Programs & Examples On #Lock in

Is Android using NTP to sync time?

I have a Samsung Galaxy Tab 2 7.0 with Android 4.1.1. Apparently it does NOT sync to ntp. I loaded an app that says my tablet is 20 seconds off of ntp, but it can't set it unless I root the device.

SQL query to get the deadlocks in SQL SERVER 2008

You can use a deadlock graph and gather the information you require from the log file.

The only other way I could suggest is digging through the information by using EXEC SP_LOCK (Soon to be deprecated), EXEC SP_WHO2 or the sys.dm_tran_locks table.

SELECT  L.request_session_id AS SPID, 
    DB_NAME(L.resource_database_id) AS DatabaseName,
    O.Name AS LockedObjectName, 
    P.object_id AS LockedObjectId, 
    L.resource_type AS LockedResource, 
    L.request_mode AS LockType,
    ST.text AS SqlStatementText,        
    ES.login_name AS LoginName,
    ES.host_name AS HostName,
    TST.is_user_transaction as IsUserTransaction,
    AT.name as TransactionName,
    CN.auth_scheme as AuthenticationMethod
FROM    sys.dm_tran_locks L
    JOIN sys.partitions P ON P.hobt_id = L.resource_associated_entity_id
    JOIN sys.objects O ON O.object_id = P.object_id
    JOIN sys.dm_exec_sessions ES ON ES.session_id = L.request_session_id
    JOIN sys.dm_tran_session_transactions TST ON ES.session_id = TST.session_id
    JOIN sys.dm_tran_active_transactions AT ON TST.transaction_id = AT.transaction_id
    JOIN sys.dm_exec_connections CN ON CN.session_id = ES.session_id
    CROSS APPLY sys.dm_exec_sql_text(CN.most_recent_sql_handle) AS ST
WHERE   resource_database_id = db_id()
ORDER BY L.request_session_id

http://www.sqlmag.com/article/sql-server-profiler/gathering-deadlock-information-with-deadlock-graph

http://weblogs.sqlteam.com/mladenp/archive/2008/04/29/SQL-Server-2005-Get-full-information-about-transaction-locks.aspx

How to add link to flash banner

@Michiel is correct to create a button but the code for ActionScript 3 it is a little different - where movieClipName is the name of your 'button'.

movieClipName.addEventListener(MouseEvent.CLICK, callLink);
function callLink:void {
  var url:String = "http://site";
  var request:URLRequest = new URLRequest(url);
  try {
    navigateToURL(request, '_blank');
  } catch (e:Error) {
    trace("Error occurred!");
  }
}

source: http://scriptplayground.com/tutorials/as/getURL-in-Actionscript-3/

Variables within app.config/web.config

A slightly more complicated, but far more flexible, alternative is to create a class that represents a configuration section. In your app.config / web.config file, you can have this:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <!-- This section must be the first section within the <configuration> node -->
    <configSections>
        <section name="DirectoryInfo" type="MyProjectNamespace.DirectoryInfoConfigSection, MyProjectAssemblyName" />
    </configSections>

    <DirectoryInfo>
        <Directory MyBaseDir="C:\MyBase" Dir1="Dir1" Dir2="Dir2" />
    </DirectoryInfo>
</configuration>

Then, in your .NET code (I'll use C# in my example), you can create two classes like this:

using System;
using System.Configuration;

namespace MyProjectNamespace {

    public class DirectoryInfoConfigSection : ConfigurationSection {

        [ConfigurationProperty("Directory")]
        public DirectoryConfigElement Directory {
            get {
                return (DirectoryConfigElement)base["Directory"];
            }
    }

    public class DirectoryConfigElement : ConfigurationElement {

        [ConfigurationProperty("MyBaseDir")]
        public String BaseDirectory {
            get {
                return (String)base["MyBaseDir"];
            }
        }

        [ConfigurationProperty("Dir1")]
        public String Directory1 {
            get {
                return (String)base["Dir1"];
            }
        }

        [ConfigurationProperty("Dir2")]
        public String Directory2 {
            get {
                return (String)base["Dir2"];
            }
        }
        // You can make custom properties to combine your directory names.
        public String Directory1Resolved {
            get {
                return System.IO.Path.Combine(BaseDirectory, Directory1);
            }
        }
    }
}

Finally, in your program code, you can access your app.config variables, using your new classes, in this manner:

DirectoryInfoConfigSection config =
  (DirectoryInfoConfigSection)ConfigurationManager.GetSection("DirectoryInfo");
String dir1Path = config.Directory.Directory1Resolved;  // This value will equal "C:\MyBase\Dir1"

Load properties file in JAR?

The problem is that you are using getSystemResourceAsStream. Use simply getResourceAsStream. System resources load from the system classloader, which is almost certainly not the class loader that your jar is loaded into when run as a webapp.

It works in Eclipse because when launching an application, the system classloader is configured with your jar as part of its classpath. (E.g. java -jar my.jar will load my.jar in the system class loader.) This is not the case with web applications - application servers use complex class loading to isolate webapplications from each other and from the internals of the application server. For example, see the tomcat classloader how-to, and the diagram of the classloader hierarchy used.

EDIT: Normally, you would call getClass().getResourceAsStream() to retrieve a resource in the classpath, but as you are fetching the resource in a static initializer, you will need to explicitly name a class that is in the classloader you want to load from. The simplest approach is to use the class containing the static initializer, e.g.

[public] class MyClass {
  static
  {
    ...
    props.load(MyClass.class.getResourceAsStream("/someProps.properties"));
  }
}

ssh_exchange_identification: Connection closed by remote host under Git bash

To solve this edit /etc/ssh/ssh_config and comment the following line 1

ProxyCommand /usr/bin/sss_ssh_knownhostsproxy -p %p %h

https://www.evilbox.ro/linux/solve-ssh_exchange_identification-connection-closed-by-remote-host/ for reference

Constructors in Go

In Go, a constructor can be implemented using a function that returns a pointer to a modified structure.

type Colors struct {
    R   byte
    G   byte
    B   byte
}

// Constructor
func NewColors (r, g, b byte) *Colors {
    return &Color{R:r, G:g, B:b}
}

For weak dependencies and better abstraction, the constructor does not return a pointer to a structure, but an interface that this structure implements.

type Painter interface {
    paintMethod1() byte
    paintMethod2(byte) byte
}

type Colors struct {
    R byte
    G byte
    B byte
}

// Constructor return intreface
func NewColors(r, g, b byte) Painter {
    return &Color{R: r, G: g, B: b}
}

func (c *Colors) paintMethod1() byte {
    return c.R
}

func (c *Colors) paintMethod2(b byte) byte {
    return c.B = b
}

Pandas: how to change all the values of a column?

You can do a column transformation by using apply

Define a clean function to remove the dollar and commas and convert your data to float.

def clean(x):
    x = x.replace("$", "").replace(",", "").replace(" ", "")
    return float(x)

Next, call it on your column like this.

data['Revenue'] = data['Revenue'].apply(clean)

Access multiple viewchildren using @viewchild

Use the @ViewChildren decorator combined with QueryList. Both of these are from "@angular/core"

@ViewChildren(CustomComponent) customComponentChildren: QueryList<CustomComponent>;

Doing something with each child looks like: this.customComponentChildren.forEach((child) => { child.stuff = 'y' })

There is further documentation to be had at angular.io, specifically: https://angular.io/docs/ts/latest/cookbook/component-communication.html#!#sts=Parent%20calls%20a%20ViewChild

Connection reset by peer: mod_fcgid: error reading data from FastCGI server

Check /var/lib/php/session and its permissions. This dir should be writable by user so the session can be stored

Is there a way to break a list into columns?

This answer doesn't necessarily scale but only requires minor adjustments as the list grows. Semantically it might seem a little counter-intuitive since it is two lists, but aside from that it'll look the way you want in any browser ever made.

_x000D_
_x000D_
ul {_x000D_
  float: left;_x000D_
}_x000D_
_x000D_
ul > li {_x000D_
  width: 6em;_x000D_
}
_x000D_
<!-- Column 1 -->_x000D_
<ul>_x000D_
  <li>Item 1</li>_x000D_
  <li>Item 2</li>_x000D_
  <li>Item 3</li>_x000D_
</ul>_x000D_
<!-- Column 2 -->_x000D_
<ul>_x000D_
  <li>Item 4</li>_x000D_
  <li>Item 5</li>_x000D_
  <li>Item 6</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

XPath to get all child nodes (elements, comments, and text) without parent

From the documentation of XPath ( http://www.w3.org/TR/xpath/#location-paths ):

child::* selects all element children of the context node

child::text() selects all text node children of the context node

child::node() selects all the children of the context node, whatever their node type

So I guess your answer is:

$doc/PRESENTEDIN/X/child::node()

And if you want a flatten array of all nested nodes:

$doc/PRESENTEDIN/X/descendant::node()

Static variables in JavaScript

If you want to use prototype then there is a way

var p = function Person() {
    this.x = 10;
    this.y = 20;
}
p.prototype.counter = 0;
var person1 = new p();
person1.prototype = p.prototype;
console.log(person1.counter);
person1.prototype.counter++;
var person2 = new p();
person2.prototype = p.prototype;
console.log(person2.counter);
console.log(person1.counter);

Doing this you will be able to access the counter variable from any instance and any change in the property will be immediately reflected!!

Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister

In my case the problem was because of conflicting Jars.

Here is the full list of jars which is working absolutely fine for me.

antlr-2.7.7.jar
byte-buddy-1.8.12.jar
c3p0-0.9.5.2.jar
classmate-1.3.4.jar
dom4j-1.6.1.jar
geolatte-geom-1.3.0.jar
hibernate-c3p0-5.3.1.Final.jar
hibernate-commons-annotations-5.0.3.Final.jar
hibernate-core-5.3.1.Final.jar
hibernate-envers-5.3.1.Final.jar
hibernate-jpamodelgen-5.3.1.Final.jar
hibernate-osgi-5.3.1.Final.jar
hibernate-proxool-5.3.1.Final.jar
hibernate-spatial-5.3.1.Final.jar
jandex-2.0.3.Final.jar
javassist-3.22.0-GA.jar
javax.interceptor-api-1.2.jar
javax.persistence-api-2.2.jar
jboss-logging-3.3.2.Final.jar
jboss-transaction-api_1.2_spec-1.1.1.Final.jar
jts-core-1.14.0.jar
mchange-commons-java-0.2.11.jar
mysql-connector-java-5.1.21.jar
org.osgi.compendium-4.3.1.jar
org.osgi.core-4.3.1.jar
postgresql-42.2.2.jar
proxool-0.8.3.jar
slf4j-api-1.6.1.jar

Need table of key codes for android and presenter

Complete list of key codes

Some of the other lists here are incomplete. The complete list can be found in the KeyEvent source code or documentation. The source code is ordered by integer value so I will use that here.

(Repetitive text removed to save space, all key codes are public static final int.)

