Distributed, not scattered: Blog

Printer woes

by derwischderwisch 28 Nov 2015 06:55: 0 comment(s)

The following lines reflect my attempts to get my new printer to do my bidding.

2048 Racket

by derwischderwisch 11 Oct 2015 11:24: 0 comment(s)

An analysis of Patchwork tiles

by derwischderwisch 19 Jul 2015 03:54: 0 comment(s)

Patchwork is a 2-player game by Uwe Rosenberg which uses known mechanisms (tile-fitting, a time row, a circular card row, economics with multiple resources) and combines them in a refreshing way. Like many 2-player games, it can get confrontational as denying your opponent nice things is as good as getting nice things yourself. There has been some discussion about which tiles are "nice", which ones are adequately priced, and which ones are the real bargains.

Maperitive woes

by derwischderwisch 22 Dec 2012 06:38: 0 comment(s)

No discussion of make(1) would be complete without an acknowledgement that it includes one of the worst design botches in the history of Unix. The use of tab characters as a required leader for command lines associated with a production means that the interpretation of a makefile can change drastically on the bases of invisible whitespace.

Polysleuth: Rules

by derwischderwisch 09 Dec 2012 21:55: 0 comment(s)

Polysleuth is a variation of Sid Sackson's deduction game classic "Sleuth". Players try to infer the distribution of cards between their opponents with help of their own cards and questions. The player who scores the most sleuth points wins. Game can be played with 3 to 7 players.

USB problems on an Ubuntu box

by derwischderwisch 26 Feb 2012 20:03: 0 comment(s)

My Ubuntu box displays very few connected devices automatically. As this Wiki hoster provides some ways to markup I'll use this site to document what I have tried.

Food consumption in different countries

by derwischderwisch 15 Apr 2010 11:53: 0 comment(s)

The New York Times presented a bar chart on food consumption in different countries. Here is a correspondence analysis on the distribution


, and here is the R code needed to produce it:

Digitise graphs with R

by derwischderwisch 06 Mar 2010 06:14: 0 comment(s)

Part of deciding on the size of an experiment is literature search. Has the suggested response variable been used before? (Most possibly.) What rate of an event is to be expected? What distribution does the response have? More often than not, however, especially the last question cannot be reliably answered, as many articles report effect size, p-value, period. If the hapless statistician is lucky, he will see the desired data in a box-and-whiskers plot, a dot chart or a scatter plot. A couple of times I have found myself trying to recover the original data using a ruler.

Das Ehrenamt, oder Türschloss: 0, siebzehn Feuerwehrleute: 1

by derwischderwisch 25 Oct 2009 06:53: 0 comment(s)

Sie sind der Sauerteig, der die Gesellschaft zusammenhält, und der Kitt, der sie treibt. Sie wirken im Verborgenen und erbringen Leistungen, für die man Profis niemals bezahlen wollte. Manchmal treten sie auch an die Öffentlichkeit und lassen den Leser spüren, wofür sie ihre Freizeit opfern. Ihre Plattform ist das örtliche Mitteilungsblatt der Gemeinde. Ein Beispiel soll verdeutlichen, wohin das führen kann.

Finding coarse highways in Openstreetmap

by derwischderwisch 30 Dec 2008 20:40: 0 comment(s)

Openstreetmap is a rich project with diverse users and entries. As such, the data base is rife with insufficient, contradictory or plain ugly entries. Some people would like not to have any entry there rather than one that might be an embarrassment. Others applaud the fact that there is an entry at all, and wait for crowd wisdom to set things straight. And there are others who build tools such as the OSM inspector that hint at possible problems so that helpful gnomes may take care of them.

Map of Openstreetmap authors in Germany

by derwischderwisch 16 Nov 2008 21:58: 0 comment(s)

I am just getting to know the Openstreetmap data and playing around with the most basic elements and attributes. Using the user and coordinate data of all nodes, I set up a graphic that divides Germany into 100 km^2 squares, counts the number of nodes and colours the dots (of size dependent on the number of nodes found here) according to the number of users that contributed at least 50 per cent to the nodes in this square. When you load the SVG you may be able to read the user contributing most in that area by mouseover.

