
now I see you, now I don’t
For someone as clumsy as me, it is no real surprise to loose one in three hard disks, but what happened yesterday was a bit puzzling at first. I tried to replace the original 4 Gb hard disk of an original iMac (a tray loading iMac) following the instructions of the MacWorld : how to […]

Singular via GAP on OSX
The GAPpackage is very good in working with finite fields or Abelian extensions of the Rational numbers, but sooner or later we will need to use the coordinate ring or function field of an affine variety for which it is hopeless. On the other hand, there is an excellent free package to do these calculations…

GAP on OS X
GAP the Groups, Algorithms, and Programmingtool (developed by two groups, one in St. Andrews, the other in Aachen) is the package if you want to work with (finite or finitely presented) groups, but it has also some routines for algebras, fields, division algebras, Lie algebras and the like. For years now it is available on…

COLgo
COL is a mapcoloring game invented by Colin Vout. Two players Left (bLack) and Right (white) take turns in coloring the map subject to the rule that no two neighboring regions may be colored the same. The last player to be able to move wins the game. For my talk on combinatorial game theory in…

the iTunes hack
If you are interested in getting thousands of mp3files on your computer using only 128 Kb of ROM, read on! Yesterday I made my hands dirty and with Jan’s help upgraded two 6 Gb colored iMacs (a blue and a pink one) to potential servers for our homenetwork having a 80 Gb resp. a 120…

NOG master class update
Yesterday I made a preliminary program for the first two months of the masterclass noncommutative geometry. It is likely that the program will still undergo changes as at the moment I included only the minicourses given by Bernhard Keller and Markus Reineke but several other people have already agreed to come and give a talk.…

Bill Schelter’s Maxima
Bill Schelter was a remarkable man. First, he was a topclass mathematician. If you allow yourself to be impressed, read his proof of the ArtinProcesi theorem. Bill was also among the first to take noncommutative geometry seriously. Together with Mike Artin he investigated a notion of noncommutative integral extensions and he was the first to…

bandwidth measures
One day (hopefully) lots of MP3, JPEG and perhaps even MPEGfiles will be flying around our wireless homenetwork. But I didn’t have any idea of how much data I could cram through the Airportconnections. To estimate the available bandwith of a network there is a nice free tool around, iperf of which you can download…

google spammers
In the GoogleMatrix I tried to understand the concept of the PageRank algorithm that Google uses to list pages according to their \’importance\’. So, if you want your webpage to come out first in a certain search, you have to increase your PageRankvalue (which normally is a measure of webpages linking to your page) artificially.…

an even better LaTeX system
A previous post the best LaTeX system was a commercial for Gerben Wierda’s iInstaller to get a working tetex distribution. I’ve been working happily with this TeXsystem for two years now but recently run into a few (minor) problems. In the process of solving these problems I created myself a second tetexsystem more or less…