Have you ever wanted to test some hypothesis or constructions involving (weakly) connected directed graphs? In that case, it can be quite resource consuming to generate canonically labelled representatives as you go, for instance, in sage. Furthermore, there is a good chance that you are going to need the representatives again and again. After having spent my fair share of computing power to generate these representatives, I went hunting for an online database where I could just download them — but I did not find any. So I created such a database myself using sage, possibly saving you around 12 hours of computations (see: github.com/immanuel-albrecht/databases).
The SQL query
SELECT arcs, COUNT() AS nbr_of_digraphs FROM (SELECT ID, COUNT() AS arcs FROM weakly_connected AS tmp1 GROUP BY ID) AS tmp2 GROUP BY arcs
For me, the CUDA 9.0 (as well as 9.1) installer failed to install on a fresh Windows 10 system with the 2015 community edition Visual Studio. The problematic items seems to be the “Visual Studio Integration” , which fails to install and somehow blocks all other items from being installed. Fortunately, there is a way around this and you can still use Visual Studio, but you must download the ~1.5GB local install file. We assume that you have already installed Visual Studio Community 2015. Continue reading →
Let us assume that you want to use the famous Programmer’s Dvorak keyboard layout on Windows 10. Unfortunately, this layout is not a stock option. And usually even if there would be a stock option, that option probably would lack ä,ö,ü, and ß as AltGr-choice for a,o,u, and s. Continue reading →
First of all, the Schecter Demon 7 (lefty) guitar is a quite reasonable priced stock guitar that comes with a good value for the buck. Therefore I decided that I could just go with some more radical modifications which I never dared to try before. Continue reading →
Okay, here is a short account of what modifications I did with my new Jackson SLATFXQMG 3-8 TGR. First of all, I installed Schaller Security Locks as a replacement for the strap lock system that comes with the guitar. I did this only for one reason: I have the same locks on all my other guitars and I like to use any strap I own with any guitar I own. Continue reading →
If you are a real fan of the programmer’s Dvorak keyboard layout that is part of X11 on Debian, you might want to use this keyboard layout on a mac, too. Unfortunately, OS X 10.10 (and probably older versions) comes with the standard Dvorak layout only, which can be quite annoying when combined with vim, since the placement of ‘:’ differs. Continue reading →
In this post, I would like to introduce you to a problem posed by Bernhard Ganter on the occasion of the 2014 summer school on “Methodology of task design – How to construct exercises for learning”, as well as some code that I wrote in order to get some exemplary solutions.
The following table was handed to all participants of the summer school:
Today, I want to share a small Python 3 script that I wrote in order to ease the exchange of binary data between Python 3 and C code. For me, sharing data between Python and C is a reoccurring issue, since, usually, I find it more convenient to use Python in order to convert data between different formats and representations. C, on the other hand, usually gives me the raw speed Python cannot offer, but that is needed to do calculations with bigger data sets. Continue reading →