Tutorial by Examples: r

Following are the Prerequisites for installing Cookiecutter: pip virtualenv PostgreSQL Create a virtualenv for your project and activate it: $ mkvirtualenv <virtualenv name> $ workon <virtualenv name> Now install Cookiecutter using: $ pip install cookiecutter Change dire...

This example finds a point on a bezier or cubic curve at position where position is he unit distance on the curve 0 <= position <= 1. The position is clamped to the range thus if values < 0 or > 1 are passed they will be set 0,1 respectively. Pass the function 6 coordinates for quadrati...

Unlike most other JavaScript objects, symbols are not automatically converted into a string when performing concatenation. let apple = Symbol('Apple') + ''; // throws TypeError! Instead, they have to be explicitly converted into a string when necessary, (for example, to get a textual description...

Server-Side JavaScript Native JSON Samplestack Sample Application Temporal Documents REST Management API Improvements More Semantics Features, Including SPARQL 1.1, Inferencing, and SPARQL UPDATE Node.js Client API REST and Java Client API Improvements Enhanced HTTP Server Features Flexi...

The Symbol.for method allows you to register and look up global symbols by name. The first time it is called with a given key, it creates a new symbol and adds it to the registry. let a = Symbol.for('A'); The next time you call Symbol.for('A'), the same symbol will be returned instead of a new o...

For more complex applications, flat execution profiles may be difficult to follow. This is why many profiling tools also generate some form of annotated callgraph information. gperf2dot converts text output from many profilers (Linux perf, callgrind, oprofile etc.) into a callgraph diagram. You can...

Google Perf Tools also provides a CPU profiler, with a slightly friendlier interface. To use it: Install Google Perf Tools Compile your code as usual Add the libprofiler profiler library to your library load path at runtime Use pprof to generate a flat execution profile, or a callgraph diagram...

The | can be used to have a single case statement match against multiple inputs to yield the same result: def f(str: String): String = str match { case "foo" | "bar" => "Matched!" case _ => "No match." } f("foo") // res0: String = M...

Given the following List of tuples: val pastries = List(("Chocolate Cupcake", 2.50), ("Vanilla Cupcake", 2.25), ("Plain Muffin", 3.25)) Pattern matching can be used to handle each element differently: pastries foreach { pa...

Bootstrapping Magento by calling: require_once 'app/Mage.php'; Mage::app(); // Your code This is the simplest way but not really the Magento way because we're not using class that extends Mage_Shell_Abstract - the class which when extended provides us with tools to parse command line arguments...

Magento way File resides in shell/custom.php <?php require_once' abstract.php'; class Stackoverflow_Shell_Custom extends Mage_Shell_Abstract { protected $_argname = array(); public function __construct() { parent::__construct(); // Time limit to infinity ...

The std::nth_element algorithm takes three iterators: an iterator to the beginning, nth position, and end. Once the function returns, the nth element (by order) will be the nth smallest element. (The function has more elaborate overloads, e.g., some taking comparison functors; see the above link for...

.exr -1 gives you details about the last exception thrown. !analyze -v usually does a good job as well. For .NET, the command !pe of the SOS extension shows details about the .NET exception that was thrown.

Hosted XSLT 2.0 Setup To run XSLT 2.0 in the browser, use one of the following XSLT 2.0 as a service hosts: XSLT Fiddle W3C XSLT Servlet Online XSLT Test Tool

An incomplete list of WinDbg extensions that are not installed with WinDbg itself: ExtensionPurposeSOS.NET (official Microsoft extension)SOSex.NET (extension for SOS)CoSOS.NET (extension for SOS)NetExt.NET (with focus on networking)PyKDPython scriptingPDEWindows native and store applications (stowe...

Ref returns and ref locals are useful for manipulating and returning references to blocks of memory instead of copying memory without resorting to unsafe pointers. Ref Return public static ref TValue Choose<TValue>( Func<bool> condition, ref TValue left, ref TValue right) { ...

The keyword partial can be used during type definition of class, struct, or interface to allow the type definition to be split into several files. This is useful to incorporate new features in auto generated code. File1.cs namespace A { public partial class Test { public string...

We're going to use the expression tree API to create a CalculateSalesTax tree. In plain English, here's a summary of the steps it takes to create the tree. Check if the product is taxable If it is, multiply the line total by the applicable tax rate and return that amount Otherwise return 0 ...

Sometimes we want to look at what is sent and received in the SOAP request. The following methods will return the XML in the request and response: SoapClient::__getLastRequest() SoapClient::__getLastRequestHeaders() SoapClient::__getLastResponse() SoapClient::__getLastResponseHeaders() For ex...

When static_cast is used to convert T D::* to T B::*, the member pointed to must belong to a class that is a base class or derived class of B. Otherwise the behavior is undefined. See Derived to base conversion for pointers to members