/** Unknown key code. */
KEYCODE_UNKNOWN = 0;
/** Soft Left key.
 * Usually situated below the display on phones and used as a multi-function
 * feature key for selecting a software defined function shown on the bottom left
 * of the display. */
KEYCODE_SOFT_LEFT = 1;
/** Soft Right key.
 * Usually situated below the display on phones and used as a multi-function
 * feature key for selecting a software defined function shown on the bottom right
 * of the display. */
KEYCODE_SOFT_RIGHT = 2;
/** Home key.
 * This key is handled by the framework and is never delivered to applications. */
KEYCODE_HOME = 3;
/** Back key. */
KEYCODE_BACK = 4;
/** Call key. */
KEYCODE_CALL = 5;
/** End Call key. */
KEYCODE_ENDCALL = 6;
/** '0' key. */
KEYCODE_0 = 7;
/** '1' key. */
KEYCODE_1 = 8;
/** '2' key. */
KEYCODE_2 = 9;
/** '3' key. */
KEYCODE_3 = 10;
/** '4' key. */
KEYCODE_4 = 11;
/** '5' key. */
KEYCODE_5 = 12;
/** '6' key. */
KEYCODE_6 = 13;
/** '7' key. */
KEYCODE_7 = 14;
/** '8' key. */
KEYCODE_8 = 15;
/** '9' key. */
KEYCODE_9 = 16;
/** '*' key. */
KEYCODE_STAR = 17;
/** '#' key. */
KEYCODE_POUND = 18;
/** Directional Pad Up key.
 * May also be synthesized from trackball motions. */
KEYCODE_DPAD_UP = 19;
/** Directional Pad Down key.
 * May also be synthesized from trackball motions. */
KEYCODE_DPAD_DOWN = 20;
/** Directional Pad Left key.
 * May also be synthesized from trackball motions. */
KEYCODE_DPAD_LEFT = 21;
/** Directional Pad Right key.
 * May also be synthesized from trackball motions. */
KEYCODE_DPAD_RIGHT = 22;
/** Directional Pad Center key.
 * May also be synthesized from trackball motions. */
KEYCODE_DPAD_CENTER = 23;
/** Volume Up key.
 * Adjusts the speaker volume up. */
KEYCODE_VOLUME_UP = 24;
/** Volume Down key.
 * Adjusts the speaker volume down. */
KEYCODE_VOLUME_DOWN = 25;
/** Power key. */
KEYCODE_POWER = 26;
/** Camera key.
 * Used to launch a camera application or take pictures. */
KEYCODE_CAMERA = 27;
/** Clear key. */
KEYCODE_CLEAR = 28;
/** 'A' key. */
KEYCODE_A = 29;
/** 'B' key. */
KEYCODE_B = 30;
/** 'C' key. */
KEYCODE_C = 31;
/** 'D' key. */
KEYCODE_D = 32;
/** 'E' key. */
KEYCODE_E = 33;
/** 'F' key. */
KEYCODE_F = 34;
/** 'G' key. */
KEYCODE_G = 35;
/** 'H' key. */
KEYCODE_H = 36;
/** 'I' key. */
KEYCODE_I = 37;
/** 'J' key. */
KEYCODE_J = 38;
/** 'K' key. */
KEYCODE_K = 39;
/** 'L' key. */
KEYCODE_L = 40;
/** 'M' key. */
KEYCODE_M = 41;
/** 'N' key. */
KEYCODE_N = 42;
/** 'O' key. */
KEYCODE_O = 43;
/** 'P' key. */
KEYCODE_P = 44;
/** 'Q' key. */
KEYCODE_Q = 45;
/** 'R' key. */
KEYCODE_R = 46;
/** 'S' key. */
KEYCODE_S = 47;
/** 'T' key. */
KEYCODE_T = 48;
/** 'U' key. */
KEYCODE_U = 49;
/** 'V' key. */
KEYCODE_V = 50;
/** 'W' key. */
KEYCODE_W = 51;
/** 'X' key. */
KEYCODE_X = 52;
/** 'Y' key. */
KEYCODE_Y = 53;
/** 'Z' key. */
KEYCODE_Z = 54;
/** ',' key. */
KEYCODE_COMMA = 55;
/** '.' key. */
KEYCODE_PERIOD = 56;
/** Left Alt modifier key. */
KEYCODE_ALT_LEFT = 57;
/** Right Alt modifier key. */
KEYCODE_ALT_RIGHT = 58;
/** Left Shift modifier key. */
KEYCODE_SHIFT_LEFT = 59;
/** Right Shift modifier key. */
KEYCODE_SHIFT_RIGHT = 60;
/** Tab key. */
KEYCODE_TAB = 61;
/** Space key. */
KEYCODE_SPACE = 62;
/** Symbol modifier key.
 * Used to enter alternate symbols. */
KEYCODE_SYM = 63;
/** Explorer special function key.
 * Used to launch a browser application. */
KEYCODE_EXPLORER = 64;
/** Envelope special function key.
 * Used to launch a mail application. */
KEYCODE_ENVELOPE = 65;
/** Enter key. */
KEYCODE_ENTER = 66;
/** Backspace key.
 * Deletes characters before the insertion point, unlike {@link #KEYCODE_FORWARD_DEL}. */
KEYCODE_DEL = 67;
/** '`' (backtick) key. */
KEYCODE_GRAVE = 68;
/** '-'. */
KEYCODE_MINUS = 69;
/** '=' key. */
KEYCODE_EQUALS = 70;
/** '[' key. */
KEYCODE_LEFT_BRACKET = 71;
/** ']' key. */
KEYCODE_RIGHT_BRACKET = 72;
/** '\' key. */
KEYCODE_BACKSLASH = 73;
/** ';' key. */
KEYCODE_SEMICOLON = 74;
/** ''' (apostrophe) key. */
KEYCODE_APOSTROPHE = 75;
/** '/' key. */
KEYCODE_SLASH = 76;
/** '@' key. */
KEYCODE_AT = 77;
/** Number modifier key.
 * Used to enter numeric symbols.
 * This key is not Num Lock; it is more like {@link #KEYCODE_ALT_LEFT} and is
 * interpreted as an ALT key by {@link android.text.method.MetaKeyKeyListener}. */
KEYCODE_NUM = 78;
/** Headset Hook key.
 * Used to hang up calls and stop media. */
KEYCODE_HEADSETHOOK = 79;
/** Camera Focus key.
 * Used to focus the camera. */
KEYCODE_FOCUS = 80; // *Camera* focus
/** '+' key. */
KEYCODE_PLUS = 81;
/** Menu key. */
KEYCODE_MENU = 82;
/** Notification key. */
KEYCODE_NOTIFICATION = 83;
/** Search key. */
KEYCODE_SEARCH = 84;
/** Play/Pause media key. */
KEYCODE_MEDIA_PLAY_PAUSE= 85;
/** Stop media key. */
KEYCODE_MEDIA_STOP = 86;
/** Play Next media key. */
KEYCODE_MEDIA_NEXT = 87;
/** Play Previous media key. */
KEYCODE_MEDIA_PREVIOUS = 88;
/** Rewind media key. */
KEYCODE_MEDIA_REWIND = 89;
/** Fast Forward media key. */
KEYCODE_MEDIA_FAST_FORWARD = 90;
/** Mute key.
 * Mutes the microphone, unlike {@link #KEYCODE_VOLUME_MUTE}. */
KEYCODE_MUTE = 91;
/** Page Up key. */
KEYCODE_PAGE_UP = 92;
/** Page Down key. */
KEYCODE_PAGE_DOWN = 93;
/** Picture Symbols modifier key.
 * Used to switch symbol sets (Emoji, Kao-moji). */
KEYCODE_PICTSYMBOLS = 94; // switch symbol-sets (Emoji,Kao-moji)
/** Switch Charset modifier key.
 * Used to switch character sets (Kanji, Katakana). */
KEYCODE_SWITCH_CHARSET = 95; // switch char-sets (Kanji,Katakana)
/** A Button key.
 * On a game controller, the A button should be either the button labeled A
 * or the first button on the bottom row of controller buttons. */
KEYCODE_BUTTON_A = 96;
/** B Button key.
 * On a game controller, the B button should be either the button labeled B
 * or the second button on the bottom row of controller buttons. */
KEYCODE_BUTTON_B = 97;
/** C Button key.
 * On a game controller, the C button should be either the button labeled C
 * or the third button on the bottom row of controller buttons. */
KEYCODE_BUTTON_C = 98;
/** X Button key.
 * On a game controller, the X button should be either the button labeled X
 * or the first button on the upper row of controller buttons. */
KEYCODE_BUTTON_X = 99;
/** Y Button key.
 * On a game controller, the Y button should be either the button labeled Y
 * or the second button on the upper row of controller buttons. */
KEYCODE_BUTTON_Y = 100;
/** Z Button key.
 * On a game controller, the Z button should be either the button labeled Z
 * or the third button on the upper row of controller buttons. */
KEYCODE_BUTTON_Z = 101;
/** L1 Button key.
 * On a game controller, the L1 button should be either the button labeled L1 (or L)
 * or the top left trigger button. */
KEYCODE_BUTTON_L1 = 102;
/** R1 Button key.
 * On a game controller, the R1 button should be either the button labeled R1 (or R)
 * or the top right trigger button. */
KEYCODE_BUTTON_R1 = 103;
/** L2 Button key.
 * On a game controller, the L2 button should be either the button labeled L2
 * or the bottom left trigger button. */
KEYCODE_BUTTON_L2 = 104;
/** R2 Button key.
 * On a game controller, the R2 button should be either the button labeled R2
 * or the bottom right trigger button. */
KEYCODE_BUTTON_R2 = 105;
/** Left Thumb Button key.
 * On a game controller, the left thumb button indicates that the left (or only)
 * joystick is pressed. */
KEYCODE_BUTTON_THUMBL = 106;
/** Right Thumb Button key.
 * On a game controller, the right thumb button indicates that the right
 * joystick is pressed. */
KEYCODE_BUTTON_THUMBR = 107;
/** Start Button key.
 * On a game controller, the button labeled Start. */
KEYCODE_BUTTON_START = 108;
/** Select Button key.
 * On a game controller, the button labeled Select. */
KEYCODE_BUTTON_SELECT = 109;
/** Mode Button key.
 * On a game controller, the button labeled Mode. */
KEYCODE_BUTTON_MODE = 110;
/** Escape key. */
KEYCODE_ESCAPE = 111;
/** Forward Delete key.
 * Deletes characters ahead of the insertion point, unlike {@link #KEYCODE_DEL}. */
KEYCODE_FORWARD_DEL = 112;
/** Left Control modifier key. */
KEYCODE_CTRL_LEFT = 113;
/** Right Control modifier key. */
KEYCODE_CTRL_RIGHT = 114;
/** Caps Lock key. */
KEYCODE_CAPS_LOCK = 115;
/** Scroll Lock key. */
KEYCODE_SCROLL_LOCK = 116;
/** Left Meta modifier key. */
KEYCODE_META_LEFT = 117;
/** Right Meta modifier key. */
KEYCODE_META_RIGHT = 118;
/** Function modifier key. */
KEYCODE_FUNCTION = 119;
/** System Request / Print Screen key. */
KEYCODE_SYSRQ = 120;
/** Break / Pause key. */
KEYCODE_BREAK = 121;
/** Home Movement key.
 * Used for scrolling or moving the cursor around to the start of a line
 * or to the top of a list. */
KEYCODE_MOVE_HOME = 122;
/** End Movement key.
 * Used for scrolling or moving the cursor around to the end of a line
 * or to the bottom of a list. */
KEYCODE_MOVE_END = 123;
/** Insert key.
 * Toggles insert / overwrite edit mode. */
KEYCODE_INSERT = 124;
/** Forward key.
 * Navigates forward in the history stack. Complement of {@link #KEYCODE_BACK}. */
KEYCODE_FORWARD = 125;
/** Play media key. */
KEYCODE_MEDIA_PLAY = 126;
/** Pause media key. */
KEYCODE_MEDIA_PAUSE = 127;
/** Close media key.
 * May be used to close a CD tray, for example. */
KEYCODE_MEDIA_CLOSE = 128;
/** Eject media key.
 * May be used to eject a CD tray, for example. */
KEYCODE_MEDIA_EJECT = 129;
/** Record media key. */
KEYCODE_MEDIA_RECORD = 130;
/** F1 key. */
KEYCODE_F1 = 131;
/** F2 key. */
KEYCODE_F2 = 132;
/** F3 key. */
KEYCODE_F3 = 133;
/** F4 key. */
KEYCODE_F4 = 134;
/** F5 key. */
KEYCODE_F5 = 135;
/** F6 key. */
KEYCODE_F6 = 136;
/** F7 key. */
KEYCODE_F7 = 137;
/** F8 key. */
KEYCODE_F8 = 138;
/** F9 key. */
KEYCODE_F9 = 139;
/** F10 key. */
KEYCODE_F10 = 140;
/** F11 key. */
KEYCODE_F11 = 141;
/** F12 key. */
KEYCODE_F12 = 142;
/** Num Lock key.
 * This is the Num Lock key; it is different from {@link #KEYCODE_NUM}.
 * This key alters the behavior of other keys on the numeric keypad. */
KEYCODE_NUM_LOCK = 143;
/** Numeric keypad '0' key. */
KEYCODE_NUMPAD_0 = 144;
/** Numeric keypad '1' key. */
KEYCODE_NUMPAD_1 = 145;
/** Numeric keypad '2' key. */
KEYCODE_NUMPAD_2 = 146;
/** Numeric keypad '3' key. */
KEYCODE_NUMPAD_3 = 147;
/** Numeric keypad '4' key. */
KEYCODE_NUMPAD_4 = 148;
/** Numeric keypad '5' key. */
KEYCODE_NUMPAD_5 = 149;
/** Numeric keypad '6' key. */
KEYCODE_NUMPAD_6 = 150;
/** Numeric keypad '7' key. */
KEYCODE_NUMPAD_7 = 151;
/** Numeric keypad '8' key. */
KEYCODE_NUMPAD_8 = 152;
/** Numeric keypad '9' key. */
KEYCODE_NUMPAD_9 = 153;
/** Numeric keypad '/' key (for division). */
KEYCODE_NUMPAD_DIVIDE = 154;
/** Numeric keypad '*' key (for multiplication). */
KEYCODE_NUMPAD_MULTIPLY = 155;
/** Numeric keypad '-' key (for subtraction). */
KEYCODE_NUMPAD_SUBTRACT = 156;
/** Numeric keypad '+' key (for addition). */
KEYCODE_NUMPAD_ADD = 157;
/** Numeric keypad '.' key (for decimals or digit grouping). */
KEYCODE_NUMPAD_DOT = 158;
/** Numeric keypad ',' key (for decimals or digit grouping). */
KEYCODE_NUMPAD_COMMA = 159;
/** Numeric keypad Enter key. */
KEYCODE_NUMPAD_ENTER = 160;
/** Numeric keypad '=' key. */
KEYCODE_NUMPAD_EQUALS = 161;
/** Numeric keypad '(' key. */
KEYCODE_NUMPAD_LEFT_PAREN = 162;
/** Numeric keypad ')' key. */
KEYCODE_NUMPAD_RIGHT_PAREN = 163;
/** Volume Mute key.
 * Mutes the speaker, unlike {@link #KEYCODE_MUTE}.
 * This key should normally be implemented as a toggle such that the first press
 * mutes the speaker and the second press restores the original volume. */
KEYCODE_VOLUME_MUTE = 164;
/** Info key.
 * Common on TV remotes to show additional information related to what is
 * currently being viewed. */
KEYCODE_INFO = 165;
/** Channel up key.
 * On TV remotes, increments the television channel. */
KEYCODE_CHANNEL_UP = 166;
/** Channel down key.
 * On TV remotes, decrements the television channel. */
KEYCODE_CHANNEL_DOWN = 167;
/** Zoom in key. */
KEYCODE_ZOOM_IN = 168;
/** Zoom out key. */
KEYCODE_ZOOM_OUT = 169;
/** TV key.
 * On TV remotes, switches to viewing live TV. */
KEYCODE_TV = 170;
/** Window key.
 * On TV remotes, toggles picture-in-picture mode or other windowing functions. */
KEYCODE_WINDOW = 171;
/** Guide key.
 * On TV remotes, shows a programming guide. */
KEYCODE_GUIDE = 172;
/** DVR key.
 * On some TV remotes, switches to a DVR mode for recorded shows. */
KEYCODE_DVR = 173;
/** Bookmark key.
 * On some TV remotes, bookmarks content or web pages. */
KEYCODE_BOOKMARK = 174;
/** Toggle captions key.
 * Switches the mode for closed-captioning text, for example during television shows. */
KEYCODE_CAPTIONS = 175;
/** Settings key.
 * Starts the system settings activity. */
KEYCODE_SETTINGS = 176;
/** TV power key.
 * On TV remotes, toggles the power on a television screen. */
KEYCODE_TV_POWER = 177;
/** TV input key.
 * On TV remotes, switches the input on a television screen. */
KEYCODE_TV_INPUT = 178;
/** Set-top-box power key.
 * On TV remotes, toggles the power on an external Set-top-box. */
KEYCODE_STB_POWER = 179;
/** Set-top-box input key.
 * On TV remotes, switches the input mode on an external Set-top-box. */
KEYCODE_STB_INPUT = 180;
/** A/V Receiver power key.
 * On TV remotes, toggles the power on an external A/V Receiver. */
KEYCODE_AVR_POWER = 181;
/** A/V Receiver input key.
 * On TV remotes, switches the input mode on an external A/V Receiver. */
KEYCODE_AVR_INPUT = 182;
/** Red "programmable" key.
 * On TV remotes, acts as a contextual/programmable key. */
KEYCODE_PROG_RED = 183;
/** Green "programmable" key.
 * On TV remotes, actsas a contextual/programmable key. */
KEYCODE_PROG_GREEN = 184;
/** Yellow "programmable" key.
 * On TV remotes, acts as a contextual/programmable key. */
KEYCODE_PROG_YELLOW = 185;
/** Blue "programmable" key.
 * On TV remotes, acts as a contextual/programmable key. */
KEYCODE_PROG_BLUE = 186;
/** App switch key.
 * Should bring up the application switcher dialog. */
KEYCODE_APP_SWITCH = 187;
/** Generic Game Pad Button #1.*/
KEYCODE_BUTTON_1 = 188;
/** Generic Game Pad Button #2.*/
KEYCODE_BUTTON_2 = 189;
/** Generic Game Pad Button #3.*/
KEYCODE_BUTTON_3 = 190;
/** Generic Game Pad Button #4.*/
KEYCODE_BUTTON_4 = 191;
/** Generic Game Pad Button #5.*/
KEYCODE_BUTTON_5 = 192;
/** Generic Game Pad Button #6.*/
KEYCODE_BUTTON_6 = 193;
/** Generic Game Pad Button #7.*/
KEYCODE_BUTTON_7 = 194;
/** Generic Game Pad Button #8.*/
KEYCODE_BUTTON_8 = 195;
/** Generic Game Pad Button #9.*/
KEYCODE_BUTTON_9 = 196;
/** Generic Game Pad Button #10.*/
KEYCODE_BUTTON_10 = 197;
/** Generic Game Pad Button #11.*/
KEYCODE_BUTTON_11 = 198;
/** Generic Game Pad Button #12.*/
KEYCODE_BUTTON_12 = 199;
/** Generic Game Pad Button #13.*/
KEYCODE_BUTTON_13 = 200;
/** Generic Game Pad Button #14.*/
KEYCODE_BUTTON_14 = 201;
/** Generic Game Pad Button #15.*/
KEYCODE_BUTTON_15 = 202;
/** Generic Game Pad Button #16.*/
KEYCODE_BUTTON_16 = 203;
/** Language Switch key.
 * Toggles the current input language such as switching between English and Japanese on
 * a QWERTY keyboard. On some devices, the same function may be performed by
 * pressing Shift+Spacebar. */
KEYCODE_LANGUAGE_SWITCH = 204;
/** Manner Mode key.
 * Toggles silent or vibrate mode on and off to make the device behave more politely
 * in certain settings such as on a crowded train. On some devices, the key may only
 * operate when long-pressed. */
KEYCODE_MANNER_MODE = 205;
/** 3D Mode key.
 * Toggles the display between 2D and 3D mode. */
KEYCODE_3D_MODE = 206;
/** Contacts special function key.
 * Used to launch an address book application. */
KEYCODE_CONTACTS = 207;
/** Calendar special function key.
 * Used to launch a calendar application. */
KEYCODE_CALENDAR = 208;
/** Music special function key.
 * Used to launch a music player application. */
KEYCODE_MUSIC = 209;
/** Calculator special function key.
 * Used to launch a calculator application. */
KEYCODE_CALCULATOR = 210;
/** Japanese full-width / half-width key. */
KEYCODE_ZENKAKU_HANKAKU = 211;
/** Japanese alphanumeric key. */
KEYCODE_EISU = 212;
/** Japanese non-conversion key. */
KEYCODE_MUHENKAN = 213;
/** Japanese conversion key. */
KEYCODE_HENKAN = 214;
/** Japanese katakana / hiragana key. */
KEYCODE_KATAKANA_HIRAGANA = 215;
/** Japanese Yen key. */
KEYCODE_YEN = 216;
/** Japanese Ro key. */
KEYCODE_RO = 217;
/** Japanese kana key. */
KEYCODE_KANA = 218;
/** Assist key.
 * Launches the global assist activity. Not delivered to applications. */
KEYCODE_ASSIST = 219;
/** Brightness Down key.
 * Adjusts the screen brightness down. */
KEYCODE_BRIGHTNESS_DOWN = 220;
/** Brightness Up key.
 * Adjusts the screen brightness up. */
KEYCODE_BRIGHTNESS_UP = 221;
/** Audio Track key.
 * Switches the audio tracks. */
KEYCODE_MEDIA_AUDIO_TRACK = 222;
/** Sleep key.
 * Puts the device to sleep. Behaves somewhat like {@link #KEYCODE_POWER} but it
 * has no effect if the device is already asleep. */
KEYCODE_SLEEP = 223;
/** Wakeup key.
 * Wakes up the device. Behaves somewhat like {@link #KEYCODE_POWER} but it
 * has no effect if the device is already awake. */
KEYCODE_WAKEUP = 224;
/** Pairing key.
 * Initiates peripheral pairing mode. Useful for pairing remote control
 * devices or game controllers, especially if no other input mode is
 * available. */
KEYCODE_PAIRING = 225;
/** Media Top Menu key.
 * Goes to the top of media menu. */
KEYCODE_MEDIA_TOP_MENU = 226;
/** '11' key. */
KEYCODE_11 = 227;
/** '12' key. */
KEYCODE_12 = 228;
/** Last Channel key.
 * Goes to the last viewed channel. */
KEYCODE_LAST_CHANNEL = 229;
/** TV data service key.
 * Displays data services like weather, sports. */
KEYCODE_TV_DATA_SERVICE = 230;
/** Voice Assist key.
 * Launches the global voice assist activity. Not delivered to applications. */
KEYCODE_VOICE_ASSIST = 231;
/** Radio key.
 * Toggles TV service / Radio service. */
KEYCODE_TV_RADIO_SERVICE = 232;
/** Teletext key.
 * Displays Teletext service. */
KEYCODE_TV_TELETEXT = 233;
/** Number entry key.
 * Initiates to enter multi-digit channel nubmber when each digit key is assigned
 * for selecting separate channel. Corresponds to Number Entry Mode (0x1D) of CEC
 * User Control Code. */
KEYCODE_TV_NUMBER_ENTRY = 234;
/** Analog Terrestrial key.
 * Switches to analog terrestrial broadcast service. */
KEYCODE_TV_TERRESTRIAL_ANALOG = 235;
/** Digital Terrestrial key.
 * Switches to digital terrestrial broadcast service. */
KEYCODE_TV_TERRESTRIAL_DIGITAL = 236;
/** Satellite key.
 * Switches to digital satellite broadcast service. */
KEYCODE_TV_SATELLITE = 237;
/** BS key.
 * Switches to BS digital satellite broadcasting service available in Japan. */
KEYCODE_TV_SATELLITE_BS = 238;
/** CS key.
 * Switches to CS digital satellite broadcasting service available in Japan. */
KEYCODE_TV_SATELLITE_CS = 239;
/** BS/CS key.
 * Toggles between BS and CS digital satellite services. */
KEYCODE_TV_SATELLITE_SERVICE = 240;
/** Toggle Network key.
 * Toggles selecting broacast services. */
KEYCODE_TV_NETWORK = 241;
/** Antenna/Cable key.
 * Toggles broadcast input source between antenna and cable. */
KEYCODE_TV_ANTENNA_CABLE = 242;
/** HDMI #1 key.
 * Switches to HDMI input #1. */
KEYCODE_TV_INPUT_HDMI_1 = 243;
/** HDMI #2 key.
 * Switches to HDMI input #2. */
KEYCODE_TV_INPUT_HDMI_2 = 244;
/** HDMI #3 key.
 * Switches to HDMI input #3. */
KEYCODE_TV_INPUT_HDMI_3 = 245;
/** HDMI #4 key.
 * Switches to HDMI input #4. */
KEYCODE_TV_INPUT_HDMI_4 = 246;
/** Composite #1 key.
 * Switches to composite video input #1. */
KEYCODE_TV_INPUT_COMPOSITE_1 = 247;
/** Composite #2 key.
 * Switches to composite video input #2. */
KEYCODE_TV_INPUT_COMPOSITE_2 = 248;
/** Component #1 key.
 * Switches to component video input #1. */
KEYCODE_TV_INPUT_COMPONENT_1 = 249;
/** Component #2 key.
 * Switches to component video input #2. */
KEYCODE_TV_INPUT_COMPONENT_2 = 250;
/** VGA #1 key.
 * Switches to VGA (analog RGB) input #1. */
KEYCODE_TV_INPUT_VGA_1 = 251;
/** Audio description key.
 * Toggles audio description off / on. */
KEYCODE_TV_AUDIO_DESCRIPTION = 252;
/** Audio description mixing volume up key.
 * Louden audio description volume as compared with normal audio volume. */
KEYCODE_TV_AUDIO_DESCRIPTION_MIX_UP = 253;
/** Audio description mixing volume down key.
 * Lessen audio description volume as compared with normal audio volume. */
KEYCODE_TV_AUDIO_DESCRIPTION_MIX_DOWN = 254;
/** Zoom mode key.
 * Changes Zoom mode (Normal, Full, Zoom, Wide-zoom, etc.) */
KEYCODE_TV_ZOOM_MODE = 255;
/** Contents menu key.
 * Goes to the title list. Corresponds to Contents Menu (0x0B) of CEC User Control
 * Code */
KEYCODE_TV_CONTENTS_MENU = 256;
/** Media context menu key.
 * Goes to the context menu of media contents. Corresponds to Media Context-sensitive
 * Menu (0x11) of CEC User Control Code. */
KEYCODE_TV_MEDIA_CONTEXT_MENU = 257;
/** Timer programming key.
 * Goes to the timer recording menu. Corresponds to Timer Programming (0x54) of
 * CEC User Control Code. */
KEYCODE_TV_TIMER_PROGRAMMING = 258;
/** Help key. */
KEYCODE_HELP = 259;
/** Navigate to previous key.
 * Goes backward by one item in an ordered collection of items. */
KEYCODE_NAVIGATE_PREVIOUS = 260;
/** Navigate to next key.
 * Advances to the next item in an ordered collection of items. */
KEYCODE_NAVIGATE_NEXT = 261;
/** Navigate in key.
 * Activates the item that currently has focus or expands to the next level of a navigation
 * hierarchy. */
KEYCODE_NAVIGATE_IN = 262;
/** Navigate out key.
 * Backs out one level of a navigation hierarchy or collapses the item that currently has
 * focus. */
KEYCODE_NAVIGATE_OUT = 263;
/** Primary stem key for Wear
 * Main power/reset button on watch. */
KEYCODE_STEM_PRIMARY = 264;
/** Generic stem key 1 for Wear */
KEYCODE_STEM_1 = 265;
/** Generic stem key 2 for Wear */
KEYCODE_STEM_2 = 266;
/** Generic stem key 3 for Wear */
KEYCODE_STEM_3 = 267;
/** Directional Pad Up-Left */
KEYCODE_DPAD_UP_LEFT = 268;
/** Directional Pad Down-Left */
KEYCODE_DPAD_DOWN_LEFT = 269;
/** Directional Pad Up-Right */
KEYCODE_DPAD_UP_RIGHT = 270;
/** Directional Pad Down-Right */
KEYCODE_DPAD_DOWN_RIGHT = 271;
/** Skip forward media key. */
KEYCODE_MEDIA_SKIP_FORWARD = 272;
/** Skip backward media key. */
KEYCODE_MEDIA_SKIP_BACKWARD = 273;
/** Step forward media key.
 * Steps media forward, one frame at a time. */
KEYCODE_MEDIA_STEP_FORWARD = 274;
/** Step backward media key.
 * Steps media backward, one frame at a time. */
KEYCODE_MEDIA_STEP_BACKWARD = 275;
/** put device to sleep unless a wakelock is held. */
KEYCODE_SOFT_SLEEP = 276;
/** Cut key. */
KEYCODE_CUT = 277;
/** Copy key. */
KEYCODE_COPY = 278;
/** Paste key. */
KEYCODE_PASTE = 279;
/** Consumed by the system for navigation up */
KEYCODE_SYSTEM_NAVIGATION_UP = 280;
/** Consumed by the system for navigation down */
KEYCODE_SYSTEM_NAVIGATION_DOWN = 281;
/** Consumed by the system for navigation left*/
KEYCODE_SYSTEM_NAVIGATION_LEFT = 282;
/** Consumed by the system for navigation right */
KEYCODE_SYSTEM_NAVIGATION_RIGHT = 283;

Notes

  • Currently the last key code is KEYCODE_SYSTEM_NAVIGATION_RIGHT, which is 283 (but check the source code to make sure this is still true). So you could loop through them like this:

    for (int keyCode = 0; keyCode <= 283; keyCode++) {
    
    }
    
  • Most input to EditText (or a custom view that accepts keyboard input) from an Input Method Editor (IME) is done using an Input Connection, so many key codes are not sent at all in this case. See this answer.

