Closed for Summer (2016)

April 26, 2016

It’s that time again. The semester’s almost over, only a few assignments and exams to mark; everybody’s busy at their own stuff. Like the last few summers, I’ll kind of close the blog until September. I said “kind of” because maybe I’ll post a few things anyway. Especially that this summer will be interesting: more time for research, 7ECM, which I will attend, and a few other things. Seeya in September!

(RGB II, 2560×1440)

(RGB II, 2560×1440)


April 19, 2016

The two seemingly trivial and unimportant problems of what kind of whitespaces and how to use them are still not solved. Some still use hard-coded tabs in their source code, and because they set tabs to be two spaces wide in their favorite editor, they expect the rest of the planet to have done so. The result is that spacing will break in another person’s editor, and the code will look like it’s been written by a four years old. Also, when tabs and spaces are mixed, and randomly interpreted, the indentation, the general aspect of how the code is presented, is broken.


While marking assignments, I encountered a number of such pieces of code. So I decided to fix that with a simple Emacs command.

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Le café des sciences

April 12, 2016

This week, as you might have guessed, was pretty busy as the semester is coming to a close. Among many things, I prepared lecture notes, marked assignments, and all that, but I also got to launch the café des sciences de l’UQAR.


A university is a place where we are supposed to transmit knowledge, but more importantly transmit a love of knowledge and keep alive the joy of discovery. The café des sciences is about that transmission: once a month a guest comes to talk about what his point of view on science is, what research he (or she) is conducting, and everybody is invited. Not only professors. Not only students. Everyone. That’s why the café des sciences will not always be held within the university walls, but will visit café in the general Rimouski area.

You can read more about the café des sciences here. You’re all invited!

You can follow us on twitter at

Making a good random table

April 5, 2016

I am still experimenting with hash functions, and I was toying with the Zobrist hash function[1] that is best known for its use in chess engines. The hash function is conceptually simple: you need a large table of random numbers, indexed, in a chess application, by the position on the board of the piece and by the piece itself. To compute a hash for a whole board configuration, you simply xor all the random numbers together. The hard part is choosing the random numbers.


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