Tutorial by Examples: en

Viridis (named after the chromis viridis fish) is a recently developed color scheme for the Python library matplotlib (the video presentation by the link explains how the color scheme was developed and what are its main advantages). It is seamlessly ported to R. There are 4 variants of color scheme...

Take a use case, like a chat app or a collaborative grocery list app (that basically requires a list of objects to be synced across users). If you use firebase database and add a value event listener to the chat parent node or grocery list parent node, you will end with entire chat structure from th...

When we put the control of Label, the Label does not provide any event. <Label x:Name="lblSignUp Text="Dont't have account?"/> as shown the Label only display purpose only. When the user want to replace Button with Label, then we give the event for Label. As shown below: XA...

Magento is a very popular eCommerce application. It offers a great deal of customization and abilities from initial install. Here are a few suggestions for optimizing a Magento installation. Enabling Output Compression In your .htaccess file for Magento you will find a section of text starting wit...

First-time visitors to any web page has to make several HTTP requests. By using the “Expires” header you make the components of the requests cacheable. This avoids unnecessary HTTP requests on subsequent page views. You want to find the area of the .htaccess file that starts with <IfModulemod_ex...

The model Magento uses to store customer and product data results in longer than average SQL queries and more reads. Enabling the Flat Catalog option for Categories and Products will merge product data into one table, therefore improving performance. Login to your administration area and go to – Sy...

Login to your administration area and go to – System > Cache Management Next, click on the Select All link Finally, make sure the Actions is set to Enable and click submit Disable Error Logging Login to your administration area and go to – System > Configuration > Developer Under ...

The task is to find the length of the longest subsequence in a given array of integers such that all elements of the subsequence are sorted in ascending order. For example, the length of the longest increasing subsequence(LIS) for {15, 27, 14, 38, 26, 55, 46, 65, 85} is 6 and the longest increasing ...

Controller::renderAjax() method can be used to respond to an Ajax request. This method is similar to renderPartial() except that it will inject into the rendering result with JS/CSS scripts and files which are registered with the view Assume we have login form in a view file: <?php use yii\hel...

Given a string what is the longest palindromic subsequence(LPS) of it? Let's take a string agbdba. The LPS of this string is abdba of length 5. Remember, since we're looking for subsequence, the characters need not to be continuous in the original string. The longest palindromic substring of the seq...

This chapter describes how to set up a Docker Container with Jenkins inside, which is capable of sending Docker commands to the Docker installation (the Docker Daemon) of the Host. Effectively using Docker in Docker. To achieve this, we have to build a custom Docker Image which is based on an arbitr...

This is an example of a web-socket client in javascript. It: Connects to a live demo server. Sends a message. Receives message(s). Disconnects after an interval. var mySocket = null; var serverUrl = 'wss://echo.websocket.org'; // wss: is ws: but using SSL. var oWebSocket = window...

In JSX expressions that contain both an opening tag and a closing tag, the content between those tags is passed as a special prop: props.children. There are several different ways to pass children: String Literals You can put a string between the opening and closing tags and props.children will ju...

Fluent wait is a superclass of explicit wait (WebDriverWait) that is more configurable since it can accept an argument to the wait function. I'll pass on implicit wait, since it's a best practice to avoid it. Usage (Java): Wait wait = new FluentWait<>(this.driver) .withTimeout(drive...

This error message may be produced by the OpenSSH ssh client. It means that the TCP connection between the client and the server was abnormally closed by the server immediately after being accepted. Common reasons for this message include: The SSH server process is malfunctioning--for example, it...

This error message may be produced by the OpenSSH ssh client. It means that the TCP connection between the client and the server was closed by the server immediately after being accepted. This message generally indicates the SSH server has been configured not to accept connections from the client fo...

$ rails g job user_unsubscribe

To compare the difference of two dates, we can do the comparison based on the timestamp. var date1 = new Date(); var date2 = new Date(date1.valueOf() + 5000); var dateDiff = date1.valueOf() - date2.valueOf(); var dateDiffInYears = dateDiff/1000/60/60/24/365; //convert milliseconds into years ...

There is no imshow in the java, you need to write a method for this. This method is a Mat2bufferedImage. Takes mat object as parameter and returns image. public static void main(String[] args) { Mat frame = new Mat(); //0; default video device id VideoCapture camera = new VideoCaptur...

Spotify currently hosts documentation for all its third-party developer tools on its Developer Site.