# Computing

Graph and its representations. Graph is a data structure that consists of following two components:1.

A finite set of vertices also called as nodes.2. A finite set of ordered pair of the form (u, v) called as edge. The pair is ordered because (u, v) is not same as (v, u) in case of directed graph(di-graph). The pair of form (u, v) indicates that there is an edge from vertex u to vertex v. The edges may contain weight/value/cost. Graphs are used to represent many real life applications: Graphs are used to represent networks. Cron format. Cron Format Cron format is a simple, yet powerful and flexible way to define time and frequency of various actions. nnCron make active use of cron format in both classic and extended modes.

Terminal 101: Creating Cron Jobs. Every Monday, we'll show you how to do something new and simple with Apple's built-in command line application.

You don't need any fancy software, or a knowledge of coding to do any of these. All you need is a keyboard to type 'em out! There are many times when you need to run a shell script or command at regular intervals. This can be to clean up your system or run maintenance tasks on your computer. For these jobs, you'll want to use something called "Crons.

" The Cron Job Syntax When specifying the time at which a cron runs, there is a specialized syntax that is used to tell the operating system exactly when to run the task. The timing sequence of a cron job looks like this: MySQL Database Export - Backup Methods. The simplest way of exporting a table data into a text file is using SELECT...INTO OUTFILE statement that exports a query result directly into a file on the server host.

Exporting Data with the SELECT ... INTO OUTFILE Statement: The syntax for this statement combines a regular SELECT with INTO OUTFILE filename at the end. The default output format is the same as for LOAD DATA, so the following statement exports the tutorials_tbl table into /tmp/tutorials.txt as a tab-delimited, linefeed-terminated file: mysql> SELECT * FROM tutorials_tbl -> INTO OUTFILE '/tmp/tutorials.txt'; You can change the output format using options to indicate how to quote and delimit columns and records. Polyglot.jl: transparent remote/recursive evaluation between languages. The Julia module Polyglot.jl supports transparent remote/recursive evaluation between Julia and another interpreter through automatic call serialization.

In poorer words, Polyglot.jl lets you call functions in other languages as they were regular Julia functions. It also allows other languages to call Julia functions as if they were native. Remote output is also transparently redirected locally, and since the evaluation is performed through a persistent co-process, you can actually spawn interpreters on different hosts through “ssh” efficiently. Polyglot.jl currently supports PHP, Perl, JavaScript (Node.js) and Python. Julia.

## JavaScript

D3. Python. C++ Xcode. Latex. Unix. Getting Started: Building a Chrome Extension. Extensions allow you to add functionality to Chrome without diving deeply into native code.

You can create new extensions for Chrome with those core technologies that you're already familiar with from web development: HTML, CSS, and JavaScript. If you've ever built a web page, you should feel right at home with extensions pretty quickly; we'll put that to the test right now by walking through the construction of a simple extension that will fetch an image from Google using the current page's URL as a search term.

We'll do so by implementing a UI element we call a browser action, which allows us to place a clickable icon right next to Chrome's Omnibox for easy access. Clicking that icon will open a popup window filled with an image derived from the current page, which will look something like this: Os_setup. Online Web Tutorials. Meta-meta. Free Online IDE and Terminal. Get started with Hadoop and Spark in 10 minutes. With the big 3 Hadoop vendors – Cloudera, Hortonworks and MapR - each providing their own Hadoop sandbox virtual machines (VMs), trying out Hadoop today has become extremely easy.

For a developer, it is extremely useful to download and get started with one of these VMs and try out Hadoop to practice data science right away. However, with the core Apache Hadoop, these vendors package their own software into their distributions, mostly for the orchestration and management, which can be a pain due to the multiple scattered open-source projects within the Hadoop ecosystem. e.g. Hortonworks includes the open-source Ambari while Cloudera includes its own Cloudera Manager for orchestrating Hadoop installations and managing multi-node clusters.

Moreover, most of these distributions require today a 64-bit machine and sometimes a high-amount of memory (for a laptop). e.g. running Cloudera Manager with a full-blown Cloudera Hadoop Distribution (CDH) 5.x requires at least 10GB RAM. Coding Tutorials. SQL Teaching - The easiest way to learn SQL. R inferno. Sublime Text: The text editor you'll fall in love with. DATA VISUALIZATION. Web Design Terminology: HTML vs CSS vs JavaScript etc. Big Data University. Compile and Execute Programs Online.