables on the fly?

Another tricky solution is to name elements of list and attach it:

list_name = list(
    head(iris),
    head(swiss),
    head(airquality)
    )

names(list_name) <- paste("orca", seq_along(list_name), sep="")
attach(list_name)

orca1
#   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
# 1          5.1         3.5          1.4         0.2  setosa
# 2          4.9         3.0          1.4         0.2  setosa
# 3          4.7         3.2          1.3         0.2  setosa
# 4          4.6         3.1          1.5         0.2  setosa
# 5          5.0         3.6          1.4         0.2  setosa
# 6          5.4         3.9          1.7         0.4  setosa

Should have subtitle controller already set Mediaplayer error Android

To remove message on logcat, i add a subtitle to track. On windows, right click on track -> Property -> Details -> insert a text on subtitle. Done :)

How do I create a constant in Python?

from enum import Enum
class StringConsts(str,Enum):
    ONE='one'
    TWO='two'

print(f'Truth is  {StringConsts.ONE=="one"}') #Truth is True
StringConsts.ONE="one" #Error: Cannot reassign

This mixin of Enum and str gives you the power of not having to reimplement setattr (through Enum) and comparison to other str objects (through str).

This might deprecate http://code.activestate.com/recipes/65207-constants-in-python/?in=user-97991 completely.

Is it possible to move/rename files in Git and maintain their history?

I would like to rename/move a project subtree in Git moving it from

/project/xyz

to

/components/xyz

If I use a plain git mv project components, then all the commit history for the xyz project gets lost.

No (8 years later, Git 2.19, Q3 2018), because Git will detect the directory rename, and this is now better documented.

See commit b00bf1c, commit 1634688, commit 0661e49, commit 4d34dff, commit 983f464, commit c840e1a, commit 9929430 (27 Jun 2018), and commit d4e8062, commit 5dacd4a (25 Jun 2018) by Elijah Newren (newren).
(Merged by Junio C Hamano -- gitster -- in commit 0ce5a69, 24 Jul 2018)

That is now explained in Documentation/technical/directory-rename-detection.txt:

Example:

When all of x/a, x/b and x/c have moved to z/a, z/b and z/c, it is likely that x/d added in the meantime would also want to move to z/d by taking the hint that the entire directory 'x' moved to 'z'.

But they are many other cases, like:

one side of history renames x -> z, and the other renames some file to x/e, causing the need for the merge to do a transitive rename.

To simplify directory rename detection, those rules are enforced by Git:

a couple basic rules limit when directory rename detection applies:

  1. If a given directory still exists on both sides of a merge, we do not consider it to have been renamed.
  2. If a subset of to-be-renamed files have a file or directory in the way (or would be in the way of each other), "turn off" the directory rename for those specific sub-paths and report the conflict to the user.
  3. If the other side of history did a directory rename to a path that your side of history renamed away, then ignore that particular rename from the other side of history for any implicit directory renames (but warn the user).

You can see a lot of tests in t/t6043-merge-rename-directories.sh, which also point out that:

  • a) If renames split a directory into two or more others, the directory with the most renames, "wins".
  • b) Avoid directory-rename-detection for a path, if that path is the source of a rename on either side of a merge.
  • c) Only apply implicit directory renames to directories if the other side of history is the one doing the renaming.

TypeError: 'function' object is not subscriptable - Python

You can use this:

bankHoliday= [1, 0, 1, 1, 2, 0, 0, 1, 0, 0, 0, 2] #gives the list of bank holidays in each month

def bank_holiday(month):
   month -= 1#Takes away the numbers from the months, as months start at 1 (January) not at 0. There is no 0 month.
   print(bankHoliday[month])

bank_holiday(int(input("Which month would you like to check out: ")))

How to block calls in android

You can do it by listening to phone call events . You do it by having a BroadcastReceiver to PHONE_STATE and to NEW_OUTGOING_CALL. You find there what is the phone number.

Then when you decide to end the call, this is a bit tricky, because only from Android P it's guaranteed to work. Check here.

How to get previous page url using jquery

Do you mean something like history.go(-1);? It will go back to the previous page.

window.history on MDN

Can I install Python 3.x and 2.x on the same Windows computer?

You should make sure that the PATH environment variable doesn't contain both python.exe files ( add the one you're currently using to run scripts on a day to day basis ) , or do as Kniht suggested with the batch files . Aside from that , I don't see why not .

P.S : I have 2.6 installed as my "primary" python and 3.0 as my "play" python . The 2.6 is included in the PATH . Everything works fine .

List all devices, partitions and volumes in Powershell

You can also do it on the CLI with

net use

How do I install PHP cURL on Linux Debian?

I wrote an article on topis how to [manually install curl on debian linu][1]x.

[1]: http://www.jasom.net/how-to-install-curl-command-manually-on-debian-linux. This is its shortcut:

  1. cd /usr/local/src
  2. wget http://curl.haxx.se/download/curl-7.36.0.tar.gz
  3. tar -xvzf curl-7.36.0.tar.gz
  4. rm *.gz
  5. cd curl-7.6.0
  6. ./configure
  7. make
  8. make install

And restart Apache. If you will have an error during point 6, try to run apt-get install build-essential.

convert '1' to '0001' in JavaScript

String.prototype.padZero= function(len, c){
    var s= this, c= c || '0';
    while(s.length< len) s= c+ s;
    return s;
}

dispite the name, you can left-pad with any character, including a space. I never had a use for right side padding, but that would be easy enough.

How to return a file (FileContentResult) in ASP.NET WebAPI

Here is an implementation that streams the file's content out without buffering it (buffering in byte[] / MemoryStream, etc. can be a server problem if it's a big file).

public class FileResult : IHttpActionResult
{
    public FileResult(string filePath)
    {
        if (filePath == null)
            throw new ArgumentNullException(nameof(filePath));

        FilePath = filePath;
    }

    public string FilePath { get; }

    public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
    {
        var response = new HttpResponseMessage(HttpStatusCode.OK);
        response.Content = new StreamContent(File.OpenRead(FilePath));
        var contentType = MimeMapping.GetMimeMapping(Path.GetExtension(FilePath));
        response.Content.Headers.ContentType = new MediaTypeHeaderValue(contentType);
        return Task.FromResult(response);
    }
}

It can be simply used like this:

public class MyController : ApiController
{
    public IHttpActionResult Get()
    {
        string filePath = GetSomeValidFilePath();
        return new FileResult(filePath);
    }
}

Full Page <iframe>

This is cross-browser and fully responsive:

<iframe
  src="https://drive.google.com/file/d/0BxrMaW3xINrsR3h2cWx0OUlwRms/preview"
  style="
    position: fixed;
    top: 0px;
    bottom: 0px;
    right: 0px;
    width: 100%;
    border: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    z-index: 999999;
    height: 100%;
  ">
</iframe>

Where Is Machine.Config?

