Tutorial by Examples: r

Vectors in R can have different types (e.g. integer, logical, character). The most general way of defining a vector is by using the function vector(). vector('integer',2) # creates a vector of integers of size 2. vector('character',2) # creates a vector of characters of size 2. vector('logical',2...

Detailed instructions on getting pymongo set up or installed. Installing with Pip To install pymongo for the first time: pip install pymongo Installing a specific version of pymongo: Where X.X.X is the version to be installed pip install pymongo==X.X.X Upgrading existing pymon...

Stanford CoreNLP is a popular Natural Language Processing toolkit supporting many core NLP tasks. To download and install the program, either download a release package and include the necessary *.jar files in your classpath, or add the dependency off of Maven central. See the download page for mor...

Adding a Conditional attribute from System.Diagnostics namespace to a method is a clean way to control which methods are called in your builds and which are not. #define EXAMPLE_A using System.Diagnostics; class Program { static void Main() { ExampleA(); // This method will ...

Whitespace is handled by the lexical analyzer before being parsed. The lexical analyzer uses a stack to store indentation levels. At the beginning, the stack contains just the value 0, which is the leftmost position. Whenever a nested block begins, the new indentation level is pushed on the stack, ...

-- Drop an index for column 'name' in table 'my_table' DROP INDEX idx_name ON my_table;

Creating a custom directive with isolated scope will separate the scope inside the directive from the outside scope, in order to prevent our directive from accidentally change the data in the parent scope and restricting it from reading private data from the parent scope. To create an isolated scop...

Racket functions can also have keyword arguments, which are specified with a keyword followed by the argument expression. A keyword begins with the characters #:, so a keyword argument looks like #:keyword arg-expr. Within a function call this looks like (function #:keyword arg-expr). > (define ...

Use Kernel.inspect to convert anything to string. iex> Kernel.inspect(1) "1" iex> Kernel.inspect(4.2) "4.2" iex> Kernel.inspect %{pi: 3.14, name: "Yos"} "%{pi: 3.14, name: \"Yos\"}"

iex> my_string = "Lorem ipsum dolor sit amet, consectetur adipiscing elit." iex> String.slice my_string, 6..10 "ipsum"

iex> String.split("Elixir, Antidote, Panacea", ",") ["Elixir", "Antidote", "Panacea"]

First, references will be added to the CLR assemblies that will be used. import clr clr.AddReference('System.Windows.Forms') Next the names we will use are imported. from System.Windows.Forms import Application, Form A class will be created for the Hello World form using Form as its subclas...

Threads are the low level parts of a computing system which command processing occurs. It is supported/provided by CPU/MCU hardware. There are also software methods. The purpose of multi-threading is doing calculations in parallel to each other if possible. Thus the desired result can be obtained in...

Components are simply instances that implement the Ashley component class. import com.badlogic.ashley.core.Component; import com.badlogic.ashley.core.ComponentMapper; public class Position implements Component { public static final ComponentMapper<Position> Map = ...

Entity systems are how you perform functional operations on sets of entities. Components should typically not have logic associated with them that involves awareness of data or state of other component instances, as that is the job of an entity system. An entity system can not be registered to mor...

Closures are inline anonymous methods that have the ability to use Parent method variables and other anonymous methods which are defined in the parent's scope. In essence, a closure is a block of code which can be executed at a later time, but which maintains the environment in which it was firs...

The IEnumerable<T> interface has a single method, GetEnumerator(), which returns an IEnumerator<T>. While the yield keyword can be used to directly create an IEnumerable<T>, it can also be used in exactly the same way to create an IEnumerator<T>. The only thing that changes ...

When an object implements the IDisposable interface, it can be created within the using syntax: using (var foo = new Foo()) { // do foo stuff } // when it reaches here foo.Dispose() will get called public class Foo : IDisposable { public void Dispose() { Console.WriteL...

Following is most basic expression tree that is created by lambda. Expression<Func<int, bool>> lambda = num => num == 42; To create expression trees 'by hand', one should use Expression class. Expression above would be equivalent to: ParameterExpression parameter = Expression.Pa...

This will create a timer to call the doSomething method on self in 5 seconds. Swift let timer = NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: Selector(doSomething()), userInfo: nil, ...