Tutorial by Examples: io

Table creation with Primary Key

CREATE TABLE Person ( PersonID INT UNSIGNED NOT NULL, LastName VARCHAR(66) NOT NULL, FirstName VARCHAR(66), Address VARCHAR(255), City VARCHAR(66), PRIMARY KEY (PersonID) ); A primary key is a NOT NULL single or a multi-column identifier whic...

MySQL • Table Creation

Table creation with Foreign Key

CREATE TABLE Account ( AccountID INT UNSIGNED NOT NULL, AccountNo INT UNSIGNED NOT NULL, PersonID INT UNSIGNED, PRIMARY KEY (AccountID), FOREIGN KEY (PersonID) REFERENCES Person (PersonID) ) ENGINE=InnoDB; Foreign key: A Foreign Key (FK) is either a single col...

MySQL • Table Creation

Installation or Setup

Detailed instructions on getting pandas set up or installed can be found here in the official documentation. Installing pandas with Anaconda Installing pandas and the rest of the NumPy and SciPy stack can be a little difficult for inexperienced users. The simplest way to install not only pandas, ...

pandas • Getting started with pandas

Installation or Setup

ReactJS is a JavaScript library contained in a single file react-<version>.js that can be included in any HTML page. People also commonly install the React DOM library react-dom-<version>.js along with the main React file: Basic Inclusion <!DOCTYPE html> <html> <...

React • Getting started with React

Installation or Setup

Knockout is available on most JavaScript platforms, or as a standalone script. Include as a script You can download the script from it's download page, then include it in your page with a standard script tag <script type='text/javascript' src='knockout-3.4.0.js'></script> Using a C...

knockout.js • Getting started with knockout.js

Linear regression on the mtcars dataset

The built-in mtcars data frame contains information about 32 cars, including their weight, fuel efficiency (in miles-per-gallon), speed, etc. (To find out more about the dataset, use help(mtcars)). If we are interested in the relationship between fuel efficiency (mpg) and weight (wt) we may start p...

R Language • Linear Models (Regression)

Use anonymous functions with apply

apply is used to evaluate a function (maybe an anonymous one) over the margins of an array or matrix. Let's use the iris dataset to illustrate this idea. The iris dataset has measurements of 150 flowers from 3 species. Let's see how this dataset is structured: > head(iris) Sepal.Length Sep...

R Language • *apply family of functions (functionals)

Array definition

Dim array(9) As Integer ' Defines an array variable with 10 Integer elements (0-9). Dim array = New Integer(10) {} ' Defines an array variable with 11 Integer elements (0-10) 'using New. Dim array As Integer() = {1, 2, 3, 4} ' Defines an Integer array variable a...

Visual Basic .NET Language • Array

Print statement vs. Print function

In Python 2, print is a statement: Python 2.x2.7 print "Hello World" print # print a newline print "No newline", # add trailing comma to remove newline print >>sys.stderr, "Error" # print to stderr print("hello"...

Python Language • Incompatibilities moving from Python 2 to Python 3

Installation and Setup

Prerequisites and Requirements for Magento Community Edition 1.9 Hosting Apache 2.x ( with mod_rewrite ) or Nginx 1.7.x Due to the demands of processing Magento operations, it is recommended that you install Magento on a server with at least 2 GB of RAM. This will ensure that all of the s...

magento • Getting started with magento

Installation or Setup

Windows If you have Visual Studio (any version including express and community) installed, F# should already be included. Just choose F# as the language when you create a new project. Or see http://fsharp.org/use/windows/ for more options. OS X Xamarin Studio supports F#. Alternately, you could u...

F# • Getting started with F#

Installation/Setup

Downloading: Download Bootstrap directly or clone, etc. from the GitHub repository Download your customized version of Bootstrap from official docs Install with bower: bower install bootstrap Install with npm: npm install bootstrap Install with composer: composer require twbs/bootstrap The...

twitter-bootstrap • Getting started with twitter-bootstrap

Function Arguments, "arguments" object, rest and spread parameters

Functions can take inputs in form of variables that can be used and assigned inside their own scope. The following function takes two numeric values and returns their sum: function addition (argument1, argument2){ return argument1 + argument2; } console.log(addition(2, 3)); // -> 5 ...

JavaScript • Functions

Arrays union, intersection and difference

x = [5, 5, 1, 3] y = [5, 2, 4, 3] Union (|) contains elements from both arrays, with duplicates removed: x | y => [5, 1, 3, 2, 4] Intersection (&) contains elements which are present both in first and second array: x & y => [5, 3] Difference (-) contains elements which ar...

Ruby Language • Arrays

Generic selection based on multiple arguments

If a selection on multiple arguments for a type generic expression is wanted, and all types in question are arithmetic types, an easy way to avoid nested _Generic expressions is to use addition of the parameters in the controlling expression: int max_int(int, int); unsigned max_unsigned(unsigned, ...

C Language • Generic selection

Installation or Setup

Windows PowerShell is included with the Windows Management Framework. Installation and Setup are not required on modern versions of Windows. Updates to PowerShell can be accomplished by installing a newer version of the Windows Management Framework. Other Platforms "Beta" version of P...

PowerShell • Getting started with PowerShell

Installation on Mac

The easiest way to set up NumPy on Mac is with pip pip install numpy Installation using Conda. Conda available for Windows, Mac, and Linux Install Conda. There are two ways to install Conda, either with Anaconda (Full package, include numpy) or Miniconda (only Conda,Python, and the package...

numpy • Getting started with numpy

Installation and Setup

Option 1: Leiningen Requires JDK 6 or newer. The easiest way to get started with Clojure is to download and install Leiningen, the de facto standard tool to manage Clojure projects, then run lein repl to open a REPL. Linux curl https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/l...

clojure • Getting started with clojure

Integer Division

The standard division symbol (/) operates differently in Python 3 and Python 2 when applied to integers. When dividing an integer by another integer in Python 3, the division operation x / y represents a true division (uses __truediv__ method) and produces a floating point result. Meanwhile, the ...

Python Language • Incompatibilities moving from Python 2 to Python 3

Installation or Setup

Getting setup with Spring Boot for the first time is quite fast thanks to the hard work of the Spring Community. Prerequisites: Java installed Java IDE Recommended not required (Intellij, Eclipse, Netbeans, etc.) You don't need to have Maven and/or Gradle installed. The projects generate...

spring-boot • Getting started with spring-boot