You can run this in powershell:

[System.Runtime.InteropServices.RuntimeEnvironment]::SystemConfigurationFile

Which outputs this for .net 4:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config

Note however that this might change depending on whether .net is running as 32 or 64 bit which will result in \Framework\ or \Framework64\ respectively.

Oracle date to string conversion

Try this. Oracle has this feature to distinguish the millennium years..

As you mentioned, if your column is a varchar, then the below query will yield you 1989..

select to_date(column_name,'dd/mm/rr') from table1;

When the format rr is used in year, the following would be done by oracle.

if rr->00 to 49 ---> result will be 2000 - 2049, if rr->50 to 99 ---> result will be 1950 - 1999

SSIS Excel Connection Manager failed to Connect to the Source

I faced the same issue. I think @Rishit answer helped me. This issue is related to 32 bit/ 64 bit version of driver. I was trying to read .xlsx files to SQL Server tables using SSIS

  • My machine was pre-installed with Office 2016 64 bit on Win 10 machine along with MS Access
  • I was able to read excel 97-2003 (.xls) files using ssis, but unable to connect .xlsx files
  • My requirement was to read .xlsx files
  • Installed AccessDatabaseEngine_X64 to read xlsx, that given me the following error:

enter image description here

  • I uninstalled the AccessDatabaseEngine_X64 and installed AccessDatabaseEngine 32 bit, that resolved the issue

What is the meaning of "Failed building wheel for X" in pip install?

I would like to add that if you only have Python3 on your system then you need to start using pip3 instead of pip.

You can install pip3 using the following command;

sudo apt install python3-pip -y

After this you can try to install the package you need with;

sudo pip3 install <package>

Iterating over every two elements in a list

With unpacking:

l = [1,2,3,4,5,6]
while l:
    i, k, *l = l
    print(f'{i}+{k}={i+k}') 

Note: this will consume l, leaving it empty afterward.

How to change menu item text dynamically in Android

You better use the override onPrepareOptionsMenu

menu.Clear ();
   if (TabActual == TabSelec.Anuncio)
   {
       menu.Add(10, 11, 0, "Crear anuncio");
       menu.Add(10, 12, 1, "Modificar anuncio");
       menu.Add(10, 13, 2, "Eliminar anuncio");
       menu.Add(10, 14, 3, "Actualizar");
   }
   if (TabActual == TabSelec.Fotos)
   {
       menu.Add(20, 21, 0, "Subir foto");
       menu.Add(20, 22, 1, "Actualizar");
   }
   if (TabActual == TabSelec.Comentarios)
   {
       menu.Add(30, 31, 0, "Actualizar");
   }

Here an example

Automatically size JPanel inside JFrame

You need to set a layout manager for the JFrame to use - This deals with how components are positioned. A useful one is the BorderLayout manager.

Simply adding the following line of code should fix your problems:

mainFrame.setLayout(new BorderLayout());

(Do this before adding components to the JFrame)

Hibernate Union alternatives

I have to agree with Vladimir. I too looked into using UNION in HQL and couldn't find a way around it. The odd thing was that I could find (in the Hibernate FAQ) that UNION is unsupported, bug reports pertaining to UNION marked 'fixed', newsgroups of people saying that the statements would be truncated at UNION, and other newsgroups of people reporting it works fine... After a day of mucking with it, I ended up porting my HQL back to plain SQL, but doing it in a View in the database would be a good option. In my case, parts of the query were dynamically generated, so I had to build the SQL in the code instead.

Replacing accented characters php

I have tried all sorts based on the variations listed in the answers, but the following worked:

$unwanted_array = array(    'Š'=>'S', 'š'=>'s', 'Ž'=>'Z', 'ž'=>'z', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'A', 'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E',
                            'Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U',
                            'Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a', 'æ'=>'a', 'ç'=>'c',
                            'è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i', 'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o',
                            'ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'ý'=>'y', 'þ'=>'b', 'ÿ'=>'y' );
$str = strtr( $str, $unwanted_array );

How to allow users to check for the latest app version from inside the app?

Here's how to find the current and latest available versions:

       try {
            String curVersion = getPackageManager().getPackageInfo(getPackageName(), 0).versionName;
            String newVersion = curVersion;
            newVersion = Jsoup.connect("https://play.google.com/store/apps/details?id=" + getPackageName() + "&hl=en")
                    .timeout(30000)
                    .userAgent("Mozilla/5.0 (Windows; U; WindowsNT 5.1; en-US; rv1.8.1.6) Gecko/20070725 Firefox/2.0.0.6")
                    .referrer("http://www.google.com")
                    .get()
                    .select("div.hAyfc:nth-child(4) .IQ1z0d .htlgb")
                    .first()
                    .ownText();
            Log.d("Curr Version" , curVersion);
            Log.d("New Version" , newVersion);

        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }

How can I declare a Boolean parameter in SQL statement?

The same way you declare any other variable, just use the bit type:

DECLARE @MyVar bit
Set @MyVar = 1  /* True */
Set @MyVar = 0  /* False */

SELECT * FROM [MyTable] WHERE MyBitColumn = @MyVar

Is a new line = \n OR \r\n?

If you are programming in PHP, it is useful to split lines by \n and then trim() each line (provided you don't care about whitespace) to give you a "clean" line regardless.

foreach($line in explode("\n", $data))
{
    $line = trim($line);
    ...
}

How to concatenate two MP4 files using FFmpeg?

From the documentation here: https://trac.ffmpeg.org/wiki/Concatenate

If you have MP4 files, these could be losslessly concatenated by first transcoding them to MPEG-2 transport streams. With H.264 video and AAC audio, the following can be used:

ffmpeg -i input1.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
ffmpeg -i input2.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts
ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy -bsf:a aac_adtstoasc output.mp4

This approach works on all platforms.

I needed the ability to encapsulate this in a cross platform script, so I used fluent-ffmpeg and came up with the following solution:

const unlink = path =>
  new Promise((resolve, reject) =>
    fs.unlink(path, err => (err ? reject(err) : resolve()))
  )

const createIntermediate = file =>
  new Promise((resolve, reject) => {
    const out = `${Math.random()
      .toString(13)
      .slice(2)}.ts`

    ffmpeg(file)
      .outputOptions('-c', 'copy', '-bsf:v', 'h264_mp4toannexb', '-f', 'mpegts')
      .output(out)
      .on('end', () => resolve(out))
      .on('error', reject)
      .run()
  })

const concat = async (files, output) => {
  const names = await Promise.all(files.map(createIntermediate))
  const namesString = names.join('|')

  await new Promise((resolve, reject) =>
    ffmpeg(`concat:${namesString}`)
      .outputOptions('-c', 'copy', '-bsf:a', 'aac_adtstoasc')
      .output(output)
      .on('end', resolve)
      .on('error', reject)
      .run()
  )

  names.map(unlink)
}

concat(['file1.mp4', 'file2.mp4', 'file3.mp4'], 'output.mp4').then(() =>
  console.log('done!')
)

Android and setting alpha for (image) view alpha

It's easier than the other response. There is an xml value alpha that takes double values.

android:alpha="0.0" thats invisible

android:alpha="0.5" see-through

android:alpha="1.0" full visible

That's how it works.

