General

There are only 3 Programming Paradigms!!!

If we think of programming as a general concept for expressing problems in terms of an Input/Output system and by what is given, then three general paradigms can be differentiated. Interestingly these “paradigms” seem to directly match the three different concepts of philosophical reasoning. 1. Imperative Programming & Deduction This first (and mostly applied) paradigm…

General

Converting an IPython Notebook to PDF

This is just a simple workaround that I found after hours of trying to convert an ipython notebook into a pdf, which also contains all markdown images and scales them acordingly. Well, the solution to this was acutally quite simple. Do not try to make use of the web interface, do not convert it to…

C & C++

Birds Eye View / Homography using OpenCV

When I looked for a small example for a homography transformation using OpenCV in order to provide a birds eye projection of an image. I did not find an appropriate ones, hence, I combined a number of motivating introductions and code fragments in an illustrative small program. It can be adapted for your actual purpose…

Python

Bidirectional Graph-Search: A Benchmark

A Bidirectional Graph-Search Algorithm We had some trouble with the slow identification of “simple paths” and “shortest paths” in our application, whereby we applied the common networkx library for python. We therefore developed our own bidirectional path search algorithms, for which we want provide a small benchmark at this post. The algorithms can be downloaded…

C & C++

Installing OpenRAVE0.9 on Ubuntu trusty (14.04)

Finally I made it… compile OpenRAVE under Ubuntu trusty and to run it without getting this segmentation fault: undefined symbol: _ZN5boost20assertion_failed_msgEPKcS1_S1_S1_l In fact it is pretty simple, here is what I did: Download the latest OpenRAVE version from the git repository, as described at the website below git clone –branch latest_stable https://github.com/rdiankov/openrave.git It is also…

Matlab

Matlab – 3D bars arrays without empty elements

bar3 is an useful command to illustrate multi-dimensional distributions. If the colors of the beams represent its value, the diagram gives a good overview. But the code examples given in the Matlab help work just fine for matrices without “0” elements. The following figure shows a bar3 diagram that includes values from 0 to 7….