MongoDB Summation vs Count Query

In MongoDB, when you want to summate a key, you need to distinguish from summating and counting. The below examples try to illustrate the differences: Summate »

Comparison: Apple iPhone 6 Plus vs Samsung Galaxy S6

I am using mobile phones since 1995 and discovered SMS with my friends and even teached Vodafone Support staff about the SMS technology. I owned a »

Testing Angular's $http module and its promises

When I started Unit Testing my Angular Services, I faced certain difficulties originating in not understanding completely how the $http module and promises in Angular worked »

CoffeeScript Techniques

List Comprehensions Very Python-y technique I use on a daily basis: for k,v of myList console.log('%s has %s', key, value) How to »

How to install syncthing on Ubuntu Server

After nuking my Ubuntu 12.04 server and installing 14.04, I could finally use the ppa. The whole installation experience was a huge let down »

Mixpanel Integration with Ghost

Until the API and APP/Plugin Dev Process gets sorted out I have simply forked the Ghost project and implemented the feature I needed. Download You »

SSH and git through that socks proxy

In case you want to git and ssh trough an socks proxy at work or another environment on a Mac or on a Linux client you »

Isomorphic JavaScript Frameworks compared

Isomorphic What? Client MVC The bulk of the application logic (views, templates, controllers, models, internationalization, etc.) lives in the client, and it talks to an API »

Continuous Integration with grunt, node and yeoman angular-fullstack

In case you use the excellent angular-fullstack generator, have build your app and now are ready to deploy you will most likely face certain obstacles: How »

Server-Side Pagination and Filtering with Angular and MongoDB

I am trying to get Server-Side Queries to work. I am using the excellent trNgGrid to accomplish this. If you don't know it yet, it is »

Angular Workflow with Node, Yeoman, Grunt and Bower.

Introduction Why such Workflow Classical Web Development Hands-On Tutorial Grunt Node Yeoman Installing Node.js Installing Yeoman, Grunt, Bower Use Yeoman the first time Starting Grunt »

Nginx: connect () to unix: /var/run/php5-fpm.sock failed (13: Permission denied)

The error log of the nginx web server quickly revealed the original error: $ sudo tail /var/log/nginx/error.log 10.22.2014 07:29:11 »

404 Not Found - What's up with ?

We are back — faster, bigger & enthusiastic We apologise the inconveniences in the last few weeks, but we have experienced a hard disk corruption and needed »

How to drop the Ghost posts table?

I am using last years version of Ghost. Now I need to drop parts of my Ghost database, the posts tables, posts_tags table and tags »

Mongoose: Exclude fields to return from Query

In case you want to use MongoDB .exclude methods on your model within Mongoose, but you don't want to abandon native Mongoose and its benefits, starting »

Review: Fostex TH-600

After years and months of reading and listening through Sennheiser HD 25 SP II (2007-now) Sony IEMs (2012-now) Sennheiser Momentum (2014 sold) Beyerdynamic DT 1350 (2010-2014 »

Proof Systems

An argument is inferable, if and only if there exists no interpretation in which the premises are True and the conclusion False. Justified Argument From a »

Elastic Map Reduce with Amazon S3, AWS, EMR, Python, MrJob and Ubuntu 14.04

This tutorial is about setting up an environment with scripts to work via Amazon's Hadoop implmentation EMR on huge datasets. With dataset I mean extremely large »

Computational thinking

One can major in computer science and go on to a career in medicine, law, business, politics, any type of science or engineering, and even the »

Access a BlackBerry Q10 on Ubuntu 14.04

This is a tutorial on howto access a BlackBerry Q10 or Z10 business smartphone on Ubuntu 14.04 or any other Linux or MacOSX. You will »

Hash Tables

Hash tables are for searching what binary trees are for sorting. Hash table data structures can reduce time complexity down to O(1), a linear order »

Computational Complexity

Instead of analysing the complexity of a given algorithm, e.g. Bubble Sorts complexity of O(n²) or Heap Sort's complexity of O(n log n »

Decidability of Computational Problems

A famous decision problem is Alan Turing's halting problem. But first we have to understand how a computational problem can be defined as mathematical function. Computational »

Binary Search Trees

A tree has the following properties: One root node Every node is connected by one edge with another node, except the root node A unique path »


This is an article about sorting and the classic ways on how to achieve it in computer science. Bubble Sort Bubble sort was invented by Edward »