Regex pattern inside SQL Replace function?

Instead of stripping out the found character by its sole position, using Replace(Column, BadFoundCharacter, '') could be substantially faster. Additionally, instead of just replacing the one bad character found next in each column, this replaces all those found.

WHILE 1 = 1 BEGIN
    UPDATE dbo.YourTable
    SET Column = Replace(Column, Substring(Column, PatIndex('%[^0-9.-]%', Column), 1), '')
    WHERE Column LIKE '%[^0-9.-]%'
    If @@RowCount = 0 BREAK;
END;

I am convinced this will work better than the accepted answer, if only because it does fewer operations. There are other ways that might also be faster, but I don't have time to explore those right now.

How can I color a UIImage in Swift?

Swift 4.

Use this extension to create a solid colored image

extension UIImage {   

    public func coloredImage(color: UIColor) -> UIImage? {
        return coloredImage(color: color, size: CGSize(width: 1, height: 1))
    }

    public func coloredImage(color: UIColor, size: CGSize) -> UIImage? {

        UIGraphicsBeginImageContextWithOptions(size, false, 0)

        color.setFill()
        UIRectFill(CGRect(origin: CGPoint(), size: size))

        guard let image = UIGraphicsGetImageFromCurrentImageContext() else { return nil }
        UIGraphicsEndImageContext()

        return image
    }
}

Install gitk on Mac

Correct, the 1.7.12.4 (Apple Git-37) does not come with gitk. You can install a more recent version of git + git-ui as a separate formula by using brew. More thorough instructions located here: http://www.moncefbelyamani.com/how-to-install-xcode-homebrew-git-rvm-ruby-on-mac/ (see this commit extracting git-gui/gitk into its own formula: https://github.com/Homebrew/homebrew-core/commit/dfa3ccf1e7d3901e371b5140b935839ba9d8b706)

Run the following commands at the terminal:

brew update
brew install git
brew install git-gui

If you get an error indicating it could not link git, then you may need to change permissions/owners of the files it mentions.

Once completed, run:

type -a git

And make sure it shows:

/usr/local/bin/git

If it does not, run:

brew doctor

And make the path change to put /usr/local/bin earlier in the path. Now, gitk should be on your path (along with an updated version of git).

How to embed a Facebook page's feed into my website

For website developers, another option you have is to follow a working Facebook Graph API tutorial such as this one.

But if you need a quick solution where you can customize and embed a Facebook page feed instantly, you should use website plugins such as this one.

Here's a step by step guide:

  1. Get a Free Key or Paid Key.
  2. Go to this login page and use the key to login.
  3. Once logged in, click “+ Create Custom Feed” button.
  4. On the pop up, name your custom Facebook page feed.
  5. On the drop-down, select “Facebook Page Feed On Your Website” option.
  6. Enter your Facebook Page ID.
  7. Click the “Proceed” button. This will show you the customization options.
  8. Click the “ Embed On Website” button located on the upper-right corner of the screen.
  9. On the pop up, copy the embed code by clicking the “Copy Code” button.
  10. Paste the embed code on your website.

Visit the tutorial link to see a live demo there as well.

how do I join two lists using linq or lambda expressions

 public class State
        {
            public int SID { get; set; }
            public string SName { get; set; }
            public string SCode { get; set; }
            public string SAbbrevation { get; set; }
        }

        public class Country
        {
            public int CID { get; set; }
            public string CName { get; set; }
            public string CAbbrevation { get; set; }
        }


 List<State> states = new List<State>()
            {
               new  State{  SID=1,SName="Telangana",SCode="+91",SAbbrevation="TG"},
               new  State{  SID=2,SName="Texas",SCode="512",SAbbrevation="TS"},
            };

            List<Country> coutries = new List<Country>()
            {
               new Country{CID=1,CName="India",CAbbrevation="IND"},
               new Country{CID=2,CName="US of America",CAbbrevation="USA"},
            };

            var res = coutries.Join(states, a => a.CID, b => b.SID, (a, b) => new {a.CName,b.SName}).ToList();

Postman Chrome: What is the difference between form-data, x-www-form-urlencoded and raw

This explains better: Postman docs

Request body

While constructing requests, you would be dealing with the request body editor a lot. Postman lets you send almost any kind of HTTP request (If you can't send something, let us know!). The body editor is divided into 4 areas and has different controls depending on the body type.

form-data

multipart/form-data is the default encoding a web form uses to transfer data. This simulates filling a form on a website, and submitting it. The form-data editor lets you set key/value pairs (using the key-value editor) for your data. You can attach files to a key as well. Do note that due to restrictions of the HTML5 spec, files are not stored in history or collections. You would have to select the file again at the time of sending a request.

urlencoded

This encoding is the same as the one used in URL parameters. You just need to enter key/value pairs and Postman will encode the keys and values properly. Note that you can not upload files through this encoding mode. There might be some confusion between form-data and urlencoded so make sure to check with your API first.

raw

A raw request can contain anything. Postman doesn't touch the string entered in the raw editor except replacing environment variables. Whatever you put in the text area gets sent with the request. The raw editor lets you set the formatting type along with the correct header that you should send with the raw body. You can set the Content-Type header manually as well. Normally, you would be sending XML or JSON data here.

binary

binary data allows you to send things which you can not enter in Postman. For example, image, audio or video files. You can send text files as well. As mentioned earlier in the form-data section, you would have to reattach a file if you are loading a request through the history or the collection.

UPDATE

As pointed out by VKK, the WHATWG spec say urlencoded is the default encoding type for forms.

The invalid value default for these attributes is the application/x-www-form-urlencoded state. The missing value default for the enctype attribute is also the application/x-www-form-urlencoded state.

How to call a View Controller programmatically?

To create a view controller:

UIViewController * vc = [[UIViewController alloc] init];

To call a view controller (must be called from within another viewcontroller):

[self presentViewController:vc animated:YES completion:nil];

For one, use nil rather than null.


Loading a view controller from the storyboard:

NSString * storyboardName = @"MainStoryboard"; 
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil];
UIViewController * vc = [storyboard instantiateViewControllerWithIdentifier:@"IDENTIFIER_OF_YOUR_VIEWCONTROLLER"];
[self presentViewController:vc animated:YES completion:nil];

Identifier of your view controller is either equal to the class name of your view controller, or a Storyboard ID that you can assign in the identity inspector of your storyboard.

