debian

ARPACK situation

Jordi

An open letter to all ARPACK users and developers

I’m writing this email to discuss the future of ARPACK. The problem is this: it’s a widely-used library, but it seems abandoned upstream (and upstream, to whom this is addressed, can confirm or deny). This has resulted in the problem of many mini-forks as each organisation distributes ARPACK patches its own way, and very often, for the same bugs. These are the ones I could find:

Additionally, the Mathworks (they make Matlab) probably also has their own version of ARPACK, but I wasn’t able to find a public version of it, nor an email to send them questions to. If someone could contact them, it would be nice to let them know.

These all seem to have modified ARPACK in some way, with minor or major bugfixes, and as far as I can tell, have mostly done so independently. To me, this seems like unnecessary work, if we’re all patching the library again and again and making our own private forks. What I therefore propose is to have some sort of central location for it and we all pool our efforts on this one location. I think it would be easiest to use Andreas Klöckner’s existing fork on github, since this requires the least maintenance and work from anyone. All that it requires for now is for each of the people above to see what patches they have made and transplant them to the git repo.

It would be helpful if upstream could confirm that they are happy with ARPACK development continuing on github and mention this on the ARPACK webpage, so that new people who are interested on ARPACK can be redirected.

Thanks,
– Jordi G. H.
GNU Octave developer

Knitting for geeks

Jordi

Margarita Manterola from Debian Women asks:

So, after the whole Wikip. thing, I ended up following lots of links
about knitting, and as everytime I come in contact with this, I feel
like I should learn to knit (or maybe I should say, re-learn, I was
taught during primary school, but forgot all about it afterwards).

Is there a “knitting for geeks” tutorial around? :)

There’s tons of videos in YouTube to get you started, although I don’t think many of them are “for geeks” specifically… or at least different kind of geeks. Knitters geek out over types of yarn, needles, complicated patterns, unorthodox knitting, knaughty knitting (e.g. knitting a bra or a thong)… they do end up speaking a special kind of language and getting very passionate about it. What worked for me was when my mom sat down with me to teach me how to cast on, the basic knit and purl stitch, and from then on I was able to bootstrap my first scarf. Perhaps you can learn from videos instead. We didn’t have YouTube when I learned how to knit, heh.

I personally do appreciate a certain mathematical aspect of knitting. I got started because I saw a friend in algebra class in university (y’know, the Galois theory kind of algebra) do complicated lace patterns with needles while she was listening to the lecture, so I was intrigued (and later in love, long story). My kind of mathematical knitting is usually limited to things like knitting a Möbius scarf (non-orientable knitting!) or a hyperbolic plane (negative curvature knitting!). It’s rather remarkable how with just a few basic stitches you can build very complicated things. It does feel a little like Turing machines!

If you need a book, I rather like the Vogue knitting series myself. I hear Stitch’n’Bitch is popular. And most knitting magazines also have introductory instructions in every issue. I liked Knit 1, another Vogue publication, or you can read Knitty online. Knit 1 seems to have ceased publication, but you can probably find back issues in your LYS[1].You might also want to find people near you to knit with, in which case language can be a slight hurdle at first. I really enjoy social knitting. I actually get a little lonely when I can’t find people to share my knitting with.

Incidentally, it’s kinda interesting how knitting patterns are a lot like source code, with similar kind of politics. People share them, remix them, some jealously guard them and try to sell them, others want to ensure as many people as possible can compile your knitting instructions… Interesting world, definite parallels with the free software world.

[1] Local yarn store… too bad most knitting distros don’t ship with the wtf(1) binary. ;-)