On Thu, Nov 4, 2010 at 5:43 PM, Mike Meyer <mwm-keyword-googlegroups.620...@mired.org> wrote: > On Thu, 4 Nov 2010 22:28:12 +0100 > Pepijn de Vos <pepijnde...@gmail.com> wrote: > >> Hi all, >> >> I have written a Python script to analyze Minecraft levels and render a >> graph. Then I did the same with Clojure. It takes Python 10 seconds to >> analyze a map, while it takes Clojure over a minute. >> >> After having tried different options without any significant improvement, I >> am lost as to why there is such a huge difference. I wouldn't mind an extra >> pair of eyes/brains to look at this. >> >> I blogged about it in more detail here: >> http://pepijndevos.nl/clojure-versus-python >> Clojure version: https://github.com/pepijndevos/Clomian/ >> Python version: https://github.com/l0b0/mian >> >> Clojure spends most of its time in the freqs function, here are a couple of >> variations: https://gist.github.com/663096 >> >> If you want to run the code yourself, you'll need a Minecraft level and >> JNBT, which is not on Maven. >> JNBT: http://jnbt.sourceforge.net/ >> The level used in the blogpost: http://dl.dropbox.com/u/10094764/World2.zip > > Can you check GC activity in the clojure version? > > I once ran into an issue where Python was running rings around an > Eiffel version (compiled down to native code - no VM need apply). This > looks similar to what you have, in that I built a large data > structure, and then started groveling over it. Turned out that Eiffel > was doing a mark-and-sweep GC, which was spending all of it's time > marking and sweeping the large static data structure, whereas python > doing a reference count GC didn't. Given that I know nothing about > Java GCs, this is just a WAG. > > Come to think of it, how about trying to run the program Jython? That > should have the same GC issues. If it's some similar environmental > problem, that would show up there as well.
There are many different collectors for the JVMs, too numerous to list here, all tunable. http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html -- http://www.apgwoz.com -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