What is a Windows Handle?

It's an abstract reference value to a resource, often memory or an open file, or a pipe.

Properly, in Windows, (and generally in computing) a handle is an abstraction which hides a real memory address from the API user, allowing the system to reorganize physical memory transparently to the program. Resolving a handle into a pointer locks the memory, and releasing the handle invalidates the pointer. In this case think of it as an index into a table of pointers... you use the index for the system API calls, and the system can change the pointer in the table at will.

Alternatively a real pointer may be given as the handle when the API writer intends that the user of the API be insulated from the specifics of what the address returned points to; in this case it must be considered that what the handle points to may change at any time (from API version to version or even from call to call of the API that returns the handle) - the handle should therefore be treated as simply an opaque value meaningful only to the API.

I should add that in any modern operating system, even the so-called "real pointers" are still opaque handles into the virtual memory space of the process, which enables the O/S to manage and rearrange memory without invalidating the pointers within the process.

C++ - Decimal to binary converting

Your solution needs a modification. The final string should be reversed before returning:

std::reverse(r.begin(), r.end());
return r;

WPF checkbox binding

Should be easier than that. Just use:

<Checkbox IsChecked="{Binding Path=myVar, UpdateSourceTrigger=PropertyChanged}" />

Copy multiple files in Python

import os
import shutil
os.chdir('C:\\') #Make sure you add your source and destination path below

dir_src = ("C:\\foooo\\")
dir_dst = ("C:\\toooo\\")

for filename in os.listdir(dir_src):
    if filename.endswith('.txt'):
        shutil.copy( dir_src + filename, dir_dst)
    print(filename)

Java ArrayList - how can I tell if two lists are equal, order not mattering?

Solution which leverages CollectionUtils subtract method:

import static org.apache.commons.collections15.CollectionUtils.subtract;

public class CollectionUtils {
  static public <T> boolean equals(Collection<? extends T> a, Collection<? extends T> b) {
    if (a == null && b == null)
      return true;
    if (a == null || b == null || a.size() != b.size())
      return false;
    return subtract(a, b).size() == 0 && subtract(a, b).size() == 0;
  }
}

Python: "Indentation Error: unindent does not match any outer indentation level"

I had this same problem and it had nothing to do with tabs. This was my problem code:

def genericFunction(variable):

    for line in variable:

       line = variable


   if variable != None:
      return variable

Note the above for is indented with more spaces than the line that starts with if. This is bad. All your indents must be consistent. So I guess you could say I had a stray space and not a stray tab.

Loading basic HTML in Node.js

try this one:

var http = require('http');
var fs = require('fs');
var PORT = 8080;

http.createServer((req, res) => {
    fs.readFile('./' + req.url, (err, data) => {
        if (!err) {
            var dotoffset = req.url.lastIndexOf('.');
            var mimetype = dotoffset == -1 ? 'text/plaint' : {
                '.html': 'text/html',
                '.css': 'text/css',
                '.js': 'text/javascript',
                '.jpg': 'image/jpeg',
                '.png': 'image/png',
                '.ico': 'image/x-icon',
                '.gif': 'image/gif'
            }[ req.url.substr(dotoffset) ];
            res.setHeader('Content-Type', mimetype);
            res.end(data);
            console.log(req.url, mimetype);
        } else {
            console.log('File not fount: ' + req.url);
            res.writeHead(404, "Not Found");
            res.end();
        }
    });
 }).listen(PORT);

With this, you can include js, css source-codes when linking them and you can load icons, imgs, gifs. And if you want, you can add more if you need.

How to run multiple SQL commands in a single SQL connection?

Multiple Non-query example if anyone is interested.

using (OdbcConnection DbConnection = new OdbcConnection("ConnectionString"))
{
  DbConnection.Open();
  using (OdbcCommand DbCommand = DbConnection.CreateCommand())
  {
    DbCommand.CommandText = "INSERT...";
    DbCommand.Parameters.Add("@Name", OdbcType.Text, 20).Value = "name";
    DbCommand.ExecuteNonQuery();

    DbCommand.Parameters.Clear();
    DbCommand.Parameters.Add("@Name", OdbcType.Text, 20).Value = "name2";
    DbCommand.ExecuteNonQuery();
  }
}

nullable object must have a value

Assign the members directly without the .Value part:

DateTimeExtended(DateTimeExtended myNewDT)
{
   this.MyDateTime = myNewDT.MyDateTime;
   this.otherdata = myNewDT.otherdata;
}

HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

You can use this for the Width of your DataTemplate:

Width="{Binding ActualWidth,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ScrollContentPresenter}}}"

Make sure your DataTemplate root has Margin="0" (you can use some panel as the root and set the Margin to the children of that root)

How to detect scroll position of page using jQuery

GET Scroll Position:

var scrolled_val = window.scrollY;

DETECT Scroll Position:

$(window).scroll
(
     function (event) 
     {
          var scrolled_val = window.scrollY;
          alert(scrolled_val);
     }
 );

Binary Data in JSON String. Something better than Base64

I ran into the same problem, and thought I'd share a solution: multipart/form-data.

By sending a multipart form you send first as string your JSON meta-data, and then separately send as raw binary (image(s), wavs, etc) indexed by the Content-Disposition name.

Here's a nice tutorial on how to do this in obj-c, and here is a blog article that explains how to partition the string data with the form boundary, and separate it from the binary data.

The only change you really need to do is on the server side; you will have to capture your meta-data which should reference the POST'ed binary data appropriately (by using a Content-Disposition boundary).

Granted it requires additional work on the server side, but if you are sending many images or large images, this is worth it. Combine this with gzip compression if you want.

IMHO sending base64 encoded data is a hack; the RFC multipart/form-data was created for issues such as this: sending binary data in combination with text or meta-data.

How to change current Theme at runtime in Android

This way work for me:

  @Override
protected void onCreate(Bundle savedInstanceState) {
    setTheme(GApplication.getInstance().getTheme());
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
}

Then you want to change a new theme:

GApplication.getInstance().setTheme(R.style.LightTheme);
recreate();

Java Webservice Client (Best way)

Some ideas in the following answer:

Steps in creating a web service using Axis2 - The client code

Gives an example of a Groovy client invoking the ADB classes generated from the WSDL.

There are lots of web service frameworks out there...

How do you rotate a two dimensional array?

Nick's answer would work for an NxM array too with only a small modification (as opposed to an NxN).

string[,] orig = new string[n, m];
string[,] rot = new string[m, n];

...

for ( int i=0; i < n; i++ )
  for ( int j=0; j < m; j++ )
    rot[j, n - i - 1] = orig[i, j];

One way to think about this is that you have moved the center of the axis (0,0) from the top left corner to the top right corner. You're simply transposing from one to the other.

'System.OutOfMemoryException' was thrown when there is still plenty of memory free

If you do not need the Visual Studio Hosting Process:

Uncheck the option: Project->Properties->Debug->Enable the Visual Studio Hosting Process

And then build.

If you still face the problem:

Go to Project->Properties->Build Events->Post-Build Event Command line and paste the following:

call "$(DevEnvDir)..\..\vc\vcvarsall.bat" x86
"$(DevEnvDir)..\..\vc\bin\EditBin.exe" "$(TargetPath)"  /LARGEADDRESSAWARE

Now, build the project.

Python object.__repr__(self) should be an expression?

To see how the repr works within a class, run the following code, first with and then without the repr method.

class Coordinate (object):
    def __init__(self,x,y):
        self.x = x
        self.y = y

    def getX(self):
        # Getter method for a Coordinate object's x coordinate.
        # Getter methods are better practice than just accessing an attribute directly
        return self.x
    def getY(self):

        # Getter method for a Coordinate object's y coordinate
        return self.y

    def __repr__(self):  #remove this and the next line and re-run
        return 'Coordinate(' + str(self.getX()) + ',' + str(self.getY()) + ')' 

>>>c = Coordinate(2,-8)
>>>print(c)

Android Crop Center of Bitmap

public static Bitmap resizeAndCropCenter(Bitmap bitmap, int size, boolean recycle) {
    int w = bitmap.getWidth();
    int h = bitmap.getHeight();
    if (w == size && h == size) return bitmap;
    // scale the image so that the shorter side equals to the target;
    // the longer side will be center-cropped.
    float scale = (float) size / Math.min(w,  h);
    Bitmap target = Bitmap.createBitmap(size, size, getConfig(bitmap));
    int width = Math.round(scale * bitmap.getWidth());
    int height = Math.round(scale * bitmap.getHeight());
    Canvas canvas = new Canvas(target);
    canvas.translate((size - width) / 2f, (size - height) / 2f);
    canvas.scale(scale, scale);
    Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG);
    canvas.drawBitmap(bitmap, 0, 0, paint);
    if (recycle) bitmap.recycle();
    return target;
}

private static Bitmap.Config getConfig(Bitmap bitmap) {
    Bitmap.Config config = bitmap.getConfig();
    if (config == null) {
        config = Bitmap.Config.ARGB_8888;
    }
    return config;
}

Difference Between Schema / Database in MySQL

Microsoft SQL Server for instance, Schemas refer to a single user and is another level of a container in the order of indicating the server, database, schema, tables, and objects.

For example, when you are intending to update dbo.table_a and the syntax isn't full qualified such as UPDATE table.a the DBMS can't decide to use the intended table. Essentially by default the DBMS will utilize myuser.table_a

Android toolbar center title and custom font

I found another way to add custom toolbar without any adicional Java/Kotlin code.

  • First: create a XML with your custom toolbar layout with AppBarLayout as the parent:

    <?xml version="1.0" encoding="utf-8"?>
    <android.support.design.widget.AppBarLayout                     
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">
    
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/AppTheme.PopupOverlay">
    
        <ImageView
            android:layout_width="80dp"
            android:layout_height="wrap_content"
            android:layout_gravity="right"
            android:layout_marginEnd="@dimen/magin_default"
            android:src="@drawable/logo" />
    
    </android.support.v7.widget.Toolbar>
    

  • Second: Include the toolbar in your layout:

    <?xml version="1.0" encoding="utf-8"?>                
    <android.support.constraint.ConstraintLayout 
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/blue"
        tools:context=".app.MainAcitivity"
        tools:layout_editor_absoluteY="81dp">
    
        <include
            layout="@layout/toolbar_inicio"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />
    
        <!-- Put your layout here -->
    
    </android.support.constraint.ConstraintLayout>
    

default web page width - 1024px or 980px?

even there is no right or wrong answer for this question , but I personally prefer 960px width . since all modern monitors support at least 1024 × 768 pixel resolution. 960 is divisible by 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 48, 60, 64, 80, 96, 120, 160, 192, 240, 320 and 480. This makes it a highly flexible base number to work with.

see this article that shows most popular screens resolutions 2013-2014 in US and UK : http://www.hobo-web.co.uk/best-screen-size/

Instagram how to get my user id from username?

Most of these answers are invalid after the 6/1/2016 Instagram API changes. The best solution now is here. Go to your feed on instagram.com, copy the link address for any of your pictures, and paste it into the textbox on that page. Worked like a charm.

How to convert Set to Array?

SIMPLEST ANSWER

just spread the set inside []

let mySet = new Set()
mySet.add(1)
mySet.add(5)
mySet.add(5) 
let arr = [...mySet ]

Result: [1,5]

SQL Server: Database stuck in "Restoring" state

All the WITH RECOVERY based options did not work for me.

What did was to do the complete restore from Management Studio.

USE [master]
RESTORE DATABASE Sales_SSD
FROM  DISK = N'D:\databaseBackups02\Daily_Sales_20150309_0941.bak' 
WITH  FILE = 1,  
MOVE N'Sales_Data' TO N'C:\Data\SSD\Sales.mdf',  
MOVE N'Sales_Log' TO N'C:\Data\SSD\Sales_1.ldf',  
NOUNLOAD,  REPLACE,  STATS = 5

How to implement a tree data-structure in Java?

public class Tree {
    private List<Tree> leaves = new LinkedList<Tree>();
    private Tree parent = null;
    private String data;

    public Tree(String data, Tree parent) {
        this.data = data;
        this.parent = parent;
    }
}

Obviously you can add utility methods to add/remove children.

Checking character length in ruby

Ruby provides a built-in function for checking the length of a string. Say it's called s:

if s.length <= 25
  # We're OK
else
  # Too long
end

How to format a numeric column as phone number in SQL

You Can Use FORMAT if you column is a number Syntax like FORMAT ( value, format [, culture ] ) In use like FORMAT ( @d, 'D', 'en-US' ) or FORMAT(123456789,'###-##-####') (But This works for only SQL SERVER 2012 And After)

In Use Like UPDATE TABLE_NAME SET COLUMN_NAME = FORMAT(COLUMN_NAME ,'###-##-####')

And

if your column is Varchar Or Nvarchar use do like this CONCAT(SUBSTRING(CELLPHONE,0,4),' ',SUBSTRING(CELLPHONE,4,3),' ',SUBSTRING(CELLPHONE,7,2) ,' ',SUBSTRING(CELLPHONE,9,2) )

You can always get help from

https://msdn.microsoft.com/en-us/library/hh213505.aspx

How to change link color (Bootstrap)

You can use .text-reset class to reset the color from default blue to anything you want. Hopefully this is helpful.

Source: https://getbootstrap.com/docs/4.5/utilities/text/#reset-color

HTML/CSS - Adding an Icon to a button

<a href="#" class="btnTest">Test</a>


.btnTest{
   background:url('images/icon.png') no-repeat left center;
   padding-left:20px;
}    

How do you get assembler output from C/C++ source in gcc?

From: http://www.delorie.com/djgpp/v2faq/faq8_20.html

gcc -c -g -Wa,-a,-ad [other GCC options] foo.c > foo.lst

in alternative to PhirePhly's answer Or just use -S as everyone said.

Why won't my PHP app send a 404 error?

If you want to show the server’s default 404 page, you can load it in a frame like this:

echo '<iframe src="/something-bogus" width="100%" height="100%" frameBorder="0" border="0" scrolling="no"></iframe>';

JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object

For Java 8 on a *nix OS, go to <jdk root>/jre/lib (for me, /usr/java/jdk1.8.0_05/jre/lib). From this directory, execute:

../../bin/unpack200 rt.pack rt.jar
../../bin/unpack200 jsse.pack jsse.rar
../../bin/unpack200 charsets.pack charsets.jar

To prevent version problems in case you have another JRE installed, use the same unpack200 that ships with the JRE you are fixing – that is, from the command line, use ../../bin/unpack200 (for me, this expands to /usr/java/jdk1.8.0_05/bin/unpack200), not just unpack200.

Transfer data between databases with PostgreSQL

I just had to do this exact thing so I figured I'd post the recipe here. This assumes that both databases are on the same server.

First, copy the table from the old db to the new db (because apparently you can't move data between databases). At the commandline:

pg_dump -U postgres -t <old_table> <old_database> | psql -U postgres -d <new_database>

# Just adding extra space here so scrollbar doesn't hide the command

Next, grant permissions of the copied table to the user of the new database. Log into psql:

psql -U postgres -d <new_database>

ALTER TABLE <old_table> OWNER TO <new_user>;

\q

Finally, copy data from the old table to the new table. Log in as the new user and then:

INSERT INTO <new_table> (field1, field2, field3) 
SELECT field1, field2, field3 from <old_table>;

Done!

C++ program converts fahrenheit to celsius

It is the simplest one I could come up with, so wanted to share here,

#include<iostream.h>
#include<conio.h>
void main()
{
//clear the screen.
clrscr();
//declare variable type float
float cel, fah;
//Input the Temperature in given unit save them in ‘cel’
cout<<”Enter the Temperature in Celsius”<<endl;
cin>>cel;
//convert and save it in ‘fah’
fah=1.8*cel+32.0;
//show the output ‘fah’
cout<<”Temperature in Fahrenheit is “<<fah;
//get character
getch();
}

Source: Celsius to Fahrenheit

How to format font style and color in echo

echo '< span style = "font-color: #ff0000"> Movie List for {$key} 2013 </span>';

Peak signal detection in realtime timeseries data

Robust peak detection algorithm (using z-scores)

I came up with an algorithm that works very well for these types of datasets. It is based on the principle of dispersion: if a new datapoint is a given x number of standard deviations away from some moving mean, the algorithm signals (also called z-score). The algorithm is very robust because it constructs a separate moving mean and deviation, such that signals do not corrupt the threshold. Future signals are therefore identified with approximately the same accuracy, regardless of the amount of previous signals. The algorithm takes 3 inputs: lag = the lag of the moving window, threshold = the z-score at which the algorithm signals and influence = the influence (between 0 and 1) of new signals on the mean and standard deviation. For example, a lag of 5 will use the last 5 observations to smooth the data. A threshold of 3.5 will signal if a datapoint is 3.5 standard deviations away from the moving mean. And an influence of 0.5 gives signals half of the influence that normal datapoints have. Likewise, an influence of 0 ignores signals completely for recalculating the new threshold. An influence of 0 is therefore the most robust option (but assumes stationarity); putting the influence option at 1 is least robust. For non-stationary data, the influence option should therefore be put somewhere between 0 and 1.