Determining if Swift dictionary contains key and obtaining any of its values

My solution for a cache implementation that stores optional NSAttributedString:

public static var attributedMessageTextCache    = [String: NSAttributedString?]()

    if attributedMessageTextCache.index(forKey: "key") != nil
    {
        if let attributedMessageText = TextChatCache.attributedMessageTextCache["key"]
        {
            return attributedMessageText
        }
        return nil
    }

    TextChatCache.attributedMessageTextCache["key"] = .some(.none)
    return nil

push object into array

Well, ["Title", "Ramones"] is an array of strings. But [{"01":"Title", "02", "Ramones"}] is an array of object.

If you are willing to push properties or value into one object, you need to access that object and then push data into that. Example: nietos[indexNumber].yourProperty=yourValue; in real application:

nietos[0].02 = "Ramones";

If your array of object is already empty, make sure it has at least one object, or that object in which you are going to push data to.

Let's say, our array is myArray[], so this is now empty array, the JS engine does not know what type of data does it have, not string, not object, not number nothing. So, we are going to push an object (maybe empty object) into that array. myArray.push({}), or myArray.push({""}).

This will push an empty object into myArray which will have an index number 0, so your exact object is now myArray[0]

Then push property and value into that like this:

myArray[0].property = value;
//in your case:
myArray[0]["01"] = "value";

Deserialize JSON array(or list) in C#

Download Json.NET from here http://james.newtonking.com/projects/json-net.aspx

name deserializedName = JsonConvert.DeserializeObject<name>(jsonData);

jQuery, checkboxes and .is(":checked")

$("#personal").click(function() {
      if ($(this).is(":checked")) {
            alert('Personal');
        /* var validator = $("#register_france").validate(); 
        validator.resetForm(); */
      }
            }
            );

JSFIDDLE

How to clear the text of all textBoxes in the form?

private void CleanForm(Control ctrl)
{
    foreach (var c in ctrl.Controls)
    {
        if (c is TextBox)
        {
            ((TextBox)c).Text = String.Empty;
        }

        if( c.Controls.Count > 0)
        {
           CleanForm(c);
        }
    }
}

When you initially call ClearForm, pass in this, or Page (I assume that is what 'this' is).

best way to create object

There's not really a best way. Both are quite the same, unless you want to do some additional processing using the parameters passed to the constructor during initialization or if you want to ensure a coherent state just after calling the constructor. If it is the case, prefer the first one.

But for readability/maintainability reasons, avoid creating constructors with too many parameters.

In this case, both will do.

Importing a Maven project into Eclipse from Git

Instead of constantly generating project metadata via import->maven command, you can generate your project metadata once and the place it in your git repository along with the rest of your source code. After than, using import->git command will import a proper maven-enabled project, assuming you have maven tools installed.

Make sure to place into the source control system all files in project dir that start with '.' such as .classpath and .project along with the entire contents of the .settings directory.

Recursive query in SQL Server

Something like this (not tested)

with match_groups as (

  select product_id, 
         matching_product_id,
         product_id as group_id
  from matches
  where product_id not in (select matching_product_id from matches)

  union all

  select m.product_id, m.matching_product_id, p.group_id
  from matches m
    join match_groups p on m.product_id = p.matching_product_id
)
select group_id, product_id
from match_groups
order by group_id;

Matplotlib scatterplot; colour as a function of a third variable

Sometimes you may need to plot color precisely based on the x-value case. For example, you may have a dataframe with 3 types of variables and some data points. And you want to do following,

  • Plot points corresponding to Physical variable 'A' in RED.
  • Plot points corresponding to Physical variable 'B' in BLUE.
  • Plot points corresponding to Physical variable 'C' in GREEN.

In this case, you may have to write to short function to map the x-values to corresponding color names as a list and then pass on that list to the plt.scatter command.

x=['A','B','B','C','A','B']
y=[15,30,25,18,22,13]

# Function to map the colors as a list from the input list of x variables
def pltcolor(lst):
    cols=[]
    for l in lst:
        if l=='A':
            cols.append('red')
        elif l=='B':
            cols.append('blue')
        else:
            cols.append('green')
    return cols
# Create the colors list using the function above
cols=pltcolor(x)

plt.scatter(x=x,y=y,s=500,c=cols) #Pass on the list created by the function here
plt.grid(True)
plt.show()

Coloring scatter plot as a function of x variable

How to check type of object in Python?

What type() means:

I think your question is a bit more general than I originally thought. type() with one argument returns the type or class of the object. So if you have a = 'abc' and use type(a) this returns str because the variable a is a string. If b = 10, type(b) returns int.

See also python documentation on type().


For comparisons:

If you want a comparison you could use: if type(v) == h5py.h5r.Reference (to check if it is a h5py.h5r.Reference instance).

But it is recommended that one uses if isinstance(v, h5py.h5r.Reference) but then also subclasses will evaluate to True.

If you want to print the class use print v.__class__.__name__.

More generally: You can compare if two instances have the same class by using type(v) is type(other_v) or isinstance(v, other_v.__class__).

Why should text files end with a newline?

Each line should be terminated in a newline character, including the last one. Some programs have problems processing the last line of a file if it isn't newline terminated.

GCC warns about it not because it can't process the file, but because it has to as part of the standard.

The C language standard says A source file that is not empty shall end in a new-line character, which shall not be immediately preceded by a backslash character.

Since this is a "shall" clause, we must emit a diagnostic message for a violation of this rule.

This is in section 2.1.1.2 of the ANSI C 1989 standard. Section 5.1.1.2 of the ISO C 1999 standard (and probably also the ISO C 1990 standard).

Reference: The GCC/GNU mail archive.

How to create .ipa file using Xcode?

Here is the steps I followed to export the .ipa

  • Validate the archive
  • Click on on distribute the app
  • Click the distribution method
  • Choose the export in the next screen (The screen shown only if the archive is validated)

How to resolve "must be an instance of string, string given" prior to PHP 7?

(originally posted by leepowers in his question)

The error message is confusing for one big reason:

Primitive type names are not reserved in PHP

The following are all valid class declarations:

class string { }
class int { }
class float { }
class double { }

My mistake was in thinking that the error message was referring solely to the string primitive type - the word 'instance' should have given me pause. An example to illustrate further:

class string { }
$n = 1234;
$s1 = (string)$n;
$s2 = new string();
$a = array('no', 'yes');
printf("\$s1 - primitive string? %s - string instance? %s\n",
        $a[is_string($s1)], $a[is_a($s1, 'string')]);
printf("\$s2 - primitive string? %s - string instance? %s\n",
        $a[is_string($s2)], $a[is_a($s2, 'string')]);

Output:

$s1 - primitive string? yes - string instance? no

$s2 - primitive string? no - string instance? yes

In PHP it's possible for a string to be a string except when it's actually a string. As with any language that uses implicit type conversion, context is everything.

