Tutorial by Examples: d

Semi-transparent markers in line and scatter plots

Since Matlab R2014b it is easily possible to achieve semi-transparent markers for line and scatter plots using undocumented features introduced by Yair Altman. The basic idea is to get the hidden handle of the markers and apply a value < 1 for the last value in the EdgeColorData to achieve the d...

MATLAB Language • Undocumented Features

Do not catch everything!

While it's often tempting to catch every Exception: try: very_difficult_function() except Exception: # log / try to reconnect / exit gratiously finally: print "The END" # it runs no matter what execute. Or even everything (that includes BaseException and all its c...

Python Language • Exceptions

Using Single-case Discriminated Unions as Records

Sometimes it is useful to create union types with only one case to implement record-like types: type Point = Point of float * float let point1 = Point(0.0, 3.0) let point2 = Point(-2.5, -4.0) These become very useful because they can be decomposed via pattern matching in the same way as tu...

F# • Discriminated Unions

Inheritance - definition

Information Inheritance allows you to derive a new class from an existing class. You do this using the INHERITING FROM addition in the CLASS subclass DEFINITION INHERITING FROM superclass. statement. The new class subclass inherits all of the components of the existing class superclass. The n...

ABAP • ABAP Objects

Inheritance - Abstract and Final Methods and Classes

Information The ABSTRACT and FINAL additions to the METHODS and CLASS statements allow you to define abstract and final methods or classes. An abstract method is defined in an abstract class and cannot be implemented in that class. Instead, it is implemented in a subclass of the class. Abstra...

ABAP • ABAP Objects

Assertion of Unreachable Code

During development, when certain code paths must be prevented from the reach of control flow, you may use assert(0) to indicate that such a condition is erroneous: switch (color) { case COLOR_RED: case COLOR_GREEN: case COLOR_BLUE: break; default: assert(0); ...

C Language • Assertion

Escaping curly brackets inside a String.Format() expression

string outsidetext = "I am outside of bracket"; string.Format("{{I am in brackets!}} {0}", outsidetext); //Outputs "{I am in brackets!} I am outside of bracket"

C# Language • String.Format

Distance Filter using

Example : CLLocationManager *locationManager = [[CLLocationManager alloc] init]; locationManager.delegate = self; locationManager.desiredAccuracy = kCLLocationAccuracyBest; locationManager.distanceFilter = 5; E.g. In the above example code above, location changes of less than 5 m...

iOS • CLLocation

Using ngStorage to share data

Firstly, include the ngStorage source in your index.html. An example injecting ngStorage src would be: <head> <title>Angular JS ngStorage</title> <script src = "http://ajax.googleapis.com/ajax/libs/angularjs/1.3.14/angular.min.js"></script> &l...

AngularJS • Sharing Data

Friendship

The friend keyword is used to give other classes and functions access to private and protected members of the class, even through they are defined outside the class`s scope. class Animal{ private: double weight; double height; public: friend void printWeight(Animal animal); fr...

C++ • Classes/Structures

Declaring permissions in your manifest file

Any permission required by your application to access a protected part of the API or to interact with other applications must be declared in your AndroidManifest.xml file. This is done using the <uses-permission /> tag. Syntax <uses-permission android:name="string" android...

Android • The Manifest File

Create Single Gift Card

// Instantiate Gift Card Model $gift_card = Mage::getModel('enterprise_giftcardaccount/giftcardaccount'); // Populate Gift Card values $gift_card // Your redeemable code, doesn't have to be in this format. ->setCode('2i2j2j-24k1ii1-67774k-231l') // Also has STATUS_DISABLED ...

magento • Create Enterprise Gift Cards Programmatically

Mistakenly writing = instead of == when comparing

The = operator is used for assignment. The == operator is used for comparison. One should be careful not to mix the two. Sometimes one mistakenly writes /* assign y to x */ if (x = y) { /* logic */ } when what was really wanted is: /* compare if x is equal to y */ if (x == y) { ...

C Language • Common pitfalls

Getting a shell into a running (detached) container

Log into a running container A user can enter a running container in a new interactive bash shell with exec command. Say a container is called jovial_morse then you can get an interactive, pseudo-TTY bash shell by running: docker exec -it jovial_morse bash Log into a running container with a s...

Docker • Running containers

Instance methods

An instance method is a method that's available on a particular instance of a class, after the instance has been instantiated: MyClass *instance = [MyClass new]; [instance someInstanceMethod]; Here's how you define one: @interface MyClass : NSObject - (void)someInstanceMethod; // "-&qu...

Objective-C Language • Methods

Using an extension method for collection initialization

Collection initialization syntax can be used when instantiating any class which implements IEnumerable and has a method named Add which takes a single parameter. In previous versions, this Add method had to be an instance method on the class being initialized. In C#6, it can also be an extension me...

C# Language • C# 6.0 Features

Simple Actor DSL

To create simple actors without creating a new class, you can use: import akka.actor.ActorDSL._ import akka.actor.ActorSystem implicit val system = ActorSystem("demo") val a = actor(new Act { become { case "hello" ⇒ sender() ! "hi" } })

akka • Actor DSL

Nested Actors

It is also possible to create nested actors, i.e. grand-children, like this: // here we pass in the ActorRefFactory explicitly as an example val a = actor(system, "fred")(new Act { val b = actor("barney")(new Act { whenStarting { context.parent ! ("hello from &quot...

akka • Actor DSL

Get Apache Cordova Tools in Visual Studio

Open Control Panel -> Programs and Features, choose the Visual Studio 2015 item, and then choose the Change button. In the setup wizard for Visual Studio, choose the Modify button. In the list of optional features to install, select the HTML/JavaScript (Apache Cordova) checkbox, c...

Cordova • Visual Studio Tools for Apache Cordova

Update Apache Cordova Tools in Visual Studio

In Visual Studio, choose Tools->Extensions and Updates. In the Updates tab of the Extensions and Updates dialog box, choose Product Updates. If an update for Visual Studio Tools for Apache appears, select it, and then choose the Update button.

Cordova • Visual Studio Tools for Apache Cordova