Pie Day!

and keeping with the mathematics, here’s an octave version of conway’s game of life! thanks sasha! happy birthday!

axis([0 N+1 0 N+1], "manual","square", "nolabel");
H=diag(ones(1, N-1), 1) + diag(ones(1, N-1), -1) + eye(N);
for i =1:1000;
 An = H*A*H-A;
 A(find(An<2 | An>3)) = 0;
 A(find(An==3)) = 1;

 [x, y] = find(A);
 plot(x, y, 'o;;');

that should answer benno’s question.

Happy Pie Day!

codefest, project overload

At K’s codefest yesterday I spent most of the time reading some papers on using linear algebra to approximate spring embedders for three dimensional graph layout. Lots of pretty pictures in graph drawing papers, alas the eigenvectors melted my brain. Today I tried to find the old uni linear algebra textbook but it eluded me.

Instead I hacked on a chroot builder for Red Hat 8.0 and 9 that I’d started on Friday – I didn’t work on it yesterday at the codefest due to the interesting quirk that Red Hat’s i386 packages don’t really like installing on a powerpc architecture, which I suppose could have been solved with the –ignorearch option but I didn’t bother to delve. Anyway, back at home the trusty workstation built minimal Red Hat roots many times during the day. This is just stage one in my master plan.

It sucks to have three or four projects to be working on at once: I find I never do any of them… or they block on a hard problem and end up stagnating as I procrastinate and do something else. Needless to say the garden is looking cleaner and the dishes get washed regularly.

databases, elisp, vim major mode

Well, last week sucked a lot. An upside of being overworked is that I know more about database performance tuning and OS scheduling than I did before, and honed some profiling skills. All this whilst working hard and fast in a low morale environment! I must be made of steel or something.

Anyway, I’ve now got some more emacs major modes: in addition to zonefile.el, there’s graphviz.el for syntax highlighting of graphviz style dot files and filtergen.el for highlighting the filtergen rules syntax. These, again, are in my elisp--main--0 arch repository.

James had a good idea last week: a major mode that reads the vim syntax files, thus giving emacs users access to all the exsiting vim highlighting. So evil it just might work.


The other day I was adding some entries to our DNS, using the power of emacs tramp, and it occurred to me that the zone file wasn’t syntax highlighted like vim does it, and unlike when using the wrapper scripts Eman wrote, I had to manually increment the serial number and reload the nameserver. That’s so much effort.

So just now I whipped up a zonefile.el that so far does the syntax highlighting, but it’s a good start. It’s in my arch repo under the imaginatively titled branch elisp--main--0.