How to get the filename without the extension from a path in Python?

In Python 3.4+ you can use the pathlib solution

from pathlib import Path

print(Path(your_path).resolve().stem)

Why use the params keyword?

Adding params keyword itself shows that you can pass multiple number of parameters while calling that method which is not possible without using it. To be more specific:

static public int addTwoEach(params int[] args)
{
    int sum = 0;

    foreach (var item in args)
    {
        sum += item + 2;
    }

    return sum;
}

When you will call above method you can call it by any of the following ways:

  1. addTwoEach()
  2. addTwoEach(1)
  3. addTwoEach(new int[]{ 1, 2, 3, 4 })

But when you will remove params keyword only third way of the above given ways will work fine. For 1st and 2nd case you will get an error.

NGINX - No input file specified. - php Fast/CGI

Resolving "No input file specified" error

If you are using nginx with php-cgi and have followed the standard procedure to set it up, you might often get the “No input file specified” error. This error basically occurs when the php-cgi daemon cannot find a .php file to execute using the SCRIPT_FILENAME parameter that was supplied to it. I’ll discuss about the common causes of the error and it’s solutions. Wrong path is sent to the php-cgi daemon

More often than not, a wrong path (SCRIPT_FILENAME) is sent to the fastCGI daemon. In many of the cases, this is due to a misconfiguration. Some of the setups I have seen are configured like this :

server {
    listen   [::]:80;
    server_name  example.com www.example.com;
    access_log  /var/www/logs/example.com.access.log;  

    location / {
        root   /var/www/example.com;
        index  index.html index.htm index.pl;
    }

    location /images {
        autoindex on;
    }

    location ~ \.php$ {
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  /var/www/example.com$fastcgi_script_name;
        include fastcgi_params;
    }
}

Now, there are many things wrong with this configuration. An obvious and glaring issue is the root directive in the location / block. When the root is defined inside the location block, it is available/defined for that block only. Here, the location /images block will not match for any request because it does not have any $document _root defined and we will have to redundantly define root again for it. Obviously, the root directive should be moved out of the location / block and defined in the server block. This way, the location blocks will inherit the value defined in the parental server block. Of course, if you want to define a different $document_root for a location, you can put a root directive in a location block.

Another issue is that the value of the fastCGI parameter SCRIPT_FILENAME is hard-coded. If we change the value of the root directive and move our files somewhere else in the directory chain, php-cgi will return a “No input file specified” error because will not be able to find the file in the hard-coded location which didn’t change when the $document_root was changed. So, we should set SCRIPT_FILENAME as below :

fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;

We should keep in mind that the root directive should be in the server block or else, only the $fastcgi_script_name will get passed as the SCRIPT_FILENAME and we will get the “No input file specified” error.

source(Resolving "No input file specified" error)

How do I assign a null value to a variable in PowerShell?

Use $dec = $null

From the documentation:

$null is an automatic variable that contains a NULL or empty value. You can use this variable to represent an absent or undefined value in commands and scripts.

PowerShell treats $null as an object with a value, that is, as an explicit placeholder, so you can use $null to represent an empty value in a series of values.

How to increment variable under DOS?

Indeed, set in DOS has no option to allow for arithmetic. You could do a giant lookup table, though:

if %COUNTER%==249 set COUNTER=250
...
if %COUNTER%==3 set COUNTER=4
if %COUNTER%==2 set COUNTER=3
if %COUNTER%==1 set COUNTER=2
if %COUNTER%==0 set COUNTER=1

Where do I find old versions of Android NDK?

http://dl.google.com/android/ndk/android-ndk-r9d-linux-x86_64.tar.bz2

I successfully opened gstreamer SDK tutorials in Eclipse.

All I needed is to use an older version of ndk. specificly 9d.

(10c and 10d does not work, 10b - works just for tutorial-1 )

9d does work for all tutorials ! and you can:

  1. Download it from: http://dl.google.com/android/ndk/android-ndk-r9d-linux-x86_64.tar.bz2

  2. Extract it.

  3. set it in eclipse->window->preferences->Android->NDK->NDK location.

  4. build - (ctrl+b).

Laravel - Pass more than one variable to view

Use compact

function view($view)
{
    $ms = Person::where('name', '=', 'Foo Bar')->first();

    $persons = Person::order_by('list_order', 'ASC')->get();
    return View::make('users', compact('ms','persons'));
}

Convert Object to JSON string

You can use the excellent jquery-Json plugin:

http://code.google.com/p/jquery-json/

Makes it easy to convert to and from Json objects.

How do I directly modify a Google Chrome Extension File? (.CRX)

Installed Chrome extension directories are listed below:

  1. Copy the folder of the extension you wish to modify. ( Named according to the extension ID, to find the ID of the extension, go to chrome://extensions/). Once copied, you have to remove the _metadata folder.

  2. From chrome://extensions in Developer mode select Load unpacked extension... and select your copied extension folder, if it contains a subfolder this is named by the version, select this version folder where there is a manifest file, this file is necessary for Chrome.

  3. Make your changes, then select reload and refresh the page for your extension to see your changes.


Chrome extension directories

Mac:

/Users/username/Library/Application Support/Google/Chrome/Default/Extensions

Windows 7:

C:\Users\username\AppData\Local\Google\Chrome\User Data\Default\Extensions

Windows XP:

C:\Documents and Settings\YourUserName\Local Settings\Application Data\Google\Chrome\User Data\Default

Ubuntu 14.04:

~/.config/google-chrome/Default/Extensions/

Beginner question: returning a boolean value from a function in Python

Ignoring the refactoring issues, you need to understand functions and return values. You don't need a global at all. Ever. You can do this:

def rps():
    # Code to determine if player wins
    if player_wins:
        return True

    return False

Then, just assign a value to the variable outside this function like so:

player_wins = rps()

It will be assigned the return value (either True or False) of the function you just called.


After the comments, I decided to add that idiomatically, this would be better expressed thus:

 def rps(): 
     # Code to determine if player wins, assigning a boolean value (True or False)
     # to the variable player_wins.

     return player_wins

 pw = rps()

This assigns the boolean value of player_wins (inside the function) to the pw variable outside the function.

How to Resize image in Swift?

