Tutorial by Examples: p

The zip function accepts 2 parameters of type SequenceType and returns a Zip2Sequence where each element contains a value from the first sequence and one from the second sequence. Example let nums = [1, 2, 3] let animals = ["Dog", "Cat", "Tiger"] let numsAndAnimals ...

stats::heatmap Example 1 (Basic usage) require(graphics); require(grDevices) x <- as.matrix(mtcars) rc <- rainbow(nrow(x), start = 0, end = .3) cc <- rainbow(ncol(x), start = 0, end = .3) hv <- heatmap(x, col = cm.colors(256), scale = "column", RowSideColo...

Compiler definitions run platform specific code. Using them you can make small differences between various platforms. Trigger Game Center achievements on apple devices and google play achievements on Android devices. Change the icons in menus (windows logo in windows, Linux penguin in Linux). P...

The mcparallelDo package allows for the evaluation of R code asynchronously on Unix-alike (e.g. Linux and MacOSX) operating systems. The underlying philosophy of the package is aligned with the needs of exploratory data analysis rather than coding. For coding asynchrony, consider the future packag...

defaultProps allows you to set default prop values for your component. In the below example if you do not pass the name props, it will display John otherwise it will display the passed value class Example extends Component { render() { return ( <View> <Text>{this...

What is an enter selection? In D3.js, when one binds data to DOM elements, three situations are possible: The number of elements and the number of data points are the same; There are more elements than data points; There are more data points than elements; In the situation #3, all the data ...

If you are behind a proxy, you have to tell git about it: git config --global http.proxy http://my.proxy.com:portnumber If you are no more behind a proxy: git config --global --unset http.proxy

Instances never contain a method they only carry data. However we can define a singleton class for any object including an instance of a class. When a message is passed to an object (method is called) Ruby first checks if a singleton class is defined for that object and if it can reply to that mess...

There are three ways to reopen a Singleton Class Using class_eval on a singleton class. Using class << block. Using def to define a method on the object's singleton class directly class Example end Example.singleton_class.class_eval do def foo :foo end end Example.fo...

By default Entity Framework maps decimal properties to decimal(18,2) columns in database tables. public class Box { public int Id { set; get; } public decimal Length { set; get; } public decimal Width { set; get; } public decimal Height { set; get; } } We can change the p...

A Semaphore is a high-level synchronizer that maintains a set of permits that can be acquired and released by threads. A Semaphore can be imagined as a counter of permits that will be decremented when a thread acquires, and incremented when a thread releases. If the amount of permits is 0 when a thr...

//all attributes $collection = Mage::getModel('catalog/product') ->getCollection() ->addAttributeToSelect('*'); //specific attributes $collection = Mage::getModel('catalog/product') ->getCollection() ->addAttributeToSelect('name'); //certain attributes are special...

$productFound = ($product->getId() !== null)

ValueConverted To StringConverted To NumberConverted To Booleanundefinded"undefined"NaNfalsenull"null"0falsetrue"true"1false"false"0NaN"NaN"false"" empty string0false" "0true"2.4" (numeric)2.4true"test" (non nu...

class base { }; class derived: public base { }; int main() { base* p = new derived(); delete p; // The is undefined behavior! } In section [expr.delete] §5.3.5/3 the standard says that if delete is called on an object whose static type does not have a virtual destructor: if the...

In C++ methods that differs only by const qualifier can be overloaded. Sometimes there may be a need of two versions of getter that return a reference to some member. Let Foo be a class, that has two methods that perform identical operations and returns a reference to an object of type Bar: class ...

A lot of users find themselves in a situation where they just want to copy, move or delete a line quickly and return to where they were. Usually, if you'd want to move a line which contains the word lot below the current line you'd type something like: /lot<Esc>dd<C-o>p But to boost...

This is a basic in-app keyboard. The same method could be used to make just about any keyboard layout. Here are the main things that need to be done: Create the keyboard layout in an .xib file, whose owner is a Swift or Objective-C class that is a UIView subclass. Tell the UITextField to use t...

This example adds a new rectangle to the canvas every 1 second (== a 1 second interval) Annotated Code: <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(functio...

This example animates a clock showing the seconds as a filled wedge Annotated Code: <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(function(){ // canva...