It works as follows:

Pseudocode

# Let y be a vector of timeseries data of at least length lag+2
# Let mean() be a function that calculates the mean
# Let std() be a function that calculates the standard deviaton
# Let absolute() be the absolute value function

# Settings (the ones below are examples: choose what is best for your data)
set lag to 5;          # lag 5 for the smoothing functions
set threshold to 3.5;  # 3.5 standard deviations for signal
set influence to 0.5;  # between 0 and 1, where 1 is normal influence, 0.5 is half

# Initialize variables
set signals to vector 0,...,0 of length of y;   # Initialize signal results
set filteredY to y(1),...,y(lag)                # Initialize filtered series
set avgFilter to null;                          # Initialize average filter
set stdFilter to null;                          # Initialize std. filter
set avgFilter(lag) to mean(y(1),...,y(lag));    # Initialize first value
set stdFilter(lag) to std(y(1),...,y(lag));     # Initialize first value

for i=lag+1,...,t do
  if absolute(y(i) - avgFilter(i-1)) > threshold*stdFilter(i-1) then
    if y(i) > avgFilter(i-1) then
      set signals(i) to +1;                     # Positive signal
    else
      set signals(i) to -1;                     # Negative signal
    end
    set filteredY(i) to influence*y(i) + (1-influence)*filteredY(i-1);
  else
    set signals(i) to 0;                        # No signal
    set filteredY(i) to y(i);
  end
  set avgFilter(i) to mean(filteredY(i-lag),...,filteredY(i));
  set stdFilter(i) to std(filteredY(i-lag),...,filteredY(i));
end

Rules of thumb for selecting good parameters for your data can be found below.


Demo

Demonstration of robust thresholding algorithm

The Matlab code for this demo can be found here. To use the demo, simply run it and create a time series yourself by clicking on the upper chart. The algorithm starts working after drawing lag number of observations.


Result

For the original question, this algorithm will give the following output when using the following settings: lag = 30, threshold = 5, influence = 0:

Thresholding algorithm example


Implementations in different programming languages:


Rules of thumb for configuring the algorithm

lag: the lag parameter determines how much your data will be smoothed and how adaptive the algorithm is to changes in the long-term average of the data. The more stationary your data is, the more lags you should include (this should improve the robustness of the algorithm). If your data contains time-varying trends, you should consider how quickly you want the algorithm to adapt to these trends. I.e., if you put lag at 10, it takes 10 'periods' before the algorithm's treshold is adjusted to any systematic changes in the long-term average. So choose the lag parameter based on the trending behavior of your data and how adaptive you want the algorithm to be.

influence: this parameter determines the influence of signals on the algorithm's detection threshold. If put at 0, signals have no influence on the threshold, such that future signals are detected based on a threshold that is calculated with a mean and standard deviation that is not influenced by past signals. If put at 0.5, signals have half the influence of normal data points. Another way to think about this is that if you put the influence at 0, you implicitly assume stationarity (i.e. no matter how many signals there are, you always expect the time series to return to the same average over the long term). If this is not the case, you should put the influence parameter somewhere between 0 and 1, depending on the extent to which signals can systematically influence the time-varying trend of the data. E.g., if signals lead to a structural break of the long-term average of the time series, the influence parameter should be put high (close to 1) so the threshold can react to structural breaks quickly.

threshold: the threshold parameter is the number of standard deviations from the moving mean above which the algorithm will classify a new datapoint as being a signal. For example, if a new datapoint is 4.0 standard deviations above the moving mean and the threshold parameter is set as 3.5, the algorithm will identify the datapoint as a signal. This parameter should be set based on how many signals you expect. For example, if your data is normally distributed, a threshold (or: z-score) of 3.5 corresponds to a signaling probability of 0.00047 (from this table), which implies that you expect a signal once every 2128 datapoints (1/0.00047). The threshold therefore directly influences how sensitive the algorithm is and thereby also determines how often the algorithm signals. Examine your own data and choose a sensible threshold that makes the algorithm signal when you want it to (some trial-and-error might be needed here to get to a good threshold for your purpose).


WARNING: The code above always loops over all datapoints everytime it runs. When implementing this code, make sure to split the calculation of the signal into a separate function (without the loop). Then when a new datapoint arrives, update filteredY, avgFilter and stdFilter once. Do not recalculate the signals for all data everytime there is a new datapoint (like in the example above), that would be extremely inefficient and slow in real-time applications.

Other ways to modify the algorithm (for potential improvements) are:

  1. Use median instead of mean
  2. Use a robust measure of scale, such as the MAD, instead of the standard deviation
  3. Use a signalling margin, so the signal doesn't switch too often
  4. Change the way the influence parameter works
  5. Treat up and down signals differently (asymmetric treatment)
  6. Create a separate influence parameter for the mean and std (as in this Swift translation)

(Known) academic citations to this StackOverflow answer:

Other works using the algorithm from this answer

Other applications of the algorithm from this answer

Links to other peak detection algorithms


How to reference this algorithm:

Brakel, J.P.G. van (2014). "Robust peak detection algorithm using z-scores". Stack Overflow. Available at: https://stackoverflow.com/questions/22583391/peak-signal-detection-in-realtime-timeseries-data/22640362#22640362 (version: 2020-11-08).


If you use this function somewhere, please credit me by using above reference. If you have any questions about the algorithm, post them in the comments below or reach out to me on LinkedIn.


What is the best way to trigger onchange event in react js

The Event type input did not work for me on <select> but changing it to change works

useEffect(() => {
    var event = new Event('change', { bubbles: true });
    selectRef.current.dispatchEvent(event); // ref to the select control
}, [props.items]);

CSS: Responsive way to center a fluid div (without px width) while limiting the maximum width?

Something like this could be it?

HTML

 <div class="random">
        SOMETHING
 </div>

CSS

body{

    text-align: center;
}

.random{

    width: 60%;
    margin: auto;
    background-color: yellow;
    display:block;

}

DEMO: http://jsfiddle.net/t5Pp2/2/

Edit: adding display:block doesn't ruin the thing, so...

You can also set the margin to: margin: 0 auto 0 auto; just to be sure it centers only this way not from the top too.

"’" showing on page instead of " ' "

In DBeaver (or other editors) the script file you're working can prompt to save as UTF8 and that will change the char:

–

into

–

or

–

What's the Linq to SQL equivalent to TOP or LIMIT/OFFSET?

Use the Take method:

var foo = (from t in MyTable
           select t.Foo).Take(10);

In VB LINQ has a take expression:

Dim foo = From t in MyTable _
          Take 10 _
          Select t.Foo

From the documentation:

Take<TSource> enumerates source and yields elements until count elements have been yielded or source contains no more elements. If count exceeds the number of elements in source, all elements of source are returned.

convert a JavaScript string variable to decimal/money

You can also use the Number constructor/function (no need for a radix and usable for both integers and floats):

Number('09'); /=> 9
Number('09.0987'); /=> 9.0987

Alternatively like Andy E said in the comments you can use + for conversion

+'09'; /=> 9
+'09.0987'; /=> 9.0987

PHP header() redirect with POST variables

// from http://wezfurlong.org/blog/2006/nov/http-post-from-php-without-curl
function do_post_request($url, $data, $optional_headers = null)
{
  $params = array('http' => array(
              'method' => 'POST',
              'content' => $data
            ));
  if ($optional_headers !== null) {
    $params['http']['header'] = $optional_headers;
  }
  $ctx = stream_context_create($params);
  $fp = @fopen($url, 'rb', false, $ctx);
  if (!$fp) {
    throw new Exception("Problem with $url, $php_errormsg");
  }
  $response = @stream_get_contents($fp);
  if ($response === false) {
    throw new Exception("Problem reading data from $url, $php_errormsg");
  }
  return $response;
}

Single line sftp from terminal

To UPLOAD a single file, you will need to create a bash script. Something like the following should work on OS X if you have sshpass installed.

Usage:

sftpx <password> <user@hostname> <localfile> <remotefile>

Put this script somewhere in your path and call it sftpx:

#!/bin/bash

export RND=`cat /dev/urandom | env LC_CTYPE=C tr -cd 'a-f0-9' | head -c 32`
export TMPDIR=/tmp/$RND
export FILENAME=$(basename "$4")
export DSTDIR=$(dirname "$4")

mkdir $TMPDIR
cp "$3" $TMPDIR/$FILENAME

export SSHPASS=$1
sshpass -e sftp -oBatchMode=no -b - $2 << !
   lcd $TMPDIR
   cd $DSTDIR
   put $FILENAME
   bye
!

rm $TMPDIR/$FILENAME
rmdir $TMPDIR

How to deal with certificates using Selenium?

Javascript:

const capabilities = webdriver.Capabilities.phantomjs();
capabilities.set(webdriver.Capability.ACCEPT_SSL_CERTS, true);
capabilities.set(webdriver.Capability.SECURE_SSL, false);
capabilities.set('phantomjs.cli.args', ['--web-security=no', '--ssl-protocol=any', '--ignore-ssl-errors=yes']);
const driver = new webdriver.Builder().withCapabilities(webdriver.Capabilities.chrome(), capabilities).build();

How do I perform HTML decoding/encoding using Python/Django?

See at the bottom of this page at Python wiki, there are at least 2 options to "unescape" html.

an attempt was made to access a socket in a way forbbiden by its access permissions. why?

I had the same error happening when I had two different ASP.net projects in two different Visual Studio instances.
Closing one of them fixed the issue.

SQL Server 100% CPU Utilization - One database shows high CPU usage than others

According to this article on sqlserverstudymaterial;

Remember that "%Privileged time" is not based on 100%.It is based on number of processors.If you see 200 for sqlserver.exe and the system has 8 CPU then CPU consumed by sqlserver.exe is 200 out of 800 (only 25%).

If "% Privileged Time" value is more than 30% then it's generally caused by faulty drivers or anti-virus software. In such situations make sure the BIOS and filter drives are up to date and then try disabling the anti-virus software temporarily to see the change.

If "% User Time" is high then there is something consuming of SQL Server. There are several known patterns which can be caused high CPU for processes running in SQL Server including

C Macro definition to determine big endian or little endian machine?

To detect endianness at run time, you have to be able to refer to memory. If you stick to standard C, declarating a variable in memory requires a statement, but returning a value requires an expression. I don't know how to do this in a single macro—this is why gcc has extensions :-)

If you're willing to have a .h file, you can define

static uint32_t endianness = 0xdeadbeef; 
enum endianness { BIG, LITTLE };

#define ENDIANNESS ( *(const char *)&endianness == 0xef ? LITTLE \
                   : *(const char *)&endianness == 0xde ? BIG \
                   : assert(0))

and then you can use the ENDIANNESS macro as you will.

Javascript string/integer comparisons

The alert() wants to display a string, so it will interpret "2">"10" as a string.

Use the following:

var greater = parseInt("2") > parseInt("10");
alert("Is greater than? " + greater);

var less = parseInt("2") < parseInt("10");
alert("Is less than? " + less);

must declare a named package eclipse because this compilation unit is associated to the named module

Reason of the error: Package name left blank while creating a class. This make use of default package. Thus causes this error.

Quick fix:

  1. Create a package eg. helloWorld inside the src folder.
  2. Move helloWorld.java file in that package. Just drag and drop on the package. Error should disappear.

Explanation:

  • My Eclipse version: 2020-09 (4.17.0)
  • My Java version: Java 15, 2020-09-15

Latest version of Eclipse required java11 or above. The module feature is introduced in java9 and onward. It was proposed in 2005 for Java7 but later suspended. Java is object oriented based. And module is the moduler approach which can be seen in language like C. It was harder to implement it, due to which it took long time for the release. Source: Understanding Java 9 Modules

When you create a new project in Eclipse then by default module feature is selected. And in Eclipse-2020-09-R, a pop-up appears which ask for creation of module-info.java file. If you select don't create then module-info.java will not create and your project will free from this issue.

Best practice is while crating project, after giving project name. Click on next button instead of finish. On next page at the bottom it ask for creation of module-info.java file. Select or deselect as per need.

If selected: (by default) click on finish button and give name for module. Now while creating a class don't forget to give package name. Whenever you create a class just give package name. Any name, just don't left it blank.

If deselect: No issue

Using AES encryption in C#

here is a neat and clean code to understand AES 256 algorithm implemented in C# call Encrypt function as encryptedstring = cryptObj.Encrypt(username, "AGARAMUDHALA", "EZHUTHELLAM", "SHA1", 3, "@1B2c3D4e5F6g7H8", 256);

public class Crypt
{
    public string Encrypt(string passtext, string passPhrase, string saltV, string hashstring, int Iterations, string initVect, int keysize)
    {
        string functionReturnValue = null;
        // Convert strings into byte arrays.
        // Let us assume that strings only contain ASCII codes.
        // If strings include Unicode characters, use Unicode, UTF7, or UTF8
        // encoding.
        byte[] initVectorBytes = null;
        initVectorBytes = Encoding.ASCII.GetBytes(initVect);
        byte[] saltValueBytes = null;
        saltValueBytes = Encoding.ASCII.GetBytes(saltV);

        // Convert our plaintext into a byte array.
        // Let us assume that plaintext contains UTF8-encoded characters.
        byte[] plainTextBytes = null;
        plainTextBytes = Encoding.UTF8.GetBytes(passtext);
        // First, we must create a password, from which the key will be derived.
        // This password will be generated from the specified passphrase and
        // salt value. The password will be created using the specified hash
        // algorithm. Password creation can be done in several iterations.
        PasswordDeriveBytes password = default(PasswordDeriveBytes);
        password = new PasswordDeriveBytes(passPhrase, saltValueBytes, hashstring, Iterations);
        // Use the password to generate pseudo-random bytes for the encryption
        // key. Specify the size of the key in bytes (instead of bits).
        byte[] keyBytes = null;
        keyBytes = password.GetBytes(keysize/8);
        // Create uninitialized Rijndael encryption object.
        RijndaelManaged symmetricKey = default(RijndaelManaged);
        symmetricKey = new RijndaelManaged();

        // It is reasonable to set encryption mode to Cipher Block Chaining
        // (CBC). Use default options for other symmetric key parameters.
        symmetricKey.Mode = CipherMode.CBC;
        // Generate encryptor from the existing key bytes and initialization
        // vector. Key size will be defined based on the number of the key
        // bytes.
        ICryptoTransform encryptor = default(ICryptoTransform);
        encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes);

        // Define memory stream which will be used to hold encrypted data.
        MemoryStream memoryStream = default(MemoryStream);
        memoryStream = new MemoryStream();

        // Define cryptographic stream (always use Write mode for encryption).
        CryptoStream cryptoStream = default(CryptoStream);
        cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
        // Start encrypting.
        cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);

        // Finish encrypting.
        cryptoStream.FlushFinalBlock();
        // Convert our encrypted data from a memory stream into a byte array.
        byte[] cipherTextBytes = null;
        cipherTextBytes = memoryStream.ToArray();

        // Close both streams.
        memoryStream.Close();
        cryptoStream.Close();

        // Convert encrypted data into a base64-encoded string.
        string cipherText = null;
        cipherText = Convert.ToBase64String(cipherTextBytes);

        functionReturnValue = cipherText;
        return functionReturnValue;
    }
    public string Decrypt(string cipherText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize)
    {
        string functionReturnValue = null;

        // Convert strings defining encryption key characteristics into byte
        // arrays. Let us assume that strings only contain ASCII codes.
        // If strings include Unicode characters, use Unicode, UTF7, or UTF8
        // encoding.


            byte[] initVectorBytes = null;
            initVectorBytes = Encoding.ASCII.GetBytes(initVector);

            byte[] saltValueBytes = null;
            saltValueBytes = Encoding.ASCII.GetBytes(saltValue);

            // Convert our ciphertext into a byte array.
            byte[] cipherTextBytes = null;
            cipherTextBytes = Convert.FromBase64String(cipherText);

            // First, we must create a password, from which the key will be
            // derived. This password will be generated from the specified
            // passphrase and salt value. The password will be created using
            // the specified hash algorithm. Password creation can be done in
            // several iterations.
            PasswordDeriveBytes password = default(PasswordDeriveBytes);
            password = new PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations);

            // Use the password to generate pseudo-random bytes for the encryption
            // key. Specify the size of the key in bytes (instead of bits).
            byte[] keyBytes = null;
            keyBytes = password.GetBytes(keySize / 8);

            // Create uninitialized Rijndael encryption object.
            RijndaelManaged symmetricKey = default(RijndaelManaged);
            symmetricKey = new RijndaelManaged();

            // It is reasonable to set encryption mode to Cipher Block Chaining
            // (CBC). Use default options for other symmetric key parameters.
            symmetricKey.Mode = CipherMode.CBC;

            // Generate decryptor from the existing key bytes and initialization
            // vector. Key size will be defined based on the number of the key
            // bytes.
            ICryptoTransform decryptor = default(ICryptoTransform);
            decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes);

            // Define memory stream which will be used to hold encrypted data.
            MemoryStream memoryStream = default(MemoryStream);
            memoryStream = new MemoryStream(cipherTextBytes);

            // Define memory stream which will be used to hold encrypted data.
            CryptoStream cryptoStream = default(CryptoStream);
            cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read);

            // Since at this point we don't know what the size of decrypted data
            // will be, allocate the buffer long enough to hold ciphertext;
            // plaintext is never longer than ciphertext.
            byte[] plainTextBytes = null;
            plainTextBytes = new byte[cipherTextBytes.Length + 1];

            // Start decrypting.
            int decryptedByteCount = 0;
            decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);

            // Close both streams.
            memoryStream.Close();
            cryptoStream.Close();

            // Convert decrypted data into a string.
            // Let us assume that the original plaintext string was UTF8-encoded.
            string plainText = null;
            plainText = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);

            // Return decrypted string.
            functionReturnValue = plainText;


        return functionReturnValue;
    }
}

React js change child component's state from parent component

Above answer is partially correct for me, but In my scenario, I want to set the value to a state, because I have used the value to show/toggle a modal. So I have used like below. Hope it will help someone.

class Child extends React.Component {
  state = {
    visible:false
  };

  handleCancel = (e) => {
      e.preventDefault();
      this.setState({ visible: false });
  };

  componentDidMount() {
    this.props.onRef(this)
  }

  componentWillUnmount() {
    this.props.onRef(undefined)
  }

  method() {
    this.setState({ visible: true });
  }

  render() {
    return (<Modal title="My title?" visible={this.state.visible} onCancel={this.handleCancel}>
      {"Content"}
    </Modal>)
  }
}

class Parent extends React.Component {
  onClick = () => {
    this.child.method() // do stuff
  }
  render() {
    return (
      <div>
        <Child onRef={ref => (this.child = ref)} />
        <button onClick={this.onClick}>Child.method()</button>
      </div>
    );
  }
}

Reference - https://github.com/kriasoft/react-starter-kit/issues/909#issuecomment-252969542

case statement in where clause - SQL Server

simply do the select:

Select * From Times
WHERE (StartDate <= @Date) AND (EndDate >= @Date) AND
((@day = 'Monday' AND (Monday = 1))
OR (@day = 'Tuesday' AND (Tuesday = 1))
OR (Wednesday = 1))

Namespace for [DataContract]

First, I add the references to my Model, then I use them in my code. There are two references you should add:

using System.ServiceModel;
using System.Runtime.Serialization;

then, this problem was solved in my program. I hope this answer can help you. Thanks.

How can I access each element of a pair in a pair list?

If you want to use names, try a namedtuple:

from collections import namedtuple

Pair = namedtuple("Pair", ["first", "second"])

pairs = [Pair("a", 1), Pair("b", 2), Pair("c", 3)]

for pair in pairs:
    print("First = {}, second = {}".format(pair.first, pair.second))

Meaning of ${project.basedir} in pom.xml

There are a set of available properties to all Maven projects.

From Introduction to the POM:

project.basedir: The directory that the current project resides in.

This means this points to where your Maven projects resides on your system. It corresponds to the location of the pom.xml file. If your POM is located inside /path/to/project/pom.xml then this property will evaluate to /path/to/project.