For Swift 4.0 and iOS 10

    extension UIImage {
        func resizeImage(_ dimension: CGFloat, opaque: Bool, contentMode: UIViewContentMode = .scaleAspectFit) -> UIImage {
            var width: CGFloat
            var height: CGFloat
            var newImage: UIImage

            let size = self.size
            let aspectRatio =  size.width/size.height

            switch contentMode {
                case .scaleAspectFit:
                    if aspectRatio > 1 {                            // Landscape image
                        width = dimension
                        height = dimension / aspectRatio
                    } else {                                        // Portrait image
                        height = dimension
                        width = dimension * aspectRatio
                    }

            default:
                fatalError("UIIMage.resizeToFit(): FATAL: Unimplemented ContentMode")
            }

            if #available(iOS 10.0, *) {
                let renderFormat = UIGraphicsImageRendererFormat.default()
                renderFormat.opaque = opaque
                let renderer = UIGraphicsImageRenderer(size: CGSize(width: width, height: height), format: renderFormat)
                newImage = renderer.image {
                    (context) in
                    self.draw(in: CGRect(x: 0, y: 0, width: width, height: height))
                }
            } else {
                UIGraphicsBeginImageContextWithOptions(CGSize(width: width, height: height), opaque, 0)
                    self.draw(in: CGRect(x: 0, y: 0, width: width, height: height))
                    newImage = UIGraphicsGetImageFromCurrentImageContext()!
                UIGraphicsEndImageContext()
            }

            return newImage
        }
    }

How to get the first and last date of the current year?

To get the first and the last day of the year, one can use the CONCAT function. The resulting value may be cast to any type.

CONCAT(YEAR(Getdate()),'-01-01') FirstOfYear,
CONCAT(YEAR(GETDATE()),'-12-31') LastOfYear

Does Index of Array Exist

You can rather use a List, so you can check the existence.

List<int> l = new List<int>();
l.Add(45);
...
...

if (l.Count == 25) {
  doStuff();
}
int num = 45;
if (l.Contains(num)) {
  doMoreStuff();
}

How do you implement a Stack and a Queue in JavaScript?

Here is a fairly simple queue implementation with two aims:

  • Unlike array.shift(), you know this dequeue method takes constant time (O(1)).
  • To improve speed, this approach uses many fewer allocations than the linked-list approach.

The stack implementation shares the second aim only.

// Queue
function Queue() {
        this.q = new Array(5);
        this.first = 0;
        this.size = 0;
}
Queue.prototype.enqueue = function(a) {
        var other;
        if (this.size == this.q.length) {
                other = new Array(this.size*2);
                for (var i = 0; i < this.size; i++) {
                        other[i] = this.q[(this.first+i)%this.size];
                }
                this.first = 0;
                this.q = other;
        }
        this.q[(this.first+this.size)%this.q.length] = a;
        this.size++;
};
Queue.prototype.dequeue = function() {
        if (this.size == 0) return undefined;
        this.size--;
        var ret = this.q[this.first];
        this.first = (this.first+1)%this.q.length;
        return ret;
};
Queue.prototype.peek = function() { return this.size > 0 ? this.q[this.first] : undefined; };
Queue.prototype.isEmpty = function() { return this.size == 0; };

// Stack
function Stack() {
        this.s = new Array(5);
        this.size = 0;
}
Stack.prototype.push = function(a) {
        var other;
    if (this.size == this.s.length) {
            other = new Array(this.s.length*2);
            for (var i = 0; i < this.s.length; i++) other[i] = this.s[i];
            this.s = other;
    }
    this.s[this.size++] = a;
};
Stack.prototype.pop = function() {
        if (this.size == 0) return undefined;
        return this.s[--this.size];
};
Stack.prototype.peek = function() { return this.size > 0 ? this.s[this.size-1] : undefined; };

SQL Row_Number() function in Where Clause

based on OP's answer to question:

Please see this link. Its having a different solution, which looks working for the person who asked the question. I'm trying to figure out a solution like this.

Paginated query using sorting on different columns using ROW_NUMBER() OVER () in SQL Server 2005

~Joseph

"method 1" is like the OP's query from the linked question, and "method 2" is like the query from the selected answer. You had to look at the code linked in this answer to see what was really going on, since the code in the selected answer was modified to make it work. Try this:

DECLARE @YourTable table (RowID int not null primary key identity, Value1 int, Value2 int, value3 int)
SET NOCOUNT ON
INSERT INTO @YourTable VALUES (1,1,1)
INSERT INTO @YourTable VALUES (1,1,2)
INSERT INTO @YourTable VALUES (1,1,3)
INSERT INTO @YourTable VALUES (1,2,1)
INSERT INTO @YourTable VALUES (1,2,2)
INSERT INTO @YourTable VALUES (1,2,3)
INSERT INTO @YourTable VALUES (1,3,1)
INSERT INTO @YourTable VALUES (1,3,2)
INSERT INTO @YourTable VALUES (1,3,3)
INSERT INTO @YourTable VALUES (2,1,1)
INSERT INTO @YourTable VALUES (2,1,2)
INSERT INTO @YourTable VALUES (2,1,3)
INSERT INTO @YourTable VALUES (2,2,1)
INSERT INTO @YourTable VALUES (2,2,2)
INSERT INTO @YourTable VALUES (2,2,3)
INSERT INTO @YourTable VALUES (2,3,1)
INSERT INTO @YourTable VALUES (2,3,2)
INSERT INTO @YourTable VALUES (2,3,3)
INSERT INTO @YourTable VALUES (3,1,1)
INSERT INTO @YourTable VALUES (3,1,2)
INSERT INTO @YourTable VALUES (3,1,3)
INSERT INTO @YourTable VALUES (3,2,1)
INSERT INTO @YourTable VALUES (3,2,2)
INSERT INTO @YourTable VALUES (3,2,3)
INSERT INTO @YourTable VALUES (3,3,1)
INSERT INTO @YourTable VALUES (3,3,2)
INSERT INTO @YourTable VALUES (3,3,3)
SET NOCOUNT OFF

DECLARE @PageNumber     int
DECLARE @PageSize       int
DECLARE @SortBy         int

SET @PageNumber=3
SET @PageSize=5
SET @SortBy=1


--SELECT * FROM @YourTable

--Method 1
;WITH PaginatedYourTable AS (
SELECT
    RowID,Value1,Value2,Value3
        ,CASE @SortBy
             WHEN  1 THEN ROW_NUMBER() OVER (ORDER BY Value1 ASC)
             WHEN  2 THEN ROW_NUMBER() OVER (ORDER BY Value2 ASC)
             WHEN  3 THEN ROW_NUMBER() OVER (ORDER BY Value3 ASC)
             WHEN -1 THEN ROW_NUMBER() OVER (ORDER BY Value1 DESC)
             WHEN -2 THEN ROW_NUMBER() OVER (ORDER BY Value2 DESC)
             WHEN -3 THEN ROW_NUMBER() OVER (ORDER BY Value3 DESC)
         END AS RowNumber
    FROM @YourTable
    --WHERE
)
SELECT
    RowID,Value1,Value2,Value3,RowNumber
        ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy
    FROM PaginatedYourTable
    WHERE RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1
    ORDER BY RowNumber



