Tutorial by Examples: r

Angular js directives can be nested or be made interoperable. In this example, directive Adir exposes to directive Bdir it's controller $scope, since Bdir requires Adir. angular.module('myApp',[]).directive('Adir', function () { return { restrict: 'AE', controlle...

enum Util { /* No instances */; public static int clamp(int min, int max, int i) { return Math.min(Math.max(i, min), max); } // other utility methods... } Just as enum can be used for singletons (1 instance classes), it can be used for utility classes (0 instance...

Imagine that we have a class Math.php with logic of calculating of fiobanacci and factorial numbers. Something like this: <?php class Math { public function fibonacci($n) { if (is_int($n) && $n > 0) { $elements = array(); $elements[1] = 1; ...

install the required Microsoft.SqlServer.Types assembly; they are not installed by default, and are available from Microsoft here as "Microsoft® System CLR Types for Microsoft® SQL Server® 2012" - note that there are separate installers for x86 and x64. install Dapper.EntityFramew...

Once the type handlers are registered, everything should work automatically, and you should be able to use these types as either parameters or return values: string redmond = "POINT (122.1215 47.6740)"; DbGeography point = DbGeography.PointFromText(redmond, DbGeography.DefaultCoordi...

When using Access you can retrieve data using queries. These queries are built using Structured Query Language (SQL). Understanding SQL is important because it can help build better, more useful queries. When creating queries in Access, you can switch to "SQL View". An example of a "...

When you wish to combine the results of multiple tables or queries with similar fields together into a single resulting data set without performing any relational joins (i.e. you want to list one dataset immediately after the other), you will use a UNION query. However, it is notable that these quer...

The BOM (Browser Object Model) contains objects that represent the current browser window and components; objects that model things like history, device's screen, etc The topmost object in BOM is the window object, which represents the current browser window or tab. Document: represents current...

An awk consists of patterns and actions, enclosed in curly brackets, to be taken if a pattern matches. The most basic pattern is the empty pattern, which matches any record. The most basic action is the empty action, which is equivalent to { print }, which is, in turn, equivalent to { print $0 }. If...

The http_build_query() will create a query string from an array or object. These strings can be appended to a URL to create a GET request, or used in a POST request with, for example, cURL. $parameters = array( 'parameter1' => 'foo', 'parameter2' => 'bar', ); $queryString = http_b...

Basic usage If the value of the href-attribute begins with mailto: it will try to open an email client on click: <a href="mailto:[email protected]">Send email</a> This will put the email address [email protected] as the recipient for the newly created email. Cc and ...

At the command prompt: $ echo "Hello World" Output: Hello World To create a script, create a text document with the following content: #!/bin/sh echo "Hello World" Save the script with the name hello.sh (or any filename) and make the script executable by giving the f...

<PropertyGroup> <!-- Definition of a Property named "TestCondition". A PropertyGroup may also be placed inside a Target. --> <TestCondition>True</TestCondition> </PropertyGroup> <!-- This Target will run after the "Clean" Target, su...

We can read from a text file: dt <- fread("my_file.csv") Unlike read.csv, fread will read strings as strings, not as factors by default. See the [topic on fread][need_a_link] for more examples.

For efficiency, data.table offers a way of altering a data.frame or list to make a data.table in-place: # example data.frame DF = data.frame(x = letters[1:5], y = 1:5, z = (1:5) > 3) # modification setDT(DF) Note that we do not <- assign the result, since the object DF has been modifi...

# example data DT1 = data.table(x = letters[1:2], y = 1:2, z = (1:2) > 3) Due to the way data.tables are manipulated, DT2 <- DT1 will not make a copy. That is, later modifications to the columns or other attributes of DT2 will affect DT1 as well. When you want a real copy, use DT2 = copy(...

# example data DT = data.table(Titanic) Suppose we only want to see second class: DT[ Class == "2nd" ] # Class Sex Age Survived N # 1: 2nd Male Child No 0 # 2: 2nd Female Child No 0 # 3: 2nd Male Adult No 154 # 4: 2nd Female Adult ...

# example data DT = data.table(Titanic) Suppose we want to see each class only if a majority survived: DT[, if (sum(N[Survived=="Yes"]) > sum(N[Survived=="No"]) ) .SD, by=Class] # Class Sex Age Survived N # 1: 1st Male Child No 0 # 2: 1st Fema...

Match (node_name:node_type {}), (node_name_two:node_type_two {}) CREATE (node_name)-[::edge_name{}]->(node_name_two)

A quick note before actually installing RabbitMQ: Ubuntu 14.04's Erlang packages have issues if you are using SSL with RabbitMQ, so you'll need to install a newer version than what the Ubuntu package maintainers provide, so use the binaries at https://www.erlang-solutions.com/resources/download.html...