Matlaby Happiness

Recently, I found myself doing weird things in Matlab (factored MDPs are to blame): using cell arrays, records, and cell arrays of records containing multidimensional arrays… I was already on the verge of using objects. While technically it is possible to do all this, they open unseen depths of code ugliness. Worse than that(??), they make the code really slow: they seem non-Matlabish not only to the human eye, but also to the Matlab interpreter (more on this in a later post).

All of that factored MDP stuff cries for C++ or Java or any normal programming language I don’t speak. I could see two routes: (1) calling Matlab from C++ or C++ from Matlab. I tried both combinations once, and I will not do that ever again. (2) writing everything in C++/Java, which makes the factored MDP parts ten times easier, and everything else (visualization, debugging, statistics) ten times more difficult. So far, I’ve gone for the third route: writing Matlab code with cell arrays of records containing multidimensional arrays, and swearing a lot.

But today I discovered that I can call Java from Matlab, and they mix very smoothly. I don’t know how it will work out in practice, but seems to be quite user-friendly. Automatic type conversion, my word.

I know, Matlab has Java support for ages. Ironically, when Matlab hangs up, it dumps long Java error messages – if nothing else, that could have given me a clue. I could have looked it up in the help, in the documentation, on google. But I have not. Until now. And now I’m happy.

RL-Competition

The Second Annual RL-Competition is over, the results can be seen here. Congratulations to all the winners! The organizers did a great job. They worked an awful lot, and they have been extremely helpful, both on the forums and through email. All in all, I think it has been a great competition.

Still, this post will be about some not-so-well-done details. I’m in an easy position with criticism, because many of the mentioned problems will be eliminated soon or are eliminated already (and because criticism is always easy, anyway. But I’m trying to be constructive, sincerely).

Field report from EWRL, part 2

EWRL is over now, the next part of the is late not only because of the internet access difficulties, but because of extreme exhaustion. Talks from 9am to 6pm, then spontaneous social events with various people, closed by a great banquet (held in a place that functioned as brothel, theater and porn cinema in various stages of its existence, then transformed into a luxurious restaurant). And we’ve got the coolest conference T-shirt ever.

Field report from EWRL, part 1

Well, “part 1″ in the title implies that there will be more, which is quite an optimistic statement considering the hazy state of the wifi network. But apart from that minor point, the conference is absolutely great. I mean, if there are two or three talks on a conference that fit my interests, then it’s already OK for me – and EWRL has much higher hit ratio this far. Here comes my highly subjective selection.