List of rectified maps

by derwischderwisch 28 Sep 2008 07:08: 0 comment(s)

Recently I have discovered Openstreetmap. As I have always loved maps, and have appreciated the approach to free software for so long, I figured this is just the project for me. I am really hooked. Yes, my bicycle tour is still described with Google Maps, but this will change one I have worked out how to embed maps with routes (and until all ways have been mapped; after all, I want to switch to improve).

PocketMod and pstops

by derwischderwisch 10 May 2008 08:04: 0 comment(s)

The joys of Unix are the versatile tools available. The downside of many of these tools is their usability. A role model for this general observation is pstops. It allows to rearrange Postscript pages according to any order and rotation you like (well, ok, rotation by 90° steps), mostly in order to prepare documents for printing, such as brochures. The versatility comes at a cost, though. First, the notation is a bit terse. I won't go into the details, you can have a look at the man page to see what I mean. Second, adjusting the rotation and shifting requires some geometric thinking. As the rotation is around a corner and happens prior to translation, pages are rotated "out of sight" if not translated, and people lacking discipline in geometric thinking (such as me) are bound to applying trial and error.

43rd birthday tour

by derwischderwisch 24 Mar 2008 19:52: 0 comment(s)

On Easter Monday was my birthday (probably the only time in my lifetime).


by derwischderwisch 15 Dec 2007 20:27: 0 comment(s)

Früher, als der Intercity noch das Flaggschiff der Bahn war, wurde seine Benutzung mit einem entfernungsunabhängigen Zuschlag belegt. Die Reise mit Fernzügen unterhalb der IC-Gattung war zuschlagfrei. Es gab auch zuschlagfreie Intercitys. Diese hatten häufig Orte wie Munster (Örtze) als Ziel und waren im Kursbuch Schiene mit dem Vermerk "Besonders geeignet für Bundeswehr-Familienheimfahrten" versehen. Diese Formulierung wurde unter anderem von Max Goldt angemessen gewürdigt. Heißt sie doch eigentlich "Besonders ungeeignet für Fahrgäste, die ungern in Gesellschaft von Betrunkenen reisen".

Apple treats own messages as spam

by derwischderwisch 31 Oct 2007 05:13: 0 comment(s)

This morning I checked my mail. Only two new messages, on of them marked as spam. Upon a second look, this mail was sent by an Apple e-mail address. The mail program shipped by Apple categorized this message from the vendor's domain as spam. Note that I did not go out of my way before to train the filter very much. It seems that the spam filter does not use a whitelist for Apple's own domain. This contributes somehow to the reputation that Apple is more on the side of the consumers, while Microsoft, if pressed, tends to lean to big corporations. Not that I buy into this image, but this behaviour definitely supports it.

Sealing the Seams

by derwischderwisch 11 Aug 2007 13:31: 0 comment(s)

Shaky weather nonwithstanding, we are still planning for a camping vacation. Last time we pitched our tent I found that it starts to show its age. It is a WeatherMaster plus by Coleman purchased in 2002. We have used it since then for a total of maybe seven weeks, during one- or two-week holidays, the two-week periods spent in the Netherlands near the coast. The tent withstood some wind and rain with bravado, overall we're quite happy with it.


The last time we've been using it (a couple of weeks ago), I noticed that the textile tapes which seal the seams between floor and walls from the inside are going off at several places.


It seems that the glue is losing its function. Therefore, I went down to the local outdoor store where they recommended me a tube of seam sealer by Edelmann & Ridder, Isny (it rains a lot down there, so they should know their job). The dealer said that this sealer works on 70 per cent of the tent fabrics being sold, so good luck to me.

Misconceptions about SAS: The MERGE statement

by derwischderwisch 07 Aug 2007 16:45: 0 comment(s)

Recently, I used the MERGE statement to attach information about treatment group to the patient data. The patient data have more than one observation (or, to the non-SAS crowd out there, record) per patient while the additional information is patient-specific and therefore has only one observation per patient. Treatment was coded as 0=Placebo and 1=Verum. For the sake of clarity, let's assume the tables were set up like this:

Forest plots

by derwischderwisch 07 Aug 2007 16:36: 0 comment(s)

A couple of weeks ago I sat in a SAS course to refresh my memory about graphics in SAS. Near the end of the talk the question was posed if SAS could do forest plots. The speaker, not knowing the term, asked for an explanation.

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