## Graph Coloring Problem

A node coloring is valid or admissible if any two adjacent nodes do not have the same color. If a graph is colorable, there is a smallest number such that the graph is node colorable. This number is called the chromatic number of the graph and is usually denoted by . The problem to identify… Read more Graph Coloring Problem

## Neopixels with micro:bit

In this post I will demonstrate a “Hello, World!” example for the micro:bit to light up some Neopixels. Neopixels are individually-addressable RGB LEDs and can come in various forms. The most common form is the chain having all units connected serially. It was invented by Adafruit, an open-source hardware company based in New York City. Why did I… Read more Neopixels with micro:bit

## Solving a TSP with Linear Programming and Google OR-Tools in Python

In this post I show you how to solve the TSP problem using integer linear programming and Google OR-Tools for mathmatical modelling in Python. If you’re not yet familiar to the TSP and want to dig deeper, find out more here. It is one of the oldest and best explored problems in the field of… Read more Solving a TSP with Linear Programming and Google OR-Tools in Python

## Happy Birthday Duino

In this post I’ll show you the simplest setup to generate synthetic sound using an Arduino Pro Mini. Of course you can also run it on a Leonardo or on an Arduino UNO R3. The project is inspired from a project from the official arduino project hub and you can get the sourcecode here. What… Read more Happy Birthday Duino

## TSP Miller-Tucker-Zemlin Subtour Elimination Constraint

In this post we want to try to provide a solution to solve the Traveling Salesman Problem (TSP) using linear programming. The post is based on this excellent video from Mr. Michel Bierlaire at the EPFL. A good written documentation of the Miller Tucker Zemlin Constraint can be found here. What is a TSP? The… Read more TSP Miller-Tucker-Zemlin Subtour Elimination Constraint

## Graph Modelling Tool

In this post I’d like to introduce you to a cool webbased tool to visualize directed or undirected graphs. It is hosted at csacademy.com and can be found here. The following image shows a potential solution to the TSP problem with 5 locations, when the subtour elimination constraint is not considered. In order to generate… Read more Graph Modelling Tool

## An Arduino based Math Trainer

In this post I’ll show you how to build an arduino based math training console based on simple standard components. The app is suitable for training math in lower and middle school. It allows configuring difficulty level as well as operations and lets the player choose the correct result from a selection of 4 outcomes… Read more An Arduino based Math Trainer

## Deploy Python UI Apps including Java Business-Logic

In this post you’ll learn how to deploy a python application in the form of a directory which can be distributed as an archive or as a single executable file. This is the last of three posts on a series about UI development in python embedding Java based business logic and shows you a concept,… Read more Deploy Python UI Apps including Java Business-Logic

## Embedding Java Logic into a Python Application

In this post I’ll demonstrate how to embed logic provided by a java application into a python PyQt5 UI based application. The motivation for this project arose from the need to be able to port legacy code in the form of an old Eclipse Rich Client Platform application to a contemporary technology with as little… Read more Embedding Java Logic into a Python Application

## Fast UI-Prototyping in Python using PyQt5 Designer

In this post I demonstrate how easy it is to design user interfaces with PyQt5 Designer. We’ll design a simple UI, which allows to add two numbers. Because I often have to develop scientific applications in my job, I regularly face the challenge of developing simple GUIs. There are hundreds of solutions, web- or fat-client… Read more Fast UI-Prototyping in Python using PyQt5 Designer