Tutorial by Examples: ga

<svg width="900px" height="400px" viewBox="900 400"> <defs> <filter id="GaussianHardEdge" x="0%" y="0%" width="100%" height="100%"> <feGaussianBlur stdDeviation="5"/&gt...

<svg width="800px" height="600px"> <defs> <filter id="focus-blur" > <feDiffuseLighting result = "diffOut" diffuseConstant = "1" lighting-color="white"> <feSpotLight id="spotlight" x =...

Elasticsearch is accessed through a HTTP REST API, typically using the cURL library. The messages between the search server and the client (your or your application) are sent in the form of JSON strings. By default, Elasticsearch runs on port 9200. In the examples below, ?pretty is added to tell El...

// Get the current colors of the gradient. let oldColors = self.gradientLayer.colors // Define the new colors for the gradient. let newColors = [UIColor.red.cgColor, UIColor.yellow.cgColor] // Set the new colors of the gradient. self.gradientLayer.colors = newColors // Initia...

open(my $fh, '<', "/some/path") or die $!; my @ary = <$fh>; When evaluated in list context, the diamond operator returns a list consisting of all the lines in the file (in this case, assigning the result to an array supplies list context). The line terminator is retained, and ...

To load an image and place it on the canvas var image = new Image(); // see note on creating an image image.src = "imageURL"; image.onload = function(){ ctx.drawImage(this,0,0); } Creating an image There are several ways to create an image new Image() document.createEleme...

Suppose we want to get all product categories with total sales greater than 20. Here is a query without Common Table Expressions: SELECT category.description, sum(product.price) as total_sales FROM sale LEFT JOIN product on sale.product_id = product.id LEFT JOIN category on product.category_id ...

perl -ne'print if /foo/' file.txt Case-insensitive: perl -ne'print if /foo/i' file.txt

Adding components one after another results in a UI that's hard to use, because the components all are somewhere. The components are ordered from top to bottom, each component in a separate "row". To remedy this and provide you as developer with a possibility to layout components easily S...

Margin is one of a few CSS properties that can be set to negative values. This property can be used to overlap elements without absolute positioning. div{ display: inline; } #over{ margin-left: -20px; } <div>Base div</div> <div id="over">Overlapping div&lt...

genRandom creates a stream of random numbers that has a one in four chance of terminating each time it's called. def genRandom: Stream[String] = { val random = scala.util.Random.nextFloat() println(s"Random value is: $random") if (random < 0.25) { Stream.empty[String] ...

You'll need to separate out your application layer from your database layer, and that means specifying the MONGO_URL. Which means running your app through the bundle command, uncompressing it, setting environment variables, and then launching the project as a node app. Here's how... #make sure you...

The replica set will need an oplog user to access the database. mongo PRIMARY> use admin PRIMARY> db.addUser({user:"oplogger",pwd:"YOUR_PASSWORD",roles:[],otherDBRoles:{local:["read"]}}); PRIMARY> show users

There's two great utilities for black-box analysis of databases. First is variety.js, which will give you a high-level overview. The second is schema.js, which will let you dig into the collections for more detail on the individual fields. When inheriting a production Mongo database, these two util...

Mongo supports database-to-database copying, which is useful if you have large databases on a staging database that you want to copy into a local development instance. // run mongod so we can create a staging database // note that this is a separate instance from the meteor mongo and minimongo ins...

Purpose Use the CREATE SEQUENCE statement to create a sequence, which is a database object from which multiple users may generate unique integers. You can use sequences to automatically generate primary key values. When a sequence number is generated, the sequence is incremented, independent of th...

If you are just starting a new project, it's important to think about how you want to handle code signing. If you are new to code signing, check out the WWDC session that describes the fundamentals of code signing in Xcode. To properly code-sign your app, you have to have the following resources o...

If you want to add all the JARs in directory to the classpath, you can do this concisely using classpath wildcard syntax; for example: someFolder/* This tells the JVM to add all JAR and ZIP files in the someFolder directory to the classpath. This syntax can be used in a -cp argument, a CLASSPA...

NSAttributedString (and its mutable sibling NSMutableAttributedString) allows you to create strings that are complex in their appearance to the user. A common application is to use this to display a string and adding custom kerning / letter-spacing. This would be achieved as follows (where label ...

Simply use the .ToString overload of a DateTime object to get the format you require: Dim dateValue As DateTime = New DateTime(2001, 03, 06) Dim dateString As String = dateValue.ToString("yyyy-MM-dd") '2001-03-06