Some properties are also inherited from the Super POM, which is the case for project.build.directory. It is the value inside the <project><build><directory> element of the POM. You can get a description of all those values by looking at the Maven model. For project.build.directory, it is:

The directory where all files generated by the build are placed. The default value is target.

This is the directory that will hold every generated file by the build.

Show current assembly instruction in GDB

Setting the following option:

set  disassemble-next-line on
show disassemble-next-line

Will give you results that look like this:

(gdb) stepi
0x000002ce in ResetISR () at startup_gcc.c:245
245 {
   0x000002cc <ResetISR+0>: 80 b5   push    {r7, lr}
=> 0x000002ce <ResetISR+2>: 82 b0   sub sp, #8
   0x000002d0 <ResetISR+4>: 00 af   add r7, sp, #0
(gdb) stepi
0x000002d0  245 {
   0x000002cc <ResetISR+0>: 80 b5   push    {r7, lr}
   0x000002ce <ResetISR+2>: 82 b0   sub sp, #8
=> 0x000002d0 <ResetISR+4>: 00 af   add r7, sp, #0

How to replace blank (null ) values with 0 for all records?

I would change the SQL statement above to be more generic. Using wildcards is never a bad idea when it comes to mass population to avoid nulls.

Try this:

Update Table Set * = 0 Where * Is Null; 

What is considered a good response time for a dynamic, personalized web application?

I think you will find that if your web app is performing a complex operation then provided feedback is given to the user, they won't mind (too much).

For example: Loading Google Mail.

Add element to a JSON file?

You can do this.

data[0]['f'] = var

Is it possible to select the last n items with nth-child?

Because of the definition of the semantics of nth-child, I don't see how this is possible without including the length of the list of elements involved. The point of the semantics is to allow segregation of a bunch of child elements into repeating groups (edit - thanks BoltClock) or into a first part of some fixed length, followed by "the rest". You sort-of want the opposite of that, which is what nth-last-child gives you.

How can I count the number of matches for a regex?

matcher.find() does not find all matches, only the next match.

Solution for Java 9+

long matches = matcher.results().count();

Solution for Java 8 and older

You'll have to do the following. (Starting from Java 9, there is a nicer solution)

int count = 0;
while (matcher.find())
    count++;

Btw, matcher.groupCount() is something completely different.

Complete example:

import java.util.regex.*;

class Test {
    public static void main(String[] args) {
        String hello = "HelloxxxHelloxxxHello";
        Pattern pattern = Pattern.compile("Hello");
        Matcher matcher = pattern.matcher(hello);

        int count = 0;
        while (matcher.find())
            count++;

        System.out.println(count);    // prints 3
    }
}

Handling overlapping matches

When counting matches of aa in aaaa the above snippet will give you 2.

aaaa
aa
  aa

To get 3 matches, i.e. this behavior:

aaaa
aa
 aa
  aa

You have to search for a match at index <start of last match> + 1 as follows:

String hello = "aaaa";
Pattern pattern = Pattern.compile("aa");
Matcher matcher = pattern.matcher(hello);

int count = 0;
int i = 0;
while (matcher.find(i)) {
    count++;
    i = matcher.start() + 1;
}

System.out.println(count);    // prints 3

Spring data JPA query with parameter properties

@Autowired
private EntityManager entityManager;

@RequestMapping("/authors/{fname}/{lname}")
    public List actionAutherMulti(@PathVariable("fname") String fname, @PathVariable("lname") String lname) {
        return entityManager.createQuery("select A from Auther A WHERE A.firstName = ?1 AND A.lastName=?2")
                .setParameter(1, fname)
                .setParameter(2, lname)
                .getResultList();
    }

Selected value for JSP drop down using JSTL

If you don't mind using jQuery you can use the code bellow:

    <script>
     $(document).ready(function(){
           $("#department").val("${requestScope.selectedDepartment}").attr('selected', 'selected');
     });
     </script>


    <select id="department" name="department">
      <c:forEach var="item" items="${dept}">
        <option value="${item.key}">${item.value}</option>
      </c:forEach>
    </select>

In the your Servlet add the following:

        request.setAttribute("selectedDepartment", YOUR_SELECTED_DEPARTMENT );

Attach IntelliJ IDEA debugger to a running Java process

in AndroidStudio or idea

  1. Config the application will be debug, open Edit Configurations

add "VM Options" Config “-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005” remember "address"

enter image description here

  1. Config Remote Debugger if not exits, Click + to add

specify "Port" same as in Step 1 "address" enter image description here

String formatting in Python 3

I like this approach

my_hash = {}
my_hash["goals"] = 3 #to show number
my_hash["penalties"] = "5" #to show string
print("I scored %(goals)d goals and took %(penalties)s penalties" % my_hash)

Note the appended d and s to the brackets respectively.

output will be:

I scored 3 goals and took 5 penalties

Laravel Migration Error: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes

In order to avoid changing anything in your code, simply update your MySQL server to at least 5.7.7

Reference this for more info : https://laravel-news.com/laravel-5-4-key-too-long-error

log4j vs logback

In the logging world there are Facades (like Apache Commons Logging, slf4j or even the Log4j 2.0 API) and implementations (Log4j 1 + 2, java.util.logging, TinyLog, Logback).

Basically you should replace your selfmade wrapper with slf4j IF and only IF you are not happy with it for some reason. While Apache Commons Logging is not really providing a modern API, slf4j and the new Log4j 2 facade is providing that. Given that quite a bunch of apps use slf4j as a wrapper it might make sense to use that.

slf4j gives a number of nice API sugar, like this example from slf4j docs:

logger.debug("Temperature set to {}. Old temperature was {}.", t, oldT);

It's variable substitution. This is also supported by Log4j 2.

However you need to be aware that slf4j is developed by QOS who also maintain logback. Log4j 2.0 is baked in the Apache Software Foundation. In the past three years a vibrant and active community has grown there again. If you appreciate Open Source as it is done by the Apache Software Foundation with all its guarantees you might reconsider using slf4j in favor to use Log4j 2 directly.

Please note:

In the past log4j 1 was not actively maintained while Logback was. But today things are different. Log4j 2 is actively maintained and releases on almost regular schedule. It also includes lot of modern features and -imho- makes a couple of things better than Logback. This is sometimes just a matter of taste and you should draw your own conclusions.

I wrote a quick overview on the new Features of Log4j 2.0: http://www.grobmeier.de/the-new-log4j-2-0-05122012.html

When reading you will see that Log4j 2 was inspired by Logback but also by other logging frameworks. But the code base is different; it shares almost nothing with Log4j 1 and zero with Logback. This lead to some improvements like in example Log4j 2 operates with bytestreams instead of Strings under the hood. Also it doesn't loose events while reconfiguring.

Log4j 2 can log with higher speed than other frameworks I know: http://www.grobmeier.de/log4j-2-performance-close-to-insane-20072013.html

And still the user community seems to be much bigger than Logbacks: http://www.grobmeier.de/apache-log4j-is-the-leading-logging-framework-06082013.html

That all said the best idea is you choose the logging frameworks which just fits best to what you want to achieve. I would not switch a full framework if I would disable logging in production environment and just perform basic logging in my app. However if you do a bit more with logging just look at the features which are provided by the frameworks and their developers. While you get commercial support for Logback through QOS (i heard) there is currently no commercial support for Log4j 2. On the other hand if you need to do audit logging and need high performance provided by the async appenders it makes a lot of sense to check log4j 2.

Please note despite all comfort they provide, facades always eat a little performance. It's maybe not affecting you at all, but if you are on low resources you may need to save everything you can have.

Without knowing you requirements better it is almost impossible to give a recommendation. Just: don't switch just because a lot of people switch. Switch only because you see value of it. And the argumentation that log4j is dead doesn't count anymore. It's alive, and it's hot.

DISCLAIMER: I am currently VP, Apache Logging Services and involved in log4j as well.

How to use onClick with divs in React.js

This works

var Box = React.createClass({
    getInitialState: function() {
        return {
            color: 'white'
        };
    },

    changeColor: function() {
        var newColor = this.state.color == 'white' ? 'black' : 'white';
        this.setState({ color: newColor });
    },

    render: function() {
        return (
            <div>
                <div
                    className='box'
                    style={{background:this.state.color}}
                    onClick={this.changeColor}
                >
                    In here already
                </div>
            </div>
        );
    }
});

ReactDOM.render(<Box />, document.getElementById('div1'));
ReactDOM.render(<Box />, document.getElementById('div2'));
ReactDOM.render(<Box />, document.getElementById('div3'));

and in your css, delete the styles you have and put this

.box {
  width: 200px;
  height: 200px;
  border: 1px solid black;
  float: left;
}

You have to style the actual div you are calling onClick on. Give the div a className and then style it. Also remember to remove this block where you are rendering App into the dom, App is not defined

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

PHP Get name of current directory

To get the names of current directory we can use getcwd() or dirname(__FILE__) but getcwd() and dirname(__FILE__) are not synonymous. They do exactly what their names are. If your code is running by referring a class in another file which exists in some other directory then these both methods will return different results.

For example if I am calling a class, from where these two functions are invoked and the class exists in some /controller/goodclass.php from /index.php then getcwd() will return '/ and dirname(__FILE__) will return /controller.

find: missing argument to -exec

You need to do some escaping I think.

find /home/me/download/ -type f -name "*.rm" -exec ffmpeg -i {} \-sameq {}.mp3 \&\& rm {}\;

Pause in Python

If you type

input("")

It will wait for them to press any button then it will continue. Also you can put text between the quotes.

How can I remove non-ASCII characters but leave periods and spaces using Python?

If you want printable ascii characters you probably should correct your code to:

if ord(char) < 32 or ord(char) > 126: return ''

this is equivalent, to string.printable (answer from @jterrace), except for the absence of returns and tabs ('\t','\n','\x0b','\x0c' and '\r') but doesnt correspond to the range on your question

Definitive way to trigger keypress events with jQuery

If you're using jQuery UI too, you can do like this:

var e = jQuery.Event("keypress");
e.keyCode = $.ui.keyCode.ENTER;
$("input").trigger(e);

Can I specify multiple users for myself in .gitconfig?

If you do not want to have a default email address (email address links to a github user), you can configure that you want to be asked. How you can do that depends on the version of git you use, see below.

The (intended) drawback is that you have to configure your email address (and your name) once for every repository. So, you cannot forget to do it.

Version < 2.7.0

[user]
    name = Your name
    email = "(none)"

in your global configuration ~/.gitconfig as stated in a comment by Dan Aloni in Orr Sella's blog post. When trying to do the first commit in a repository, git fails with the nice message:

*** Please tell me who you are.

Run

  git config --global user.email "[email protected]"
  git config --global user.name "Your Name"

to set your account's default identity.
Omit --global to set the identity only in this repository.

fatal: unable to auto-detect email address (got '(none)')

The name is taken from the global config when the email address is set locally (the message is not perfectly accurate).

2.7.0 = Version < 2.8.0

The behaviour in versions < 2.7.0 was not intended and fixed with 2.7.0. You can still use a pre-commit hook as described in Orr Sella's blog post. This solution works also for other versions, but the other solutions not for this version.

Version = 2.8.0

Dan Aloni added an option to achieve that behaviour (see release notes). Use it with:

[user]
    useConfigOnly = true

To make it work you may not give a name or email address in the global config. Then, at the first commit, you get an error message

fatal: user.useConfigOnly set but no name given

So the message is not very instructive, but since you set the option explicitly, you should know what to do. In contrast to the solution of versions < 2.7.0, you always have to set both name and email manually.

Best way to parseDouble with comma as decimal separator?

You can use this (the French locale has , for decimal separator)

NumberFormat nf = NumberFormat.getInstance(Locale.FRANCE);
nf.parse(p);

Or you can use java.text.DecimalFormat and set the appropriate symbols:

DecimalFormat df = new DecimalFormat();
DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setDecimalSeparator(',');
symbols.setGroupingSeparator(' ');
df.setDecimalFormatSymbols(symbols);
df.parse(p);

How do you clone an Array of Objects in Javascript?

For cloning the objects as well I was just going to suggest ECMAScript 6 reduce():

const newArray=myArray.reduce((array, element)=>array.push(Object.assign({}, element)), []);

But frankly I like the answer of @dinodsaurus even better. I'm just putting this version here as another option, but personally I'll be using map() as suggested by @dinodsaurus .

Filter Excel pivot table using VBA

Field.CurrentPage only works for Filter fields (also called page fields).
If you want to filter a row/column field, you have to cycle through the individual items, like so:

Sub FilterPivotField(Field As PivotField, Value)
    Application.ScreenUpdating = False
    With Field
        If .Orientation = xlPageField Then
            .CurrentPage = Value
        ElseIf .Orientation = xlRowField Or .Orientation = xlColumnField Then
            Dim i As Long
            On Error Resume Next ' Needed to avoid getting errors when manipulating PivotItems that were deleted from the data source.
            ' Set first item to Visible to avoid getting no visible items while working
            .PivotItems(1).Visible = True
            For i = 2 To Field.PivotItems.Count
                If .PivotItems(i).Name = Value Then _
                    .PivotItems(i).Visible = True Else _
                    .PivotItems(i).Visible = False
            Next i
            If .PivotItems(1).Name = Value Then _
                .PivotItems(1).Visible = True Else _
                .PivotItems(1).Visible = False
        End If
    End With
    Application.ScreenUpdating = True
End Sub

Then, you would just call:

FilterPivotField ActiveSheet.PivotTables("PivotTable2").PivotFields("SavedFamilyCode"), "K123223"

Naturally, this gets slower the more there are individual different items in the field. You can also use SourceName instead of Name if that suits your needs better.

Python 3 ImportError: No module named 'ConfigParser'

For me the following command worked:

sudo python3 -m pip install mysql-connector

Stratified Train/Test-split in scikit-learn

Updating @tangy answer from above to the current version of scikit-learn: 0.23.2 (StratifiedShuffleSplit documentation).

from sklearn.model_selection import StratifiedShuffleSplit

n_splits = 1  # We only want a single split in this case
sss = StratifiedShuffleSplit(n_splits=n_splits, test_size=0.25, random_state=0)

for train_index, test_index in sss.split(X, y):
    X_train, X_test = X[train_index], X[test_index]
    y_train, y_test = y[train_index], y[test_index]

CSS: how to get scrollbars for div inside container of fixed height

setting the overflow should take care of it, but you need to set the height of Content also. If the height attribute is not set, the div will grow vertically as tall as it needs to, and scrollbars wont be needed.

See Example: http://jsfiddle.net/ftkbL/1/

How do I round a float upwards to the nearest int in C#?

Off the top of my head:

float fl = 0.678;
int rounded_f = (int)(fl+0.5f);

How do I purge a linux mail box with huge number of emails?

If you're using cyrus/sasl/imap on your mailserver, then one fast and efficient way to purge everything in a mailbox that is older then number of days specified is to use cyrus/imap ipurge command. For example, here is an example removing everything (be carefull!!), older then 30 days from user vleo. Notice, that you must be logged in as cyrus (imap mail administrator) user:

[cyrus@mailserver ~]$ /usr/lib/cyrus-imapd/ipurge -f -d 30 user.vleo Working on user.vleo... total messages 4 total bytes 113183 Deleted messages 0 Deleted bytes 0 Remaining messages 4 Remaining bytes 113183

Portable way to check if directory exists [Windows/Linux, C]

stat() works on Linux., UNIX and Windows as well:

#include <sys/types.h>
#include <sys/stat.h>

struct stat info;

if( stat( pathname, &info ) != 0 )
    printf( "cannot access %s\n", pathname );
else if( info.st_mode & S_IFDIR )  // S_ISDIR() doesn't exist on my windows 
    printf( "%s is a directory\n", pathname );
else
    printf( "%s is no directory\n", pathname );

Is it possible to change the radio button icon in an android radio button group

Yes that's possible you have to define your own style for radio buttons, at res/values/styles.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="CustomTheme" parent="android:Theme">
   <item name="android:radioButtonStyle">@style/RadioButton</item>
</style>
<style name="RadioButton" parent="@android:style/Widget.CompoundButton.RadioButton">
   <item name="android:button">@drawable/radio</item>
</style>
</resources>

'radio' here should be a stateful drawable, radio.xml:

    <?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_window_focused="false"
        android:drawable="@drawable/radio_hover" />
    <item android:state_checked="false" android:state_window_focused="false"
        android:drawable="@drawable/radio_normal" />
    <item android:state_checked="true" android:state_pressed="true"
        android:drawable="@drawable/radio_active" />
    <item android:state_checked="false" android:state_pressed="true"
        android:drawable="@drawable/radio_active" />
    <item android:state_checked="true" android:state_focused="true"
        android:drawable="@drawable/radio_hover" />
    <item android:state_checked="false" android:state_focused="true"
        android:drawable="@drawable/radio_normal_off" />
    <item android:state_checked="false" android:drawable="@drawable/radio_normal" />
    <item android:state_checked="true" android:drawable="@drawable/radio_hover" />
    </selector>

Then just apply the Custom theme either to whole app or to activities of your choice.

For more info about themes and styles look at http://brainflush.wordpress.com/2009/03/15/understanding-android-themes-and-styles/ that is good guide.

How do I get a background location update every n minutes in my iOS application?

I used xs2bush's method of getting an interval (using timeIntervalSinceDate) and expanded on it a little bit. I wanted to make sure that I was getting the required accuracy that I needed and also that I was not running down the battery by keeping the gps radio on more than necessary.

I keep location running continuously with the following settings:

locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers;
locationManager.distanceFilter = 5;

this is a relatively low drain on the battery. When I'm ready to get my next periodic location reading, I first check to see if the location is within my desired accuracy, if it is, I then use the location. If it's not, then I increase the accuracy with this:

locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
locationManager.distanceFilter = 0;

get my location and then once I have the location I turn the accuracy back down again to minimize the drain on the battery. I have written a full working sample of this and also I have written the source for the server side code to collect the location data, store it to a database and allow users to view gps data in real time or retrieve and view previously stored routes. I have clients for iOS, android, windows phone and java me. All clients are natively written and they all work properly in the background. The project is MIT licensed.

The iOS project is targeted for iOS 6 using a base SDK of iOS 7. You can get the code here.

Please file an issue on github if you see any problems with it. Thanks.

MySQL's now() +1 day

INSERT INTO `table` ( `data` , `date` ) VALUES('".$data."',NOW()+INTERVAL 1 DAY);

How to change the href for a hyperlink using jQuery

With jQuery 1.6 and above you should use:

$("a").prop("href", "http://www.jakcms.com")

The difference between prop and attr is that attr grabs the HTML attribute whereas prop grabs the DOM property.

You can find more details in this post: .prop() vs .attr()

Pandas dataframe groupby plot

Simple plot,

you can use:

df.plot(x='Date',y='adj_close')

Or you can set the index to be Date beforehand, then it's easy to plot the column you want:

df.set_index('Date', inplace=True)
df['adj_close'].plot()

If you want a chart with one series by ticker on it

You need to groupby before:

df.set_index('Date', inplace=True)
df.groupby('ticker')['adj_close'].plot(legend=True)

enter image description here


If you want a chart with individual subplots:

grouped = df.groupby('ticker')

ncols=2
nrows = int(np.ceil(grouped.ngroups/ncols))

fig, axes = plt.subplots(nrows=nrows, ncols=ncols, figsize=(12,4), sharey=True)

for (key, ax) in zip(grouped.groups.keys(), axes.flatten()):
    grouped.get_group(key).plot(ax=ax)

ax.legend()
plt.show()

enter image description here

How to validate date with format "mm/dd/yyyy" in JavaScript?