--------------------------------------------
--Method 2
;WITH PaginatedYourTable AS (
SELECT
    RowID,Value1,Value2,Value3
        ,ROW_NUMBER() OVER
         (
             ORDER BY
                 CASE @SortBy
                     WHEN  1 THEN Value1
                     WHEN  2 THEN Value2
                     WHEN  3 THEN Value3
                 END ASC
                ,CASE @SortBy
                     WHEN -1 THEN Value1
                     WHEN -2 THEN Value2
                     WHEN -3 THEN Value3
                 END DESC
         ) RowNumber
    FROM @YourTable
    --WHERE  more conditions here
)
SELECT
    RowID,Value1,Value2,Value3,RowNumber
        ,@PageNumber AS PageNumber, @PageSize AS PageSize, @SortBy AS SortBy
    FROM PaginatedYourTable
    WHERE 
        RowNumber>=(@PageNumber-1)*@PageSize AND RowNumber<=(@PageNumber*@PageSize)-1
        --AND more conditions here
    ORDER BY
        CASE @SortBy
            WHEN  1 THEN Value1
            WHEN  2 THEN Value2
            WHEN  3 THEN Value3
        END ASC
       ,CASE @SortBy
            WHEN -1 THEN Value1
            WHEN -2 THEN Value2
            WHEN -3 THEN Value3
        END DESC

OUTPUT:

RowID  Value1 Value2 Value3 RowNumber  PageNumber  PageSize    SortBy
------ ------ ------ ------ ---------- ----------- ----------- -----------
10     2      1      1      10         3           5           1
11     2      1      2      11         3           5           1
12     2      1      3      12         3           5           1
13     2      2      1      13         3           5           1
14     2      2      2      14         3           5           1

(5 row(s) affected

RowID  Value1 Value2 Value3 RowNumber  PageNumber  PageSize    SortBy
------ ------ ------ ------ ---------- ----------- ----------- -----------
10     2      1      1      10         3           5           1
11     2      1      2      11         3           5           1
12     2      1      3      12         3           5           1
13     2      2      1      13         3           5           1
14     2      2      2      14         3           5           1

(5 row(s) affected)

How to call gesture tap on UIView programmatically in swift

This is how it works in Swift 3:

@IBOutlet var myView: UIView!
override func viewDidLoad() {
    super.viewDidLoad()

    let tap = UITapGestureRecognizer(target: self, action:#selector(handleTap))

    myView.addGestureRecognizer(tap)
}

func handleTap() {
    print("tapped")
}

Getting reference to the top-most view/window in iOS application

If your application only works in portrait orientation, this is enough:

[[[UIApplication sharedApplication] keyWindow] addSubview:yourView]

And your view will not be shown over keyboard and status bar.

If you want to get a topmost view that over keyboard or status bar, or you want the topmost view can rotate correctly with devices, please try this framework:

https://github.com/HarrisonXi/TopmostView

It supports iOS7/8/9.

"Initializing" variables in python?

I know you have already accepted another answer, but I think the broader issue needs to addressed - programming style that is suitable to the current language.

Yes, 'initialization' isn't needed in Python, but what you are doing isn't initialization. It is just an incomplete and erroneous imitation of initialization as practiced in other languages. The important thing about initialization in static typed languages is that you specify the nature of the variables.

In Python, as in other languages, you do need to give variables values before you use them. But giving them values at the start of the function isn't important, and even wrong if the values you give have nothing to do with values they receive later. That isn't 'initialization', it's 'reuse'.

I'll make some notes and corrections to your code:

def main():
   # doc to define the function
   # proper Python indentation
   # document significant variables, especially inputs and outputs
   # grade_1, grade_2, grade_3, average - id these
   # year - id this
   # fName, lName, ID, converted_ID 

   infile = open("studentinfo.txt", "r") 
   # you didn't 'intialize' this variable

   data = infile.read()  
   # nor this  

   fName, lName, ID, year = data.split(",")
   # this will produce an error if the file does not have the right number of strings
   # 'year' is now a string, even though you 'initialized' it as 0

   year = int(year)
   # now 'year' is an integer
   # a language that requires initialization would have raised an error
   # over this switch in type of this variable.

   # Prompt the user for three test scores
   grades = eval(input("Enter the three test scores separated by a comma: "))
   # 'eval' ouch!
   # you could have handled the input just like you did the file input.

   grade_1, grade_2, grade_3 = grades   
   # this would work only if the user gave you an 'iterable' with 3 values
   # eval() doesn't ensure that it is an iterable
   # and it does not ensure that the values are numbers. 
   # What would happen with this user input: "'one','two','three',4"?

   # Create a username 
   uName = (lName[:4] + fName[:2] + str(year)).lower()

   converted_id = ID[:3] + "-" + ID[3:5] + "-" + ID[5:]
   # earlier you 'initialized' converted_ID
   # initialization in a static typed language would have caught this typo
   # pseudo-initialization in Python does not catch typos
   ....

How do I get console input in javascript?

You can try something like process.argv, that is if you are using node.js to run the program.
console.log(process.argv) => Would print an array containing

[                                                                                                                                                                                          
  '/usr/bin/node',                                                                                                                                                                         
  '/home/user/path/filename.js',                                                                                                                                            
  'your_input'                                                                                                                                                                                   
]

You get the user provided input via array index, i.e., console.log(process.argv[3]) This should provide you with the input which you can store.


Example:

var somevariable = process.argv[3]; // input one
var somevariable2 = process.argv[4]; // input two

console.log(somevariable);
console.log(somevariable2);

If you are building a command-line program then the npm package yargs would be really helpful.

