Tutorial by Examples: ar

Warning: Elements in a ReadOnlyCollection are not inherently read-only

If the source collection is of a type that is not immutable, elements accessed through a ReadOnlyCollection can be modified. public class Item { public string Name { get; set; } public decimal Price { get; set; } } public static void FillOrder() { // An order is generated ...

.NET Framework • ReadOnlyCollections

Iterating over a range

You can easily do something to each element in a range. (1..5).each do |i| print i end # 12345

Ruby Language • Range

Getting Nearby Places from Current Location

Prerequisites Install pods in your project Install the GooglePlaces SDK Enable location services First we need to get the users location by getting their current longitude and latitude. Import GooglePlaces and GooglePlacePicker import GooglePlaces import GooglePlacePicker Add the...

iOS • iOS Google Places API

Order of function parameter execution

The order of execution of parameters is undefined in C programming. Here it may execute from left to right or from right to left. The order depends on the implementation. #include <stdio.h> void function(int a, int b) { printf("%d %d\n", a, b); } int main(void) { ...

C Language • Function Parameters

Alter default search_path of user

With the below commands, user's default search_path can be set. Check search path before set default schema. postgres=# \c postgres user1 You are now connected to database "postgres" as user "user1". postgres=> show search_path; search_path ---------------- &q...

postgresql • Role Management

Addition of two vectors using OpenMP parallel for construct

void parallelAddition (unsigned N, const double *A, const double *B, double *C) { unsigned i; #pragma omp parallel for shared (A,B,C,N) private(i) schedule(static) for (i = 0; i < N; ++i) { C[i] = A[i] + B[i]; } } This example adds two vector (A and B into...

openmp • Loop parallelism in OpenMP

Conditional clauses in OpenMP parallel regions

#include <omp.h> #include <stdio.h> int main (void) { int t = (0 == 0); // true value int f = (1 == 0); // false value #pragma omp parallel if (f) { printf ("FALSE: I am thread %d\n", omp_get_thread_num()); } #pragma omp parallel if (t) { printf (&quo...

openmp • Conditional parallel execution

Parallel processing of a c++ list container using OpenMP tasks

#include <omp.h> #include <unistd.h> #include <iostream> #include <list> static void processElement (unsigned n) { // Tell who am I. The #pragma omp critical ensures that // only one thread sends data to std::cout #pragma omp critical std::cout <...

openmp • Irregular OpenMP parallelism

Pivot and unpivot tabular data with data.table - I

Convert from wide form to long form Load data USArrests from datasets. data("USArrests") head(USArrests) Murder Assault UrbanPop Rape Alabama 13.2 236 58 21.2 Alaska 10.0 263 48 44.5 Arizona 8.1 294 80 31.0 Arkansas 8...

R Language • Pivot and unpivot with data.table

Pivot and unpivot tabular data with data.table - II

Convert from long form to wide form To recover data from the previous example, use dcast like so. DTc <- dcast(DTmu, State + UrbanPop ~ Crime) This gives the data in the original wide form. State UrbanPop Murder Assault Rape 1: Alabama 58 13.2 236 21.2 2:...

R Language • Pivot and unpivot with data.table

Localize Variables with @at-root directive

@at-root directive can be used to localize variables. $color: blue; @at-root { $color: red; .a { color: $color; } .b { color: $color; } } .c { color: $color; } is compiled to: .a { color: red; } .b { color: red; } .c { color: blue; }

sass • Variables

Get the value of a function of two or more arguments

In many application it is necessary to compute the function of two or more arguments. Traditionally, we use for-loops. For example, if we need to calculate the f = exp(-x^2-y^2) (do not use this if you need fast simulations): % code1 x = -1.2:0.2:1.4; y = -2:0.25:3; for nx=1:lenght(x) for n...

MATLAB Language • Vectorization

Downloading a file using the Dropbox Java library

This uses the Dropbox Java SDK to download a file from the Dropbox API at the remote path /Homework/math/Prime_Numbers.txt to the local file Prime_Numbers.txt: String localPath = "Prime_Numbers.txt"; OutputStream outputStream = new FileOutputStream(localPath); FileMetadata metadata = cl...

Dropbox API • Downloading a file

"Hello World" as a library

This example shows how to deploy the "Hello World" program as a library and how to link it with other targets. Say we have the same set of source/header files as in the http://www.riptutorial.com/cmake/example/22391/-hello-world--with-multiple-source-files example. Instead of building fro...

cmake • Getting started with cmake

When are bit-fields useful?

A bit-field is used to club together many variables into one object, similar to a structure. This allows for reduced memory usage and is especially useful in an embedded environment. e.g. consider the following variables having the ranges as given below. a --> range 0 - 3 b --> range 0 -...

C Language • Bit-fields

Angular 2 for-loop

For live plnkr click... <!doctype html> <html> <head> <title>ng for loop in angular 2 with ES5.</title> <script type="text/javascript" src="https://code.angularjs.org/2.0.0-alpha.28/angular2.sfx.dev.js"></script> <scr...

Angular 2 • Angular - ForLoop

Extract the text contents from a div with a particular id

Taggy-lens allows us to use lenses to parse and inspect HTML documents. #!/usr/bin/env stack -- stack --resolver lts-7.0 --install-ghc runghc --package text --package lens --package taggy-lens {-# LANGUAGE OverloadedStrings #-} import qualified Data.Text.Lazy as TL import qualified Data.Tex...

Haskell Language • Parsing HTML with taggy-lens and lens

Array in CFScript

<cfscript> oneDimensionArray = ArrayNew(1); oneDimensionArray[1] = 1; oneDimensionArray[2] = 'one'; oneDimensionArray[3] = '1'; </cfscript> <cfif IsDefined("oneDimensionArray")> <cfdump var="#oneDimensionArray#"> </cfif>...

coldfusion • ColdFusion Arrays

Increment-Decrement operators as arguments in Methods

Though Go supports ++ and -- operators and the behaviour is found to be almost similar to c/c++, variables with such operators cannot be passed as argument to function. package main import ( "fmt" ) func abcd(a int, b int) { fmt.Println(a," &...

Go • Methods

Complete and Partial Active Patterns

There are two types of Active Patterns that somewhat differ in usage - Complete and Partial. Complete Active Patterns can be used when you are able to enumerate all the outcomes, like "is a number odd or even?" let (|Odd|Even|) number = if number % 2 = 0 then Even else Odd N...

F# • Active Patterns