  1. Javascript

    function validateDate(date) {
        try {
            new Date(date).toISOString();
            return true;
        } catch (e) { 
            return false; 
        }
    }
    
  2. JQuery

    $.fn.validateDate = function() {
        try {
            new Date($(this[0]).val()).toISOString();
            return true;
        } catch (e) { 
            return false; 
        }
    }
    

returns true for a valid date string.

Pass parameters in setInterval function

You can use an anonymous function;

setInterval(function() { funca(10,3); },500);

How to upgrade Git on Windows to the latest version?

Just run:

$ git update-git-for-windows

Identify if a string is a number

All the Answers are Useful. But while searching for a solution where the Numeric value is 12 digits or more (in my case), then while debugging, I found the following solution useful :

double tempInt = 0;
bool result = double.TryParse("Your_12_Digit_Or_more_StringValue", out tempInt);

Th result variable will give you true or false.

Does :before not work on img elements?

Try this code

.button:after {
    content: ""
    position: absolute
    width: 70px
    background-image: url('../../images/frontapp/mid-icon.svg')
    display: inline-block
    background-size: contain
    background-repeat: no-repeat
    right: 0
    bottom: 0
}

How to use setInterval and clearInterval?

Side note – if you want to use separate functions to set & clear interval, the interval variable have to be accessible for all of them, in 'relative global', or 'one level up' scope:

var interval = null;    

function startStuff(func, time) {
    interval = setInterval(func, time);
}

function stopStuff() {
    clearInterval(interval);
}

How to fix "'System.AggregateException' occurred in mscorlib.dll"

As the message says, you have a task which threw an unhandled exception.

Turn on Break on All Exceptions (Debug, Exceptions) and rerun the program.
This will show you the original exception when it was thrown in the first place.


(comment appended): In VS2015 (or above). Select Debug > Options > Debugging > General and unselect the "Enable Just My Code" option.

T-SQL Cast versus Convert

CONVERT is SQL Server specific, CAST is ANSI.

CONVERT is more flexible in that you can format dates etc. Other than that, they are pretty much the same. If you don't care about the extended features, use CAST.

EDIT:

As noted by @beruic and @C-F in the comments below, there is possible loss of precision when an implicit conversion is used (that is one where you use neither CAST nor CONVERT). For further information, see CAST and CONVERT and in particular this graphic: SQL Server Data Type Conversion Chart. With this extra information, the original advice still remains the same. Use CAST where possible.

How to see which flags -march=native will activate?

I'm going to throw my two cents into this question and suggest a slightly more verbose extension of elias's answer. As of gcc 4.6, running of gcc -march=native -v -E - < /dev/null emits an increasing amount of spam in the form of superfluous -mno-* flags. The following will strip these:

gcc -march=native -v -E - < /dev/null 2>&1 | grep cc1 | perl -pe 's/ -mno-\S+//g; s/^.* - //g;'

However, I have only verified the correctness of this on two different CPUs (an Intel Core2 and AMD Phenom), so I suggest also running the following script to be sure that all of these -mno-* flags can be safely stripped.

2021 EDIT: There are indeed machines where -march=native uses a particular -march value, but must disable some implied ISAs (Instruction Set Architecture) with -mno-*.

#!/bin/bash

gcc_cmd="gcc"

# Optionally supply path to gcc as first argument
if (($#)); then
    gcc_cmd="$1"
fi

with_mno=$(
    "${gcc_cmd}" -march=native -mtune=native -v -E - < /dev/null 2>&1 |
    grep cc1 |
    perl -pe 's/^.* - //g;'
)
without_mno=$(echo "${with_mno}" | perl -pe 's/ -mno-\S+//g;')

"${gcc_cmd}" ${with_mno}    -dM -E - < /dev/null > /tmp/gcctest.a.$$
"${gcc_cmd}" ${without_mno} -dM -E - < /dev/null > /tmp/gcctest.b.$$

if diff -u /tmp/gcctest.{a,b}.$$; then
    echo "Safe to strip -mno-* options."
else
    echo
    echo "WARNING! Some -mno-* options are needed!"
    exit 1
fi

rm /tmp/gcctest.{a,b}.$$

I haven't found a difference between gcc -march=native -v -E - < /dev/null and gcc -march=native -### -E - < /dev/null other than some parameters being quoted -- and parameters that contain no special characters, so I'm not sure under what circumstances this makes any real difference.

Finally, note that --march=native was introduced in gcc 4.2, prior to which it is just an unrecognized argument.

How to add values in a variable in Unix shell scripting?

In ksh ,bash ,sh:

$ count7=0                     
$ count1=5
$ 
$ (( count7 += count1 ))
$ echo $count7
$ 5

How to modify PATH for Homebrew?

open your /etc/paths file, put /usr/local/bin on top of /usr/bin

$ sudo vi /etc/paths
/usr/local/bin
/usr/local/sbin
/usr/bin
/bin
/usr/sbin
/sbin

and Restart the terminal, @mmel

Improve subplot size/spacing with many subplots in matplotlib

I found that subplots_adjust(hspace = 0.001) is what ended up working for me. When I use space = None, there is still white space between each plot. Setting it to something very close to zero however seems to force them to line up. What I've uploaded here isn't the most elegant piece of code, but you can see how the hspace works.

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.ticker as tic

fig = plt.figure()

x = np.arange(100)
y = 3.*np.sin(x*2.*np.pi/100.)

for i in range(5):
    temp = 510 + i
    ax = plt.subplot(temp)
    plt.plot(x,y)
    plt.subplots_adjust(hspace = .001)
    temp = tic.MaxNLocator(3)
    ax.yaxis.set_major_locator(temp)
    ax.set_xticklabels(())
    ax.title.set_visible(False)

plt.show()

enter image description here

Can I set text box to readonly when using Html.TextBoxFor?

Updated for modern versions of .NET per @1c1cle's suggestion in a comment:

<%= Html.TextBoxFor(model => Model.SomeFieldName, new {{"readonly", "true"}}) %>

Do realize that this is not a "secure" way to do this as somebody can inject javascript to change this.

Something to be aware of is that if you set that readonly value to false, you actually won't see any change in behavior! So if you need to drive this based on a variable, you cannot simply plug that variable in there. Instead you need to use conditional logic to simply not pass that readonly attribute in.

Here is an untested suggestion for how to do this (if there's a problem with this, you can always do an if/else):

<%= Html.TextBoxFor(model => Model.SomeFieldName, shouldBeReadOnlyBoolean ? new {{"readonly", "true"}} : null) %>

How do I get the logfile from an Android device?

Often I get the error "logcat read: Invalid argument". I had to clear the log, before reading from the log.

I do like this:

prompt> cd ~/Desktop
prompt> adb logcat -c
prompt> adb logcat | tee log.txt

java.lang.ClassNotFoundException: com.sun.jersey.spi.container.servlet.ServletContainer

In pom.xml file we need to add

<dependency>
    <groupId>com.sun.jersey</groupId>
    <artifactId>jersey-core</artifactId>
    <version>1.8</version>
</dependency>

See last changes in svn

svn log - I'm sure WebSVN has some feature for that too.

The "View Log" link near the center-top of the WebSVN overview shows the svn-log. However, the user-interface isn't exactly brilliant; I much prefer TortoiseSVN's log viewer.

Iterate through a HashMap

Iterate through the entrySet() like so:

public static void printMap(Map mp) {
    Iterator it = mp.entrySet().iterator();
    while (it.hasNext()) {
        Map.Entry pair = (Map.Entry)it.next();
        System.out.println(pair.getKey() + " = " + pair.getValue());
        it.remove(); // avoids a ConcurrentModificationException
    }
}

Read more about Map.

Add external libraries to CMakeList.txt c++

I would start with upgrade of CMAKE version.

You can use INCLUDE_DIRECTORIES for header location and LINK_DIRECTORIES + TARGET_LINK_LIBRARIES for libraries

INCLUDE_DIRECTORIES(your/header/dir)
LINK_DIRECTORIES(your/library/dir)
rosbuild_add_executable(kinectueye src/kinect_ueye.cpp)
TARGET_LINK_LIBRARIES(kinectueye lib1 lib2 lib2 ...)

note that lib1 is expanded to liblib1.so (on Linux), so use ln to create appropriate links in case you do not have them

Docker: adding a file from a parent directory

The solution for those who use composer is to use a volume pointing to the parent folder:

#docker-composer.yml

foo:
  build: foo
  volumes:
    - ./:/src/:ro

But I'm pretty sure the can be done playing with volumes in Dockerfile.

How to check if a char is equal to an empty space?

To compare character you use the == operator:

if (c == ' ')

Deleting a pointer in C++

int value, *ptr;

value = 8;
ptr = &value;
// ptr points to value, which lives on a stack frame.
// you are not responsible for managing its lifetime.

ptr = new int;
delete ptr;
// yes this is the normal way to manage the lifetime of
// dynamically allocated memory, you new'ed it, you delete it.

ptr = nullptr;
delete ptr;
// this is illogical, essentially you are saying delete nothing.

Android: Storing username and password?

Most Android and iPhone apps I have seen use an initial screen or dialog box to ask for credentials. I think it is cumbersome for the user to have to re-enter their name/password often, so storing that info makes sense from a usability perspective.

The advice from the (Android dev guide) is:

In general, we recommend minimizing the frequency of asking for user credentials -- to make phishing attacks more conspicuous, and less likely to be successful. Instead use an authorization token and refresh it.

Where possible, username and password should not be stored on the device. Instead, perform initial authentication using the username and password supplied by the user, and then use a short-lived, service-specific authorization token.

Using the AccountManger is the best option for storing credentials. The SampleSyncAdapter provides an example of how to use it.

If this is not an option to you for some reason, you can fall back to persisting credentials using the Preferences mechanism. Other applications won't be able to access your preferences, so the user's information is not easily exposed.

Node.js - Find home directory in platform agnostic way

Well, it would be more accurate to rely on the feature and not a variable value. Especially as there are 2 possible variables for Windows.

function getUserHome() {
  return process.env.HOME || process.env.USERPROFILE;
}

EDIT: as mentioned in a more recent answer, https://stackoverflow.com/a/32556337/103396 is the right way to go (require('os').homedir()).

How to open existing project in Eclipse

Right click in navigator-Import-existing project..-select the base directory of your project

www-data permissions?

sudo chown -R yourname:www-data cake

then

sudo chmod -R g+s cake

First command changes owner and group.

Second command adds s attribute which will keep new files and directories within cake having the same group permissions.

jQuery .slideRight effect

If you're willing to include the jQuery UI library, in addition to jQuery itself, then you can simply use hide(), with additional arguments, as follows:

$(document).ready(
    function(){
        $('#slider').click(
            function(){
                $(this).hide('slide',{direction:'right'},1000);

            });
    });

JS Fiddle demo.


Without using jQuery UI, you could achieve your aim just using animate():

$(document).ready(
    function(){
        $('#slider').click(
            function(){
                $(this)
                    .animate(
                        {
                            'margin-left':'1000px'
                            // to move it towards the right and, probably, off-screen.
                        },1000,
                        function(){
                            $(this).slideUp('fast');
                            // once it's finished moving to the right, just 
                            // removes the the element from the display, you could use
                            // `remove()` instead, or whatever.
                        }
                        );

            });
    });

JS Fiddle demo

If you do choose to use jQuery UI, then I'd recommend linking to the Google-hosted code, at: https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.6/jquery-ui.min.js

Graphviz's executables are not found (Python 3.4)

On jupyter(ipython) notebook with anaconda in win10 I solved the problem by conda install graphviz after I had installed graphviz by pip install graphviz

Android: How to add R.raw to project?

Try putting a + before R.xyz. That should start showing additional folders, e.g.:

+ R.raw.beep.mp3

How to capitalize the first letter of text in a TextView in an Android Application

StringBuilder sb = new StringBuilder(name);
sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));  
return sb.toString();

Illegal Escape Character "\"

I think ("\") may be causing the problem because \ is the escape character. change it to ("\\")

ADB not recognising Nexus 4 under Windows 7

It was a driver missing problem with me. I had enabled the USB debugging, tried changing the USB cable, tried reinstalling the Google USB drivers, but nothing came to my rescue.

Then ultimately I downloaded the device drivers as suggested here.

To make sure whether you have a device driver problem, go to:

  1. Computer->right click
  2. Manage
  3. Device Manager

And see if you have your Nexus shown as an "Android device" or as a device in "Others".

If it shows in "Others", your problem should be resolved by downloading & extracting this and then following these steps:

  1. Right click on your device after finding it in Device Manager as per the above mentioned three steps.
  2. Say Update driver software.
  3. Say Browse My computer for driver software
  4. Pinpoint it to the location where you had downloaded the drivers from the above link.

Finally, your device will show up as follows:

Computer Management Screenshot

As soon as you do this, a popup will show up on your device asking for permission to debug. Once you accept, you are ready!

Fixed header table with horizontal scrollbar and vertical scrollbar on

working example in jsFiddle

This can be achieved using div. It can be done with table too. But i always prefer div.

<body id="doc-body" style="width: 100%; height: 100%; overflow: hidden; position: fixed" onload="InitApp()"> 
    <div>
        <!--If you don't need header background color you don't need this div.-->
        <div id="div-header-hack" style="height: 20px; position: absolute; background-color: gray"></div>

        <div id="div-header" style="position: absolute; top: 0px; overflow: hidden; height: 20px; background-color: gray">                
        </div>

        <div id="div-item" style="position: absolute; top: 20px; overflow: auto" onscroll="ScrollHeader()">                
        </div>
    </div>
</body>

Javascript:
please refer jsFiddle for this part. Else this answer becomes very lengthy.

Permutation of array

Here is how you can print all permutations in 10 lines of code:

public class Permute{
    static void permute(java.util.List<Integer> arr, int k){
        for(int i = k; i < arr.size(); i++){
            java.util.Collections.swap(arr, i, k);
            permute(arr, k+1);
            java.util.Collections.swap(arr, k, i);
        }
        if (k == arr.size() -1){
            System.out.println(java.util.Arrays.toString(arr.toArray()));
        }
    }
    public static void main(String[] args){
        Permute.permute(java.util.Arrays.asList(3,4,6,2,1), 0);
    }
}

You take first element of an array (k=0) and exchange it with any element (i) of the array. Then you recursively apply permutation on array starting with second element. This way you get all permutations starting with i-th element. The tricky part is that after recursive call you must swap i-th element with first element back, otherwise you could get repeated values at the first spot. By swapping it back we restore order of elements (basically you do backtracking).

Iterators and Extension to the case of repeated values

The drawback of previous algorithm is that it is recursive, and does not play nicely with iterators. Another issue is that if you allow repeated elements in your input, then it won't work as is.

For example, given input [3,3,4,4] all possible permutations (without repetitions) are

[3, 3, 4, 4]
[3, 4, 3, 4]
[3, 4, 4, 3]
[4, 3, 3, 4]
[4, 3, 4, 3]
[4, 4, 3, 3]

(if you simply apply permute function from above you will get [3,3,4,4] four times, and this is not what you naturally want to see in this case; and the number of such permutations is 4!/(2!*2!)=6)

It is possible to modify the above algorithm to handle this case, but it won't look nice. Luckily, there is a better algorithm (I found it here) which handles repeated values and is not recursive.

First note, that permutation of array of any objects can be reduced to permutations of integers by enumerating them in any order.

To get permutations of an integer array, you start with an array sorted in ascending order. You 'goal' is to make it descending. To generate next permutation you are trying to find the first index from the bottom where sequence fails to be descending, and improves value in that index while switching order of the rest of the tail from descending to ascending in this case.

Here is the core of the algorithm:

//ind is an array of integers
for(int tail = ind.length - 1;tail > 0;tail--){
    if (ind[tail - 1] < ind[tail]){//still increasing

        //find last element which does not exceed ind[tail-1]
        int s = ind.length - 1;
        while(ind[tail-1] >= ind[s])
            s--;

        swap(ind, tail-1, s);

        //reverse order of elements in the tail
        for(int i = tail, j = ind.length - 1; i < j; i++, j--){
            swap(ind, i, j);
        }
        break;
    }
}

Here is the full code of iterator. Constructor accepts an array of objects, and maps them into an array of integers using HashMap.

import java.lang.reflect.Array;
import java.util.*;
class Permutations<E> implements  Iterator<E[]>{

    private E[] arr;
    private int[] ind;
    private boolean has_next;

    public E[] output;//next() returns this array, make it public

    Permutations(E[] arr){
        this.arr = arr.clone();
        ind = new int[arr.length];
        //convert an array of any elements into array of integers - first occurrence is used to enumerate
        Map<E, Integer> hm = new HashMap<E, Integer>();
        for(int i = 0; i < arr.length; i++){
            Integer n = hm.get(arr[i]);
            if (n == null){
                hm.put(arr[i], i);
                n = i;
            }
            ind[i] = n.intValue();
        }
        Arrays.sort(ind);//start with ascending sequence of integers


        //output = new E[arr.length]; <-- cannot do in Java with generics, so use reflection
        output = (E[]) Array.newInstance(arr.getClass().getComponentType(), arr.length);
        has_next = true;
    }

    public boolean hasNext() {
        return has_next;
    }

    /**
     * Computes next permutations. Same array instance is returned every time!
     * @return
     */
    public E[] next() {
        if (!has_next)
            throw new NoSuchElementException();

        for(int i = 0; i < ind.length; i++){
            output[i] = arr[ind[i]];
        }


        //get next permutation
        has_next = false;
        for(int tail = ind.length - 1;tail > 0;tail--){
            if (ind[tail - 1] < ind[tail]){//still increasing

                //find last element which does not exceed ind[tail-1]
                int s = ind.length - 1;
                while(ind[tail-1] >= ind[s])
                    s--;

                swap(ind, tail-1, s);

                //reverse order of elements in the tail
                for(int i = tail, j = ind.length - 1; i < j; i++, j--){
                    swap(ind, i, j);
                }
                has_next = true;
                break;
            }

        }
        return output;
    }

    private void swap(int[] arr, int i, int j){
        int t = arr[i];
        arr[i] = arr[j];
        arr[j] = t;
    }

    public void remove() {

    }
}

Usage/test:

    TCMath.Permutations<Integer> perm = new TCMath.Permutations<Integer>(new Integer[]{3,3,4,4,4,5,5});
    int count = 0;
    while(perm.hasNext()){
        System.out.println(Arrays.toString(perm.next()));
        count++;
    }
    System.out.println("total: " + count);

Prints out all 7!/(2!*3!*2!)=210 permutations.

Modify request parameter with servlet filter

As you've noted HttpServletRequest does not have a setParameter method. This is deliberate, since the class represents the request as it came from the client, and modifying the parameter would not represent that.

One solution is to use the HttpServletRequestWrapper class, which allows you to wrap one request with another. You can subclass that, and override the getParameter method to return your sanitized value. You can then pass that wrapped request to chain.doFilter instead of the original request.

It's a bit ugly, but that's what the servlet API says you should do. If you try to pass anything else to doFilter, some servlet containers will complain that you have violated the spec, and will refuse to handle it.

A more elegant solution is more work - modify the original servlet/JSP that processes the parameter, so that it expects a request attribute instead of a parameter. The filter examines the parameter, sanitizes it, and sets the attribute (using request.setAttribute) with the sanitized value. No subclassing, no spoofing, but does require you to modify other parts of your application.

