Tutorial by Examples: r

HTML comments (optionally preceded by whitespace) will cause code (on the same line) to be ignored by the browser also, though this is considered bad practice. One-line comments with the HTML comment opening sequence (<!--): Note: the JavaScript interpreter ignores the closing characters of H...

When developing several applications on one machine, it becomes useful to separate out dependencies into virtual environments. With the use of virtualenv, these environments are sourced into your shell so that when you run a command, it comes from that virtual environment. This is most commonly in...

To setup a new credential profile with the name myprofile: $ aws configure --profile myprofile AWS Access Key ID [None]: ACCESSKEY AWS Secret Access Key [None]: SECRETKEY Default region name [None]: REGIONNAME Default output format [None]: text | table | json For the AWS access key id and se...

Joining a subquery is often used when you want to get aggregate data from a child/details table and display that along with records from the parent/header table. For example, you might want to get a count of child records, an average of some numeric column in child records, or the top or bottom row ...

Activity is the root UserInterface in Android and have it's own life-cycle. MainActivity.java public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Toast.makeText(this, "Activ...

In ASP.NET Core there are several different ways we can localize/globalize our app. It's important to pick a way that suits your needs. In this example you'll see how we can make a multilingual ASP.NET Core app that reads language specific strings from .json files and store them in memory to provi...

brew install mpich

brew install open-mpi

There are two ways to define functions with multiple parameters in F#, Curried functions and Tupled functions. let curriedAdd x y = x + y // Signature: x:int -> y:int -> int let tupledAdd (x, y) = x + y // Signature: x:int * y:int -> int All functions defined from outside F# (such as ...

The term 'heap' is a general computing term meaning an area of memory from which portions can be allocated and deallocated independently of the memory provided by the stack. In C++ the Standard refers to this area as the Free Store which is considered a more accurate term. Areas of memory allocate...

A std::string containing a number can be converted into an integer type, or a floating point type, using conversion functions. Note that all of these functions stop parsing the input string as soon as they encounter a non-numeric character, so "123abc" will be converted into 123. The s...

Arithmetic operations are performed elementwise on Numpy arrays. For arrays of identical shape, this means that the operation is executed between elements at corresponding indices. # Create two arrays of the same size a = np.arange(6).reshape(2, 3) b = np.ones(6).reshape(2, 3) a # array([0, 1...

app/pipes.pipe.ts import { Pipe, PipeTransform } from '@angular/core'; @Pipe({name: 'truthy'}) export class Truthy implements PipeTransform { transform(value: any, truthy: string, falsey: string): any { if (typeof value === 'boolean'){return value ? truthy : falsey;} else return va...

Enumerable.Repeat generates a sequence of a repeated value. In this example it generates "Hello" 4 times. var repeats = Enumerable.Repeat("Hello", 4); foreach (var item in repeats) { Console.WriteLine(item); } /* output: Hello Hello Hello Hell...

import random probability = 0.3 if random.random() < probability: print("Decision with probability 0.3") else: print("Decision with probability 0.7")

The fundamental concept of the customizer is that admins can live preview changes to their site, and then permanently add them. The following can be copied and pasted into a theme's functions.php file to Add a customizer section called My First Section Add a customizer setting called Hello Worl...

MySQL3.19 Checks if a string matches a regular expression (defined by another string). SELECT 'bedded' REGEXP '[a-f]' -- returns True SELECT 'beam' REGEXP '[a-f]' -- returns False

The simplest way to run your job is to use mpiexec or mpirun (they are usually the same thing and aliases of each other). mpiexec -n 2 ./my_prog

Alternate return is a facility to control the flow of execution on return from a subroutine. It is often used as a form of error handling: real x call sub(x, 1, *100, *200) print*, "Success:", x stop 100 print*, "Negative input value" stop 200 print*, "Input va...

Installing aws cli in Ubuntu / Debian Instance sudo apt-get install -y python-dev python-pip sudo pip install awscli aws --version aws configure Installing aws cli using python Using pip you can install aws cli in windows, OS X and Linux sudo pip install awscli Configuring the AWS Comman...