Tutorial by Examples: i

Correctly appending an SVG element

This is a relatively common mistake: You created an rect element, in a bar chart for instance, and you want to add a text label (let's say, the value of that bar). So, using the same variable that you used to append the rect and define its x and y position, you append your text element. Very logic, ...

d3.js • Core SVG concepts used in D3.js visualization

Tensorflow Basics

Tensorflow works on principle of dataflow graphs. To perform some computation there are two steps: Represent the computation as a graph. Execute the graph. Representation: Like any directed graph a Tensorflow graph consists of nodes and directional edges. Node: A Node is also called an Op(s...

tensorflow • Getting started with tensorflow

pushd/popd (store current dir on stack and go to dest / pop prev dir and go to it)

$ pwd /home/bob/somedir1/somedir2/somedir3 $ pushd /home/bob/otherdir1/otherdir2 /home/bob/otherdir1/otherdir2 /home/bob/somedir1/somedir2/somedir3 $ popd /home/bob/somedir1/somedir2/somedir3 $ pushd /usr /usr /home/bob/somedir1/somedir2/somedir3 $ pushd /var /var /usr /home/bob/som...

unix • Basic console commands

Repeat a String

6 This can be done using the .repeat() method: "abc".repeat(3); // Returns "abcabcabc" "abc".repeat(0); // Returns "" "abc".repeat(-1); // Throws a RangeError 6 In the general case, this should be done using a correct polyfill for the ES6...

JavaScript • Strings

Function compositions with multiple channels

Arrow is, vaguely speaking, the class of morphisms that compose like functions, with both serial composition and “parallel composition”. While it is most interesting as a generalisation of functions, the Arrow (->) instance itself is already quite useful. For instance, the following function: sp...

Haskell Language • Arrows

Semantics of typed holes

The value of a type hole can simply said to be undefined, although a typed hole triggers a compile-time error, so it is not strictly necessary to assign it a value. However, a typed hole (when they are enabled) produces a compile time error (or warning with deferred type errors) which states the nam...

Haskell Language • Typed holes

Using rewrite rules on overloaded functions

In this question, @Viclib asked about using rewrite rules to exploit typeclass laws to eliminate some overloaded function calls: Mind the following class: class ListIsomorphic l where toList :: l a -> [a] fromList :: [a] -> l a I also demand that toList . fromList == id. H...

Haskell Language • Rewrite rules (GHC)

What is Entity Framework ?

Writing and managing ADO.Net code for data access is a tedious and monotonous job. Microsoft has provided an O/RM framework called "Entity Framework" to automate database related activities for your application. Entity framework is an Object/Relational Mapping (O/RM) framework. It is an e...

Entity Framework • Getting started with Entity Framework

Enumerating the Enumerable

The IEnumerable<T> interface is the base interface for all generic enumerators and is a quintessential part of understanding LINQ. At its core, it represents the sequence. This underlying interface is inherited by all of the generic collections, such as Collection<T>, Array, List<T&g...

C# Language • LINQ Queries

In-line DIV using float

The div is a block-level element, i.e it occupies the whole of the page width and the siblings are place one below the other irrespective of their width. <div> <p>This is DIV 1</p> </div> <div> <p>This is DIV 2</p> </div> The output of...

CSS • Floats

Creating a Seeder

To create seeders, you may use the make:seeder Artisan command. All seeders generated will be placed in the database/seeds directory. $ php artisan make:seeder MoviesTableSeeder Generated seeders will contain one method: run. You may insert data into your database in this method. <?php us...

Laravel • Seeding

Existential Operator

CoffeeScript's existential operator ? check if the variable is null or undefined. 1. Check for null or undefined. alert "Hello CoffeeScript!" if myVar? javascript equivalent: if (typeof myVar !== "undefined" && myVar !== null) { alert("Hello CoffeeScript!&qu...

coffeescript • Operators

Partially update the view

Makes an ajax request and updates only part of the view. Bean.java @ManagedBean @ViewScoped public class Bean { public Date getCurrentDate() { return new Date(); } } sample.xhtml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://xmlns...

jsf • Ajax Integration

Send form parts and listen to the request

Makes a request only sending part of the form. The text1 value is set, but not text2, as the listener states. Bean.java @ManagedBean @ViewScoped public class Bean { private String text1; private String text2; public String getText1() { return text1; } pu...

jsf • Ajax Integration

Ajax on javascript event

The date is updated whenever user types on the input field: Bean.java @ManagedBean @ViewScoped public class Bean { public Date getCurrentDate(){ return new Date(); } } sample.xhtml <html xmlns="http://www.w3.org/1999/xhtml" xmlns:h="http://x...

jsf • Ajax Integration

Switch to a frame using C#

1. Switch to a frame by Index. Here we are switching to index 1. Index refers to the order of frames on the page. This should be used as a last resort, as frame id or names are much more reliable. driver.SwitchTo().Frame(1); 2. Switch to a frame by Name driver.SwitchTo().Frame("Name_Of_Fr...

selenium-webdriver • Switching Frames

Automatically processing data received from a serial port

Some devices connected through a serial port send data to your program at a constant rate (streaming data) or send data at unpredictable intervals. You can configure the serial port to execute a function automatically to handle data whenever it arrives. This is called the "callback function&quo...

MATLAB Language • Using serial ports

Convenient in-model sanitizing

Set a convenience method in your base model namespace Base; class Model extends \Phalcon\Mvc\Model { public function sanitize($attr, $filterName) { $filter = $this->getDI()->get('filter'); $this->$attr = $filter->sanitize($this->$attr, $filterName); ...

phalcon • Filtering and Sanitizing

Local Type Inference

Scala has a powerful type-inference mechanism built-in to the language. This mechanism is termed as 'Local Type Inference': val i = 1 + 2 // the type of i is Int val s = "I am a String" // the type of s is String def squared(x : Int) = x*x // the return type ...

Scala Language • Type Inference

Type Inference And Generics

The Scala compiler can also deduce type parameters when polymorphic methods are called, or when generic classes are instantiated: case class InferedPair[A, B](a: A, b: B) val pairFirstInst = InferedPair("Husband", "Wife") //type is InferedPair[String, String] // Equiv...

Scala Language • Type Inference