Tuesday, August 19, 2008


Assuming we've got a long random string composed of the letters H and T, and only those two letters, which of the patterns "HTH" or "HTT" (overlap not allowed) do you think will occur more frequently?

For example, if overlap is not allowed, in the string "HTHTHTTH", both "HTH" and "HTT" occur once. However, if we allow for overlap, then "HTH" occurs twice and "HTT" once.

So, the question is, which of the patterns "HTH" or "HTT" (without overlap) do you think will occur more frequently? Will "HTH" occur at a higher, the same or lower frequency than "HTT".

You must give an answer.

To find out the answer run the Simulation application written in Java.

This question is an adaptation of the question asked by Peter Donnelly in his TED presentation on "How juries are fooled by statistics."

Friday, August 01, 2008

Subversion+Eclipse on Linux

I usually develop on Windows on a fairly fast PC. However, our continuous integration server runs on Linux. For some reason, some tests were failing intermittently on the integration server. Now, since the integration server was heavily used by other processes and the tests in question were time-sensitive, the next step was to fix whatever bug there was by developing on the integration server. This just shortens the patch+test cycle.

Installing Eclipse Ganymede on this Linux machine was a breeze. Everything just worked out of the box. Well, not everything. SVN integration was missing. Installing Subclipse did not work nor did Subversive, at least not until I stumbled upon Basilikk's blog entry on Eclipse 3.4 Ganymede and Subclipse 1.4.

The critical paragraph was:
The second alternative is to also install the SVNKit adapter. This immediately causes Subclipse to work, there is no need to uninstall the JavaHL adapter. Downside of this of course is that you are using a beta version of the adapter. Hopefully there will be a final version of this adapter and an update to Subclipse 1.4.x to include a stable SVNKit soon.

In short, selecting the "SVNKit Adapter" during the usual installation of Subclipse worked as a charm.