I have been sitting in front of the computer quite a bit in the past few weeks, and I noticed that my eyes get very tired by the end of the day (I used to get back pain too, but stretching helped a lot). After a bit of reading I learned that the maximum-contrast white-on-black-based color scheme I was using is in fact extremely stressful for the eyes, and I started looking for something designed for the specific purpose of reducing eye fatigue. After checking out Zenburn for a few days, I started using Solarized by Ethan Schoonover. I find it really nice and relaxing, here is a screenshot of Emacs editing Common Lisp code:
Tuesday, November 1, 2011
Lately I have been trying to be more organized about updates to my libraries: I always try to keep the master branch on Github in a consistent state for all of them, and merge the development branches for all libraries at the same time. I have been doing that yesterday, here is a brief summary of the changes.
cl-num-utils mostly received minor fixes: I cleaned up the accumulator code a bit, and added a few minor convenience functions. The package now exports
median, which causes a symbol conflict with alexandria:median so you need to shadow if you are using both. Maybe I should ask the developers of Alexandria to make
LLA underwent a medium-scale rewrite: I sanitized the type system (internal types are no longer exposed), cleaned up object creation functions (
CLO replaced with
LOWER, etc), and wrote specialized routines for array sharing which are about 30 times faster than they used to be — this of course doesn't mean that LLA is now 30x faster, just that they overhead for sharing arrays got a lot smaller. Since many operations are \(O(n^\alpha), \alpha \geq 2\), this is mostly noticeable for small arrays. Note that this is still generic CFFI-based code, preliminary tests indicate that implementation-specific tricks could yield array copying code that is 2-5x faster, but currently I have neither the time nor the inclination to write this, because I would rather wait for other parts of LLA to settle down before I micro-optimize. However, if you find that array copying overhead is critical for you, please let me know and I will see what I can do — this rewrite was prompted by the benchmarks sent by Robert Brown.
Realizing that implementing special functions in Common Lisp is perhaps not the best use of my time, I decided to use a foreign library for this purpose in cl-random. I chose R's standalone math library, with an SWIG-generated wrapper (it took about 30 minutes to have this library running, SWIG is amazing). I made the result available as a small standalone library called cl-rmath in case anyone else wants to use it. I really appreciate that the R developers made this available as a standalone library, it makes my life much easier. Besides these changes, I only made small changes to cl-random, for example, the univariate normal now has the syntax
(r-normal mean variance) instead of the standard deviation, to be more consistent with the multivariate case.
Finally, it looks like cl-2d refuses to die, so I fixed some of the minor bugs that were the result of other libraries moving on. I am working on a replacement library, but I will probably keep cl-2d updated until the new library is ready. It amazes me how many people are using cl-2d: I get questions and bug reports all the time. It is not a bad library, but I wrote it when I was a CL newbie and I hope that I can write a much better one — we shall see. In any case, if you are not using cl-2d, I would recommend that you don't start now.