Oracle: If Table Exists

The best and most efficient way is to catch the "table not found" exception: this avoids the overhead of checking if the table exists twice; and doesn't suffer from the problem that if the DROP fails for some other reason (that might be important) the exception is still raised to the caller:

BEGIN
   EXECUTE IMMEDIATE 'DROP TABLE ' || table_name;
EXCEPTION
   WHEN OTHERS THEN
      IF SQLCODE != -942 THEN
         RAISE;
      END IF;
END;

ADDENDUM For reference, here are the equivalent blocks for other object types:

Sequence

BEGIN
  EXECUTE IMMEDIATE 'DROP SEQUENCE ' || sequence_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2289 THEN
      RAISE;
    END IF;
END;

View

BEGIN
  EXECUTE IMMEDIATE 'DROP VIEW ' || view_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Trigger

BEGIN
  EXECUTE IMMEDIATE 'DROP TRIGGER ' || trigger_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4080 THEN
      RAISE;
    END IF;
END;

Index

BEGIN
  EXECUTE IMMEDIATE 'DROP INDEX ' || index_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1418 THEN
      RAISE;
    END IF;
END;

Column

BEGIN
  EXECUTE IMMEDIATE 'ALTER TABLE ' || table_name
                || ' DROP COLUMN ' || column_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -904 AND SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Database Link

BEGIN
  EXECUTE IMMEDIATE 'DROP DATABASE LINK ' || dblink_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2024 THEN
      RAISE;
    END IF;
END;

Materialized View

BEGIN
  EXECUTE IMMEDIATE 'DROP MATERIALIZED VIEW ' || mview_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -12003 THEN
      RAISE;
    END IF;
END;

Type

BEGIN
  EXECUTE IMMEDIATE 'DROP TYPE ' || type_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Constraint

BEGIN
  EXECUTE IMMEDIATE 'ALTER TABLE ' || table_name
            || ' DROP CONSTRAINT ' || constraint_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -2443 AND SQLCODE != -942 THEN
      RAISE;
    END IF;
END;

Scheduler Job

BEGIN
  DBMS_SCHEDULER.drop_job(job_name);
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -27475 THEN
      RAISE;
    END IF;
END;

User / Schema

BEGIN
  EXECUTE IMMEDIATE 'DROP USER ' || user_name;
  /* you may or may not want to add CASCADE */
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1918 THEN
      RAISE;
    END IF;
END;

Package

BEGIN
  EXECUTE IMMEDIATE 'DROP PACKAGE ' || package_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Procedure

BEGIN
  EXECUTE IMMEDIATE 'DROP PROCEDURE ' || procedure_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Function

BEGIN
  EXECUTE IMMEDIATE 'DROP FUNCTION ' || function_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -4043 THEN
      RAISE;
    END IF;
END;

Tablespace

BEGIN
  EXECUTE IMMEDIATE 'DROP TABLESPACE' || tablespace_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -959 THEN
      RAISE;
    END IF;
END;

Synonym

BEGIN
  EXECUTE IMMEDIATE 'DROP SYNONYM ' || synonym_name;
EXCEPTION
  WHEN OTHERS THEN
    IF SQLCODE != -1434 THEN
      RAISE;
    END IF;
END;

Cannot get a text value from a numeric cell “Poi”

As explained in the Apache POI Javadocs, you should not use cell.setCellType(Cell.CELL_TYPE_STRING) to get the string value of a numeric cell, as you'll loose all the formatting

Instead, as the javadocs explain, you should use DataFormatter

What DataFormatter does is take the floating point value representing the cell is stored in the file, along with the formatting rules applied to it, and returns you a string that look like it the cell does in Excel.

So, if you're after a String of the cell, looking much as you had it looking in Excel, just do:

 // Create a formatter, do this once
 DataFormatter formatter = new DataFormatter(Locale.US);

 .....

 for (int i=1; i <= sheet.getLastRowNum(); i++) {
        Row r = sheet.getRow(i);
        if (r == null) { 
           // empty row, skip
        } else {
           String j_username = formatter.formatCellValue(row.getCell(0));
           String j_password =  formatter.formatCellValue(row.getCell(1));

           // Use these
        }
 }

The formatter will return String cells as-is, and for Numeric cells will apply the formatting rules on the style to the number of the cell

Is it possible to use std::string in a constexpr?

C++20 will add constexpr strings and vectors

The following proposal has been accepted apparently: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0980r0.pdf and it adds constructors such as:

// 20.3.2.2, construct/copy/destroy
constexpr
basic_string() noexcept(noexcept(Allocator())) : basic_string(Allocator()) { }
constexpr
explicit basic_string(const Allocator& a) noexcept;
constexpr
basic_string(const basic_string& str);
constexpr
basic_string(basic_string&& str) noexcept;

in addition to constexpr versions of all / most methods.

There is no support as of GCC 9.1.0, the following fails to compile:

#include <string>

int main() {
    constexpr std::string s("abc");
}

with:

g++-9 -std=c++2a main.cpp

with error:

error: the type ‘const string’ {aka ‘const std::__cxx11::basic_string<char>’} of ‘constexpr’ variable ‘s’ is not literal

std::vector discussed at: Cannot create constexpr std::vector

Tested in Ubuntu 19.04.

How to check if a number is between two values?

Here is the shortest method possible:

if (Math.abs(v-550)<50) console.log('short')
if ((v-500)*(v-600)<0) console.log('short')

Parametrized:

if (Math.abs(v-max+v-min)<max+min) console.log('short')
if ((v-min)*(v-max)<0) console.log('short')

You can divide both sides by 2 if you don't understand how the first one works;)

Convert double to Int, rounded down

If the double is a Double with capital D (a boxed primitive value):

Double d = 4.97542;
int i = (int) d.doubleValue();

// or directly:
int i2 = d.intValue();

If the double is already a primitive double, then you simply cast it:

double d = 4.97542;
int i = (int) d;

git: updates were rejected because the remote contains work that you do not have locally

The error possibly comes because of the different structure of the code that you are committing and that present on GitHub. You may refer to: How to deal with "refusing to merge unrelated histories" error:

$ git pull --allow-unrelated-histories
$ git push -f origin master

Setting a spinner onClickListener() in Android

The following works how you want it, but it is not ideal.

public class Tester extends Activity {

    String[] vals = { "here", "are", "some", "values" };
    Spinner spinner;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner = (Spinner) findViewById(R.id.spin);
        ArrayAdapter<String> ad = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, vals);
        spinner.setAdapter(ad);
        Log.i("", "" + spinner.getChildCount());
        Timer t = new Timer();
        t.schedule(new TimerTask() {

            @Override
            public void run() {
                int a = spinner.getCount();
                int b = spinner.getChildCount();
                System.out.println("Count =" + a);
                System.out.println("ChildCount =" + b);
                for (int i = 0; i < b; i++) {
                    View v = spinner.getChildAt(i);
                    if (v == null) {
                        System.out.println("View not found");
                    } else {
                        v.setOnClickListener(new View.OnClickListener() {

                            @Override
                            public void onClick(View v) {
                                        Log.i("","click");
                                        }
                        });
                    }
                }
            }
        }, 500);
    }
}

Let me know exactly how you need the spinner to behave, and we can work out a better solution.

Simple regular expression for a decimal with a precision of 2

This worked with me:

(-?[0-9]+(\.[0-9]+)?)

Group 1 is the your float number and group 2 is the fraction only.

Get number days in a specified month using JavaScript?

Another possible option would be to use Datejs

Then you can do

Date.getDaysInMonth(2009, 9)     

Although adding a library just for this function is overkill, it's always nice to know all the options you have available to you :)

Visual studio equivalent of java System.out

In System.Diagnostics,

Debug.Write()
Debug.WriteLine()

etc. will print to the Output window in VS.

How to preview a part of a large pandas DataFrame, in iPython notebook?

I write a method to show the four corners of the data and monkey-patch to dataframe to do so:

def _sw(df, up_rows=10, down_rows=5, left_cols=4, right_cols=3, return_df=False):
    ''' display df data at four corners
        A,B (up_pt)
        C,D (down_pt)
        parameters : up_rows=10, down_rows=5, left_cols=4, right_cols=3
        usage:
            df = pd.DataFrame(np.random.randn(20,10), columns=list('ABCDEFGHIJKLMN')[0:10])
            df.sw(5,2,3,2)
            df1 = df.set_index(['A','B'], drop=True, inplace=False)
            df1.sw(5,2,3,2)
    '''
    #pd.set_printoptions(max_columns = 80, max_rows = 40)
    ncol, nrow = len(df.columns), len(df)

    # handle columns
    if ncol <= (left_cols + right_cols) :
        up_pt = df.ix[0:up_rows, :]         # screen width can contain all columns
        down_pt = df.ix[-down_rows:, :]
    else:                                   # screen width can not contain all columns
        pt_a = df.ix[0:up_rows,  0:left_cols]
        pt_b = df.ix[0:up_rows,  -right_cols:]
        pt_c = df[-down_rows:].ix[:,0:left_cols]
        pt_d = df[-down_rows:].ix[:,-right_cols:]

        up_pt   = pt_a.join(pt_b, how='inner')
        down_pt = pt_c.join(pt_d, how='inner')
        up_pt.insert(left_cols, '..', '..')
        down_pt.insert(left_cols, '..', '..')

    overlap_qty = len(up_pt) + len(down_pt) - len(df)
    down_pt = down_pt.drop(down_pt.index[range(overlap_qty)]) # remove overlap rows

    dt_str_list = down_pt.to_string().split('\n') # transfer down_pt to string list

    # Display up part data
    print up_pt

    start_row = (1 if df.index.names[0] is None else 2) # start from 1 if without index

    # Display omit line if screen height is not enought to display all rows
    if overlap_qty < 0:
        print "." * len(dt_str_list[start_row])

    # Display down part data row by row
    for line in dt_str_list[start_row:]:
        print line

    # Display foot note
    print "\n"
    print "Index :",df.index.names
    print "Column:",",".join(list(df.columns.values))
    print "row: %d    col: %d"%(len(df), len(df.columns))
    print "\n"

    return (df if return_df else None)
DataFrame.sw = _sw  #add a method to DataFrame class

Here is the sample:

>>> df = pd.DataFrame(np.random.randn(20,10), columns=list('ABCDEFGHIJKLMN')[0:10])

>>> df.sw()
         A       B       C       D  ..       H       I       J
0  -0.8166  0.0102  0.0215 -0.0307  .. -0.0820  1.2727  0.6395
1   1.0659 -1.0102 -1.3960  0.4700  ..  1.0999  1.1222 -1.2476
2   0.4347  1.5423  0.5710 -0.5439  ..  0.2491 -0.0725  2.0645
3  -1.5952 -1.4959  2.2697 -1.1004  .. -1.9614  0.6488 -0.6190
4  -1.4426 -0.8622  0.0942 -0.1977  .. -0.7802 -1.1774  1.9682
5   1.2526 -0.2694  0.4841 -0.7568  ..  0.2481  0.3608 -0.7342
6   0.2108  2.5181  1.3631  0.4375  .. -0.1266  1.0572  0.3654
7  -1.0617 -0.4743 -1.7399 -1.4123  .. -1.0398 -1.4703 -0.9466
8  -0.5682 -1.3323 -0.6992  1.7737  ..  0.6152  0.9269  2.1854
9   0.2361  0.4873 -1.1278 -0.2251  ..  1.4232  2.1212  2.9180
10  2.0034  0.5454 -2.6337  0.1556  ..  0.0016 -1.6128 -0.8093
..............................................................
15  1.4091  0.3540 -1.3498 -1.0490  ..  0.9328  0.3668  1.3948
16  0.4528 -0.3183  0.4308 -0.1818  ..  0.1295  1.2268  0.1365
17 -0.7093  1.3991  0.9501  2.1227  .. -1.5296  1.1908  0.0318
18  1.7101  0.5962  0.8948  1.5606  .. -0.6862  0.9558 -0.5514
19  1.0329 -1.2308 -0.6896 -0.5112  ..  0.2719  1.1478 -0.1459


Index : [None]
Column: A,B,C,D,E,F,G,H,I,J
row: 20    col: 10


>>> df.sw(4,2,3,4)
        A       B       C  ..       G       H       I       J
0 -0.8166  0.0102  0.0215  ..  0.3671 -0.0820  1.2727  0.6395
1  1.0659 -1.0102 -1.3960  ..  1.0984  1.0999  1.1222 -1.2476
2  0.4347  1.5423  0.5710  ..  1.6675  0.2491 -0.0725  2.0645
3 -1.5952 -1.4959  2.2697  ..  0.4856 -1.9614  0.6488 -0.6190
4 -1.4426 -0.8622  0.0942  .. -0.0947 -0.7802 -1.1774  1.9682
..............................................................
18  1.7101  0.5962  0.8948  .. -0.8592 -0.6862  0.9558 -0.5514
19  1.0329 -1.2308 -0.6896  .. -0.3954  0.2719  1.1478 -0.1459


Index : [None]
Column: A,B,C,D,E,F,G,H,I,J
row: 20    col: 10

How does BitLocker affect performance?

My current work machine came with bitlocker, and being an upgrade from the prior model. It only seemed faster to me. What I have found, however, is that bitlocker is more bullet proof than truecrypt, when it comes to accurately laying down the data. I do a lot of work in SAS which constantly writes backup copies to disk as it moves along and shoots a variety of output types to disk at the end. SAS works fine writing output from multithreaded processes back to bitlocker and doesn't seem to know it's there. This has not been the case for me with truecrypt. I'm not sure what happens or how, but I found that processes got out of synch when working with source/output data in a truecrypt container, which is what I installed on my second work computer since it had no bitlocker. The constant backups were shooting to an SSD while the truecrypt results were on a regular HD. Maybe that speed difference helped trip it up. Whatever the cause, I had to quit using truecrypt on that second computer because it made my SAS results out of synch with respect to processing order and it screwed up some of my processes and data. Scary stuff in my world.

I work with people who have successfully used Truecrypt on the exact same computer, but they weren't using a disk intensive app. like SAS.

Bitlocker to Go, the encryption which bitlocker applies to thumb-drives, does slow things down quite a bit when it comes to read/write times. It's not too hard to use as long as you remember your password on the thumbdrive, and are willing to wait for it to format/initialize the drive, but in my experience it made access to the flash drive about 4 times as slow. Don't know why it would slow down a thumb drive and not a disk but that's how it was for me and my coworker.

Based on my success with bitlocker at work, I bought Windows Pro for my home computer to get bitlocker and plan to encrypt some directories with it for things like financials.

How to calculate growth with a positive and negative number?

Short one:

=IF(D2>C2, ABS((D2-C2)/C2), -1*ABS((D2-C2)/C2)) 

or confusing one (my first attempt):

=IF(D2>C2, IF(C2>0, (D2-C2)/C2, (D2-C2)/ABS(C2)), IF(OR(D2>0,C2>0), (D2-C2)/C2, IF(AND(D2<0, C2<0), (D2-C2)/ABS(C2), 0)))

D2 is this year, C2 is last year.

What is an AssertionError? In which case should I throw it from my own code?

An assertion Error is thrown when say "You have written a code that should not execute at all costs because according to you logic it should not happen. BUT if it happens then throw AssertionError. And you don't catch it." In such a case you throw an Assertion error.

new IllegalStateException("Must not instantiate an element of this class")' // Is an Exception not error.

Note: Assertion Error comes under java.lang.Error And Errors not meant to be caught.

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

Different connections pools have different configs.

For example Tomcat (default) expects:

spring.datasource.ourdb.url=...

and HikariCP will be happy with:

spring.datasource.ourdb.jdbc-url=...

We can satisfy both without boilerplate configuration:

spring.datasource.ourdb.jdbc-url=${spring.datasource.ourdb.url}

There is no property to define connection pool provider.

Take a look at source DataSourceBuilder.java

If Tomcat, HikariCP or Commons DBCP are on the classpath one of them will be selected (in that order with Tomcat first).

... so, we can easily replace connection pool provider using this maven configuration (pom.xml):

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.apache.tomcat</groupId>
                <artifactId>tomcat-jdbc</artifactId>
            </exclusion>
        </exclusions>
    </dependency>       

    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
    </dependency>

How can I view an old version of a file with Git?

To quickly see the differences with older revisions of a file:

git show -1 filename.txt > to compare against the last revision of file

git show -2 filename.txt > to compare against the 2nd last revision

git show -3 fielname.txt > to compare against the last 3rd last revision

Getting the size of an array in an object

Arrays have a property .length that returns the number of elements.

var st =
    {
        "itema":{},
        "itemb":
        [
            {"id":"s01","cd":"c01","dd":"d01"},
            {"id":"s02","cd":"c02","dd":"d02"}
        ]
    };

st.itemb.length // 2

Failed to start mongod.service: Unit mongod.service not found

You are missing a 'b' I think?

sudo service mongod start

should be

sudo service mongodb start

I think this is the case?

Database Structure for Tree Data Structure

If you have to use Relational DataBase to organize tree data structure then Postgresql has cool ltree module that provides data type for representing labels of data stored in a hierarchical tree-like structure. You can get the idea from there.(For more information see: http://www.postgresql.org/docs/9.0/static/ltree.html)

In common LDAP is used to organize records in hierarchical structure.

How to make audio autoplay on chrome

You could use <iframe src="link/to/file.mp3" allow="autoplay">, if the origin has an autoplay permission. More info here.

google map API zoom range

Available Zoom Levels

Zoom level 0 is the most zoomed out zoom level available and each integer step in zoom level halves the X and Y extents of the view and doubles the linear resolution.

Google Maps was built on a 256x256 pixel tile system where zoom level 0 was a 256x256 pixel image of the whole earth. A 256x256 tile for zoom level 1 enlarges a 128x128 pixel region from zoom level 0.

As correctly stated by bkaid, the available zoom range depends on where you are looking and the kind of map you are using:

  • Road maps - seem to go up to zoom level 22 everywhere
  • Hybrid and satellite maps - the max available zoom levels depend on location. Here are some examples:
  • Remote regions of Antarctica: 13
  • Gobi Desert: 17
  • Much of the U.S. and Europe: 21
  • "Deep zoom" locations: 22-23 (see bkaid's link)

Note that these values are for the Google Static Maps API which seems to give one more zoom level than the Javascript API. It appears that the extra zoom level available for Static Maps is just an upsampled version of the max-resolution image from the Javascript API.

Map Scale at Various Zoom Levels

Google Maps uses a Mercator projection so the scale varies substantially with latitude. A formula for calculating the correct scale based on latitude is:

meters_per_pixel = 156543.03392 * Math.cos(latLng.lat() * Math.PI / 180) / Math.pow(2, zoom)

Formula is from Chris Broadfoot's comment.


Google Maps basics

Zoom Level - zoom

0 - 19

0 lowest zoom (whole world)

19 highest zoom (individual buildings, if available) Retrieve current zoom level using mapObject.getZoom()


What you're looking for are the scales for each zoom level. Use these:

20 : 1128.497220
19 : 2256.994440
18 : 4513.988880
17 : 9027.977761
16 : 18055.955520
15 : 36111.911040
14 : 72223.822090
13 : 144447.644200
12 : 288895.288400
11 : 577790.576700
10 : 1155581.153000
9  : 2311162.307000
8  : 4622324.614000
7  : 9244649.227000
6  : 18489298.450000
5  : 36978596.910000
4  : 73957193.820000
3  : 147914387.600000
2  : 295828775.300000
1  : 591657550.500000

How to transform array to comma separated words string?

Directly from the docs:

$comma_separated = implode(",", $array);

What is the difference between null and undefined in JavaScript?

Both Null and undefined in JavaScript indicate absence of value.

var a = null; //variable assigned null value
var b;  // undefined

Despite the fact both exist for absence of value but: Undefined actually means the variable is not initialized. Functions that return nothing and function parameters for which no value is supplied, undefined value is returned. Use strict equality operator === to distinguish between null and undefined.