Twitter Bootstrap Datepicker within modal window

This solutions worked perfectly for me to render the datepicker on top of bootstrap modal.

http://jsfiddle.net/cmpgtuwy/654/

HTML

<br/>
<div class="wrapper">
Some content goes here<br />
Some more content.
<div class="row">
<div class="col-xs-4">

<!-- padding for jsfiddle -->
<div class="input-group date" id="dtp">
<input type="text" class="form-control" />  
<span class="input-group-addon">
  <span class="glyphicon-calendar glyphicon"></span>
</span>
</div>
</div>
</div>
</div>

Javascript

$('#dtp').datetimepicker({
format: 'MMM D, YYYY',
widgetParent: 'body'});


$('#dtp').on('dp.show', function() {
      var datepicker = $('body').find('.bootstrap-datetimepicker-widget:last');
      if (datepicker.hasClass('bottom')) {
        var top = $(this).offset().top + $(this).outerHeight();
        var left = $(this).offset().left;
        datepicker.css({
          'top': top + 'px',
          'bottom': 'auto',
          'left': left + 'px'
        });
      }
      else if (datepicker.hasClass('top')) {
        var top = $(this).offset().top - datepicker.outerHeight();
        var left = $(this).offset().left;
        datepicker.css({
          'top': top + 'px',
          'bottom': 'auto',
          'left': left + 'px'
        });
      }
    });

CSS

.wrapper {
height: 100px;
overflow: auto;}
body {
position: relative;
}

How to set height property for SPAN

Another option of course is to use Javascript (Jquery here):

$('.box1,.box2').each(function(){
    $(this).height($(this).parent().height());
})

Changing datagridview cell color dynamically

Thanks it working

here i am done with this by qty field is zero means it shown that cells are in red color

        int count = 0;

        foreach (DataGridViewRow row in ItemDg.Rows)
        {
            int qtyEntered = Convert.ToInt16(row.Cells[1].Value);
            if (qtyEntered <= 0)
            {
                ItemDg[0, count].Style.BackColor = Color.Red;//to color the row
                ItemDg[1, count].Style.BackColor = Color.Red;

                ItemDg[0, count].ReadOnly = true;//qty should not be enter for 0 inventory                       
            }
            ItemDg[0, count].Value = "0";//assign a default value to quantity enter
            count++;
        }

    }

SQL - How to select a row having a column with max value

Technically, this is the same answer as @Sujee. It also depends on your version of Oracle as to whether it works. (I think this syntax was introduced in Oracle 12??)

SELECT *
FROM   table
ORDER BY value DESC, date_column ASC
FETCH  first 1 rows only;

As I say, if you look under the bonnet, I think this code is unpacked internally by the Oracle Optimizer to read like @Sujee's. However, I'm a sucker for pretty coding, and nesting select statements without a good reason does not qualify as beautiful!! :-P

How to remove numbers from string using Regex.Replace?

text= re.sub('[0-9\n]',' ',text)

install regex in python which is re then do the following code.

Changing Background Image with CSS3 Animations

I needed to do the same thing as you and landed on your question. I ended up taking finding about the steps function which I read about from here.

JSFiddle of my solution in action (Note it currently works in Firefox, I'll let you add the crossbrowser lines, trying to keep the solution clean of clutter)

First I created a sprite sheet that had two frames. Then I created the div and put that as the background, but my div is only the size of my sprite (100px).

<div id="cyclist"></div>

#cyclist {
    animation: cyclist 1s infinite steps(2);
    display: block;
    width: 100px;
    height: 100px;
    background-image: url('../images/cyclist-test.png');
    background-repeat: no-repeat;
    background-position: top left;
  }

The animation is set to have 2 steps and have the whole process take 1 second.

@keyframes cyclist {
  0% {
    background-position: 0 0; 
   }
  100% { 
    background-position: 0 -202px; //this should be cleaned up, my sprite sheet is 202px by accident, it should be 200px
   }
}

Thiago above mentioned the steps function but I thought I'd elaborate more on it. Pretty simple and awesome stuff.

Automatically run %matplotlib inline in IPython Notebook

The configuration way

IPython has profiles for configuration, located at ~/.ipython/profile_*. The default profile is called profile_default. Within this folder there are two primary configuration files:

  • ipython_config.py
  • ipython_kernel_config.py

Add the inline option for matplotlib to ipython_kernel_config.py:

c = get_config()
# ... Any other configurables you want to set
c.InteractiveShellApp.matplotlib = "inline"

matplotlib vs. pylab

Usage of %pylab to get inline plotting is discouraged.

It introduces all sorts of gunk into your namespace that you just don't need.

%matplotlib on the other hand enables inline plotting without injecting your namespace. You'll need to do explicit calls to get matplotlib and numpy imported.

import matplotlib.pyplot as plt
import numpy as np

The small price of typing out your imports explicitly should be completely overcome by the fact that you now have reproducible code.

Passing arguments to JavaScript function from code-behind

I think you want to execute the javascript serverside and not in the browser after post-back, right?

That's not possible as far as I know

If you just want to get it execute after postback, you can do something like this:

this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "xx", "<script>test("+x+","+y+");</script>");

CSS: how to position element in lower right?

Set the CSS position: relative; on the box. This causes all absolute positions of objects inside to be relative to the corners of that box. Then set the following CSS on the "Bet 5 days ago" line:

position: absolute;
bottom: 0;
right: 0;

If you need to space the text farther away from the edge, you could change 0 to 2px or similar.

String.Replace(char, char) method in C#

string temp = mystring.Replace("\n", " ");

xpath find if node exists

I work in Ruby and using Nokogiri I fetch the element and look to see if the result is nil.

require 'nokogiri'

url = "http://somthing.com/resource"

resp = Nokogiri::XML(open(url))

first_name = resp.xpath("/movies/actors/actor[1]/first-name")

puts "first-name not found" if first_name.nil?

Reordering Chart Data Series

This function gets the series names, puts them into an array, sorts the array and based on that defines the plotting order which will give the desired output.

Function Increasing_Legend_Sort(mychart As Chart)


    Dim Arr()
    ReDim Arr(1 To mychart.FullSeriesCollection.Count)

        'Assigning Series names to an array
        For i = LBound(Arr) To UBound(Arr)
        Arr(i) = mychart.FullSeriesCollection(i).Name
        Next i

        'Bubble-Sort (Sort the array in increasing order)
        For r1 = LBound(Arr) To UBound(Arr)
            rval = Arr(r1)
                For r2 = LBound(Arr) To UBound(Arr)
                    If Arr(r2) > rval Then 'Change ">" to "<" to make it decreasing
                        Arr(r1) = Arr(r2)
                        Arr(r2) = rval
                        rval = Arr(r1)
                    End If
                Next r2
        Next r1

    'Defining the PlotOrder
    For i = LBound(Arr) To UBound(Arr)
    mychart.FullSeriesCollection(Arr(i)).PlotOrder = i
    Next i

End Function

Phone: numeric keyboard for text input

I think type="number" is the best for semantic web page. If you just want to change the keyboard, you can use type="number" or type="tel". In both cases, iPhone doesn't restrict user input. User can still type in (or paste in) any characters he/she wants. The only change is the keyboard shown to the user. If you want any restriction beyond this, you need to use JavaScript.

Importing CSV File to Google Maps

GPS Visualizer has an interface by which you can cut and paste a CSV file and convert it to kml:

http://www.gpsvisualizer.com/map_input?form=googleearth

Then use Google Earth. If you don't have Google Earth and want to display it online I found another nifty service that will plot kml files online:

http://display-kml.appspot.com/