Tutorial by Examples: s

Most Rx operators take an optional scheduler on which to schedule their future iterations. If not supplied they will use their default configured scheduler. Supplying a scheduler can be useful for testing purposes in which we like to talk about virtual time instead of real time for speed of test exe...

Tuples are often used within collections but they must be handled in a specific way. For example, given the following list of tuples: scala> val l = List(1 -> 2, 2 -> 3, 3 -> 4) l: List[(Int, Int)] = List((1,2), (2,3), (3,4)) It may seem natural to add the elements together using im...

YAML supports three styles of escape notation: Entity Escapes a. space: " " b. colon: ":" c. ampersand: "&" Unicode Escapes a. space: "\u0020" b. single quote: "\u0027" c. double quote: "\u0022" ...

Use this to reset the table to the condition at which it was created. This deletes all rows and resets values such as auto-increment. It also doesn't log each individual row deletion. TRUNCATE TABLE Employees

Create a folder where you would like to have your game live, and move into that mkdir my-new-game cd my-new-game Initialize the directory using npm. npm init -y Install phaser as a node package. npm install phaser Install http-server as a global module, to be used on the...

With the Tap Gesture, you can make any UI-Element clickable (Images, Buttons, StackLayouts, ...): (1) In code, using the event: var tapGestureRecognizer = new TapGestureRecognizer(); tapGestureRecognizer.Tapped += (s, e) => { // handle the tap }; image.GestureRecognizers.Add(tapGestureR...

We have a set of jobs J={a,b,c,d,e,f,g}. Let j in J be a job than its start at sj and ends at fj. Two jobs are compatible if they don't overlap. A picture as example: The goal is to find the maximum subset of mutually compatible jobs. There are several greedy approaches for this problem: Earli...

Open a raster that covers the globe and extract a subset of the raster. import gdal # Path to a tiff file covering the globe # http://visibleearth.nasa.gov/view.php?id=57752 tif_name = "/path_name/land_shallow_topo_21600.tif" # Open raster in read only mode ds = gdal.Open(tif_n...

Matrix chain multiplication is an optimization problem that can be solved using dynamic programming. Given a sequence of matrices, the goal is to find the most efficient way to multiply these matrices. The problem is not actually to perform the multiplications, but merely to decide the sequence of t...

The HTML <p> element defines a paragraph: <p>This is a paragraph.</p> <p>This is another paragraph.</p> Display- You cannot be sure how HTML will be displayed. Large or small screens, and resized windows will create different results. With HTML, you cannot chang...

In the view file In the base html (index.html) where we usually include the angular scripts or the html that is shared across the app, leave an empty div element, the flash messages will be appearing inside this div element <div class="flashmessage" ng-if="isVisible"> ...

In order to create a scheduler,the entry needs to be created in liferay-portlet.xml provding scheduler class and trigger value for timing of scheduler triggering <portlet-name>GetSetGo</portlet-name> <icon>/icon.png</icon> <scheduler-entry> ...

There are numerous problems minimizing lateness, here we have a single resource which can only process one job at a time. Job j requires tj units of processing time and is due at time dj. if j starts at time sj it will finish at time fj=sj+tj. We define lateness L=max{0,fj-dh} for all j. The goal is...

Dependencies: GNU Make Version > 3.80 an ISO/ ANSI C-Compiler (e.g. gcc) an extractor like tar or gzip zlib-devel readline-devel oder libedit-devel Sources: Link to the latest source (9.6.3) Now you can extract the source files: tar -xzvf postgresql-9.6.3.tar.gz There are a large ...

CREATE [OR REPLACE] FUNCTION functionName (someParameter 'parameterType') RETURNS 'DATATYPE' AS $_block_name_$ DECLARE --declare something BEGIN --do something --return something END; $_block_name_$ LANGUAGE plpgsql;

Options for returning in a PL/pgSQL function: Datatype List of all datatypes Table(column_name column_type, ...) Setof 'Datatype' or 'table_column'

Part I : Setup the Mac machine to use shenzhen Go to terminal Install Shenzhen sudo gem install shenzhen sudo gem install nomad-cli Download XCode command line utility xcode-select --install Popup shows up with the below text The xcode-select command requires the command line d...

Computed properties will automatically be recomputed whenever any data on which the computation depends changes. However, if you need to manually change a computed property, Vue allows you to create a setter method to do this: Template (from the basic example above): <div id="example"...

Ruby 2.3.0 added the safe navigation operator, &.. This operator is intended to shorten the paradigm of object && object.property && object.property.method in conditional statements. For example, you have a House object with an address property, and you want to find the street_n...