Reference: http://www.thesstech.com/javascript/null-and-undefined

html5 input for money/currency

Try using step="0.01", then it will step by a penny each time.

eg:

_x000D_
_x000D_
<input type="number" min="0.00" max="10000.00" step="0.01" />
_x000D_
_x000D_
_x000D_

Conditional Formatting (IF not empty)

This method works for Excel 2016, and calculates on cell value, so can be used on formula arrays (i.e. it will ignore blank cells that contain a formula).

  • Highlight the range.
  • Home > Conditional Formatting > New Rule > Use a Formula.
  • Enter "=LEN(#)>0" (where '#' is the upper-left-most cell in your range).
  • Alter the formatting to suit your preference.

Note: Len(#)>0 be altered to only select cell values above a certain length.

Note 2: '#' must not be an absolute reference (i.e. shouldn't contain '$').

Android Webview gives net::ERR_CACHE_MISS message

Answers assembled! I wanted to just combine all the answers into one comprehensive one.

1. Check if <uses-permission android:name="android.permission.INTERNET" /> is present in manifest.xml. Make sure that it is nested under <manifest> and not <application>. Thanks to sajid45 and Liyanis Velazquez

2. Ensure that you are using <uses-permission android:name="android.permission.INTERNET"/> instead of the deprecated <uses-permission android:name="android.permission.internet"/>. Much thanks to alan_shi and creos.

3. If minimum version is below KK, check that you have

if (18 < Build.VERSION.SDK_INT ){
    //18 = JellyBean MR2, KITKAT=19
    mWeb.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
}

or

if (Build.VERSION.SDK_INT >= 19) {
        mWebView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
}

because proper webview is only added in KK (SDK 19). Thanks to Devavrata, Mike ChanSeong Kim and Liyanis Velazquez

4. Ensure that you don't have webView.getSettings().setBlockNetworkLoads (false);. Thanks to TechNikh for pointing this out.

5. If all else fails, make sure that your Android Studio, Android SDK and the emulator image (if you are using one) is updated. And if you are still meeting the problem, just open a new question and make a comment below to your URL.

Moment.js get day name from date

With moment you can parse the date string you have:

var dt = moment(myDate.date, "YYYY-MM-DD HH:mm:ss")

That's for UTC, you'll have to convert the time zone from that point if you so desire.

Then you can get the day of the week:

dt.format('dddd');

Get epoch for a specific date using Javascript

Some answers does not explain the side effects of variations in the timezone for JavaScript Date object. So you should consider this answer if this is a concern for you.

Method 1: Machine's timezone dependent

By default, JavaScript returns a Date considering the machine's timezone, so getTime() result varies from computer to computer. You can check this behavior running:

new Date(1970, 0, 1, 0, 0, 0, 0).getTime()
    // Since 1970-01-01 is Epoch, you may expect ZERO
    // but in fact the result varies based on computer's timezone

This is not a problem if you really want the time since Epoch considering your timezone. So if you want to get time since Epoch for the current Date or even a specified Date based on the computer's timezone, you're free to continue using this method.

// Seconds since Epoch (Unix timestamp format)

new Date().getTime() / 1000             // local Date/Time since Epoch in seconds
new Date(2020, 11, 1).getTime() / 1000  // time since Epoch to 2020-12-01 00:00 (local timezone) in seconds

// Milliseconds since Epoch (used by some systems, eg. JavaScript itself)

new Date().getTime()                    // local Date/Time since Epoch in milliseconds
new Date(2020,  0, 2).getTime()         // time since Epoch to 2020-01-02 00:00 (local timezone) in milliseconds

// **Warning**: notice that MONTHS in JavaScript Dates starts in zero (0 = January, 11 = December)

Method 2: Machine's timezone independent

However, if you want to get ride of variations in timezone and get time since Epoch for a specified Date in UTC (that is, timezone independent), you need to use Date.UTC method or shift the date from your timezone to UTC:

Date.UTC(1970,  0, 1)
    // should be ZERO in any computer, since it is ZERO the difference from Epoch

    // Alternatively (if, for some reason, you do not want Date.UTC)
    const timezone_diff = new Date(1970, 0, 1).getTime()  // difference in milliseconds between your timezone and UTC
    (new Date(1970,  0, 1).getTime() - timezone_diff)
    // should be ZERO in any computer, since it is ZERO the difference from Epoch

So, using this method (or, alternatively, subtracting the difference), the result should be:

// Seconds since Epoch (Unix timestamp format)

Date.UTC(2020,  0, 1) / 1000  // time since Epoch to 2020-01-01 00:00 UTC in seconds

    // Alternatively (if, for some reason, you do not want Date.UTC)
    const timezone_diff = new Date(1970, 0, 1).getTime()
    (new Date(2020,  0, 1).getTime() - timezone_diff) / 1000  // time since Epoch to 2020-01-01 00:00 UTC in seconds
    (new Date(2020, 11, 1).getTime() - timezone_diff) / 1000  // time since Epoch to 2020-12-01 00:00 UTC in seconds

// Milliseconds since Epoch (used by some systems, eg. JavaScript itself)

Date.UTC(2020,  0, 2)   // time since Epoch to 2020-01-02 00:00 UTC in milliseconds

    // Alternatively (if, for some reason, you do not want Date.UTC)
    const timezone_diff = new Date(1970, 0, 1).getTime()
    (new Date(2020,  0, 2).getTime() - timezone_diff)         // time since Epoch to 2020-01-02 00:00 UTC in milliseconds

// **Warning**: notice that MONTHS in JavaScript Dates starts in zero (0 = January, 11 = December)

IMO, unless you know what you're doing (see note above), you should prefer Method 2, since it is machine independent.


End note

Although the recomendations in this answer, and since Date.UTC does not work without a specified date/time, you may be inclined in using the alternative approach and doing something like this:

const timezone_diff = new Date(1970, 0, 1).getTime()
(new Date().getTime() - timezone_diff)  // <-- !!! new Date() without arguments
    // means "local Date/Time subtracted by timezone since Epoch" (?)

This does not make any sense and it is probably WRONG (you are modifying the date). Be aware of not doing this. If you want to get time since Epoch from the current date AND TIME, you are most probably OK using Method 1.

jQuery SVG, why can't I addClass?

There is element.classList in the DOM API that works for both HTML and SVG elements. No need for jQuery SVG plugin or even jQuery.

$(".jimmy").click(function() {
    this.classList.add("clicked");
});

Design Documents (High Level and Low Level Design Documents)

High-Level Design (HLD) involves decomposing a system into modules, and representing the interfaces & invocation relationships among modules. An HLD is referred to as software architecture.

LLD, also known as a detailed design, is used to design internals of the individual modules identified during HLD i.e. data structures and algorithms of the modules are designed and documented.

Now, HLD and LLD are actually used in traditional Approach (Function-Oriented Software Design) whereas, in OOAD, the system is seen as a set of objects interacting with each other.

As per the above definitions, a high-level design document will usually include a high-level architecture diagram depicting the components, interfaces, and networks that need to be further specified or developed. The document may also depict or otherwise refer to work flows and/or data flows between component systems.

Class diagrams with all the methods and relations between classes come under LLD. Program specs are covered under LLD. LLD describes each and every module in an elaborate manner so that the programmer can directly code the program based on it. There will be at least 1 document for each module. The LLD will contain - a detailed functional logic of the module in pseudo code - database tables with all elements including their type and size - all interface details with complete API references(both requests and responses) - all dependency issues - error message listings - complete inputs and outputs for a module.

PHP combine two associative arrays into one array

array_merge() is more efficient but there are a couple of options:

$array1 = array("id1" => "value1");

$array2 = array("id2" => "value2", "id3" => "value3", "id4" => "value4");

$array3 = array_merge($array1, $array2/*, $arrayN, $arrayN*/);
$array4 = $array1 + $array2;

echo '<pre>';
var_dump($array3);
var_dump($array4);
echo '</pre>';


// Results:
    array(4) {
      ["id1"]=>
      string(6) "value1"
      ["id2"]=>
      string(6) "value2"
      ["id3"]=>
      string(6) "value3"
      ["id4"]=>
      string(6) "value4"
    }
    array(4) {
      ["id1"]=>
      string(6) "value1"
      ["id2"]=>
      string(6) "value2"
      ["id3"]=>
      string(6) "value3"
      ["id4"]=>
      string(6) "value4"
    }

Get Row Index on Asp.net Rowcommand event

If you have a built-in command of GridView like insert, update or delete, on row command you can use the following code to get the index:

int index = Convert.ToInt32(e.CommandArgument);

In a custom command, you can set the command argument to yourRow.RowIndex.ToString() and then get it back in the RowCommand event handler. Unless, of course, you need the command argument for another purpose.

How to host material icons offline?

I solved it using this package (@mdi/font) and importing it on main.js:

import '@mdi/font/css/materialdesignicons.css'

Visual Studio Code PHP Intelephense Keep Showing Not Necessary Error

This solution may help you if you know your problem is limited to Facades and you are running Laravel 5.5 or above.

Install laravel-ide-helper

composer require --dev barryvdh/laravel-ide-helper

Add this conditional statement in your AppServiceProvider to register the helper class.

public function register()
{
    if ($this->app->environment() !== 'production') {
        $this->app->register(\Barryvdh\LaravelIdeHelper\IdeHelperServiceProvider::class);
    }
    // ...
}

Then run php artisan ide-helper:generate to generate a file to help the IDE understand Facades. You will need to restart Visual Studio Code.

References

https://laracasts.com/series/how-to-be-awesome-in-phpstorm/episodes/16

https://github.com/barryvdh/laravel-ide-helper

How to get an Instagram Access Token

The easy way that works in 2019

Disable implicit oauth under the security auth and THEN load this:

https://api.instagram.com/oauth/authorize/?client_id=CLIENT-ID&redirect_uri=REDIRECT-URI&response_type=token

Specify REDIRECT-URI in your account and type it exactly as specified.

Round up value to nearest whole number in SQL UPDATE

If you want to round off then use the round function. Use ceiling function when you want to get the smallest integer just greater than your argument.

For ex: select round(843.4923423423,0) from dual gives you 843 and

select round(843.6923423423,0) from dual gives you 844

How do you redirect HTTPS to HTTP?

If none of the above solutions work for you (they did not for me) here is what worked on my server:

RewriteCond %{HTTPS} =on
RewriteRule ^(.*)$ http://%{HTTP_HOST}/$1 [L,R=301]

Automatically create an Enum based on values in a database lookup table?

One way to keep the Enums and to create a Dynamic list of values at the same time is to use the Enums that you currently have with a Dynamically created Dictionary.

Since most Enums are used in the context that they are defined to be used, and the "dynamic enums" will be supported by dynamic processes, you can distinguish the 2.

The first step is to create a table/collection that houses the IDs and References for the Dynamic Entries. In the table you will autoincrement much larger than your largest Enum value.

Now comes the part for your dynamic Enums, I am assuming that you will be using the Enums to create a set of conditions that apply a set of rules, some are dynamically generated.

Get integer from database
If Integer is in Enum -> create Enum -> then run Enum parts
If Integer is not a Enum -> create Dictionary from Table -> then run Dictionary parts.

setting content between div tags using javascript

If the number of your messages is limited then the following may help. I used jQuery for the following example, but it works with plain js too.

The innerHtml property did not work for me. So I experimented with ...

    <div id=successAndErrorMessages-1>100% OK</div>
    <div id=successAndErrorMessages-2>This is an error mssg!</div>

and toggled one of the two on/off ...

 $("#successAndErrorMessages-1").css('display', 'none')
 $("#successAndErrorMessages-2").css('display', '')

For some reason I had to fiddle around with the ordering before it worked in all types of browsers.

How can I submit form on button click when using preventDefault()?

Ok, first e.preventDefault(); it's not a Jquery element, it's a method of javascript, now what it's true it's if you add this method you avoid the submit the event, now what you could do it's send the form by ajax something like this

$('#subscription_order_form').submit(function(e){
    $.ajax({
     url: $(this).attr('action'),
     data : $(this).serialize(),
     success : function (data){

      }
   });
    e.preventDefault();
});

Tensorflow image reading & display

(Can't comment, not enough reputation, but here is a modified version that worked for me)

To @HamedMP error about the No default session is registered you can use InteractiveSession to get rid of this error: https://www.tensorflow.org/versions/r0.8/api_docs/python/client.html#InteractiveSession

And to @NumesSanguis issue with Image.show, you can use the regular PIL .show() method because fromarray returns an image object.

I do both below (note I'm using JPEG instead of PNG):

import tensorflow as tf
import numpy as np
from PIL import Image

filename_queue = tf.train.string_input_producer(['my_img.jpg']) #  list of files to read

reader = tf.WholeFileReader()
key, value = reader.read(filename_queue)

my_img = tf.image.decode_jpeg(value) # use png or jpg decoder based on your files.

init_op = tf.initialize_all_variables()
sess = tf.InteractiveSession()
with sess.as_default():
    sess.run(init_op)

# Start populating the filename queue.

coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(coord=coord)

for i in range(1): #length of your filename list
  image = my_img.eval() #here is your image Tensor :) 

Image.fromarray(np.asarray(image)).show()

coord.request_stop()
coord.join(threads)

Getting a 'source: not found' error when using source in a bash script

In the POSIX standard, which /bin/sh is supposed to respect, the command is . (a single dot), not source. The source command is a csh-ism that has been pulled into bash.

Try

. $env_name/bin/activate

Or if you must have non-POSIX bash-isms in your code, use #!/bin/bash.

Eclipse: The declared package does not match the expected package

Happens for me after failed builds run outside of the IDE. If cleaning your workspace doesn't work, try: 1) Delete all projects 2) Close and restart STS/eclipse, 3) Re-import the projects

How do I install an R package from source?

From cran, you can install directly from a github repository address. So if you want the package at https://github.com/twitter/AnomalyDetection:

library(devtools)
install_github("twitter/AnomalyDetection")

does the trick.

How to format number of decimal places in wpf using style/template?

The accepted answer does not show 0 in integer place on giving input like 0.299. It shows .3 in WPF UI. So my suggestion to use following string format

<TextBox Text="{Binding Value,  StringFormat={}{0:#,0.0}}" 

Is it a good practice to place C++ definitions in header files?

IMHO, He has merit ONLY if he's doing templates and/or metaprogramming. There's plenty of reasons already mentioned that you limit header files to just declarations. They're just that... headers. If you want to include code, you compile it as a library and link it up.

Spring Data JPA findOne() change to Optional how to use this?

Indeed, in the latest version of Spring Data, findOne returns an optional. If you want to retrieve the object from the Optional, you can simply use get() on the Optional. First of all though, a repository should return the optional to a service, which then handles the case in which the optional is empty. afterwards, the service should return the object to the controller.

Call removeView() on the child's parent first

Solution:

((ViewGroup)scrollChildLayout.getParent()).removeView(scrollChildLayout);
//scrollView.removeView(scrollChildLayout);

Use the child element to get a reference to the parent. Cast the parent to a ViewGroup so that you get access to the removeView method and use that.

Thanks to @Dongshengcn for the solution

Running Groovy script from the command line

#!/bin/sh
sed '1,2d' "$0"|$(which groovy) /dev/stdin; exit;

println("hello");

How do you add an in-app purchase to an iOS application?

RMStore is a lightweight iOS library for In-App Purchases. It wraps StoreKit API and provides you with handy blocks for asynchronous requests. Purchasing a product is as easy as calling a single method.

For the advanced users, this library also provides receipt verification, content downloads and transaction persistence.

Convert String to Uri

I am just using the java.net package. Here you can do the following:

...
import java.net.URI;
...

String myUrl = "http://stackoverflow.com";
URI myURI = new URI(myUrl);

Determine what user created objects in SQL Server

If you need a small and specific mechanism, you can search for DLL Triggers info.

Foreach Control in form, how can I do something to all the TextBoxes in my Form?

Even better, you can encapsule this to clear any type of controls you want in one method, like this:

public static void EstadoControles<T>(object control, bool estado, bool limpiar = false) where T : Control
        {
            foreach (var textEdits in ((T)control).Controls.OfType<TextEdit>()) textEdits.Enabled = estado;
            foreach (var textLookUpEdits in ((T)control).Controls.OfType<LookUpEdit>()) textLookUpEdits.Enabled = estado;

            if (!limpiar) return;
            {
                foreach (var textEdits in ((T)control).Controls.OfType<TextEdit>()) textEdits.Text = string.Empty;
                foreach (var textLookUpEdits in ((T)control).Controls.OfType<LookUpEdit>()) textLookUpEdits.EditValue = @"-1";
            }
        }

In Powershell what is the idiomatic way of converting a string to an int?

$source = "number35"

$number=$null

$result = foreach ($_ in $source.ToCharArray()){$digit="0123456789".IndexOf($\_,0);if($digit -ne -1){$number +=$\_}}[int32]$number

Just feed it digits and it wil convert to an Int32

Get button click inside UITableViewCell

1) In your cellForRowAtIndexPath: method, assign button tag as index:

cell.yourbutton.tag = indexPath.row;

2) Add target and action for your button as below:

[cell.yourbutton addTarget:self action:@selector(yourButtonClicked:) forControlEvents:UIControlEventTouchUpInside];

3) Code actions based on index as below in ViewControler:

-(void)yourButtonClicked:(UIButton*)sender
{
     if (sender.tag == 0) 
     {
         // Your code here
     }
}

Updates for multiple Section:

You can check this link to detect button click in table view for multiple row and section.

Boolean Field in Oracle

The best option is 0 and 1 (as numbers - another answer suggests 0 and 1 as CHAR for space-efficiency but that's a bit too twisted for me), using NOT NULL and a check constraint to limit contents to those values. (If you need the column to be nullable, then it's not a boolean you're dealing with but an enumeration with three values...)

Advantages of 0/1:

  • Language independent. 'Y' and 'N' would be fine if everyone used it. But they don't. In France they use 'O' and 'N' (I have seen this with my own eyes). I haven't programmed in Finland to see whether they use 'E' and 'K' there - no doubt they're smarter than that, but you can't be sure.
  • Congruent with practice in widely-used programming languages (C, C++, Perl, Javascript)
  • Plays better with the application layer e.g. Hibernate
  • Leads to more succinct SQL, for example, to find out how many bananas are ready to eat select sum(is_ripe) from bananas instead of select count(*) from bananas where is_ripe = 'Y' or even (yuk) select sum(case is_ripe when 'Y' then 1 else 0) from bananas

Advantages of 'Y'/'N':

  • Takes up less space than 0/1
  • It's what Oracle suggests, so might be what some people are more used to

Another poster suggested 'Y'/null for performance gains. If you've proven that you need the performance, then fair enough, but otherwise avoid since it makes querying less natural (some_column is null instead of some_column = 0) and in a left join you'll conflate falseness with nonexistent records.

What is the difference between primary, unique and foreign key constraints, and indexes?

Primary key mainly prevent duplication and shows the uniqueness of columns Foreign key mainly shows relationship on two tables

How do I make a composite key with SQL Server Management Studio?

Highlight both rows in the table design view and click on the key icon, they will now be a composite primary key.

I'm not sure of your question, but only one column per table may be an IDENTITY column, not both.

Java out.println() how is this possible?

out is a PrintStream type of static variable(object) of System class and println() is function of the PrintStream class.

class PrintStream
{
    public void println(){}    //member function
    ...
}

class System
{
    public static final PrintStream out;   //data member
    ...
}

That is why the static variable(object) out is accessed with the class name System which further invokes the method println() of it's type PrintStream (which is a class).

how to get date of yesterday using php?

you can do this by

date("F j, Y", time() - 60 * 60 * 24);

or by

date("F j, Y", strtotime("yesterday"));