Re: Newbie question about vector performance

[Rubén Béjar]

Hi again, I have tried a few more things: I have done the same in Java but using an array of Integers, instead of an array of ints. It just takes 78 ms. (more than 16, still far less than 4 secs). I have also tried with an update function which just returns a fixed 1. It still takes some 400 ms. to update de data vector of the CA. This is similar to the time it is giving me to create a vector of 1's with this function: (time (vec (repeat 250000 1))). I was not expecting Clojure vectors so much slower than Java arrays. Is that comparison so "unfair"? Next thing I am trying is using Java Vectors in my Java implementation...    Rubén Rubén Béjar escribió: Hi all, I am new to the list and to Clojure. I have been working in implementing some 2D cellular automata (CA) just to have a project to teach Clojure to myself. After some work I have something that works, but it is pretty slow. The function that takes a CA of 500x500 cells (integers) and returns an updated (*) copy takes 4 s. (using Clojure vectors), while doing more or less the same in Java (using arrays and primitive types) takes more or less 16 *ms.*. I expected some difference, but not that big. Before trying to use Java arrays and primitive types in Clojure, I would like to know how my Clojure approach can be improved  (I am willing to sacrifice some performance to keep it "more Clojure", but not that much). As I do not want to post a bunch of horrible code full of comments and not properly indented, I have extracted what i hope are the main pieces, written some comments and posted it here: http://snipt.org/Okpk Pasting that code in a new file in Eclipse (I am using counterclockwise) and running it in the REPL prints this: Clojure 1.1.0-alpha-SNAPSHOT "Elapsed time: 4355.363706 msecs" "Elapsed time: 4416.98562 msecs" 1:1 user=> #<Namespace cellular-automata-basic> 1:2 cellular-automata-basic=> I would thank a lot any hint, suggestion, comment, or whatever... :-) Best regards,    Rubén (*) The update consists on adding the values of the 8 neighbours of every cell and changing it if that sum is between two fixed numbers. -- Rubén BÉJAR HERNÁNDEZ Dpto. de Informática e Ingeniería de Sistemas - Universidad de Zaragoza (Computing and Systems Engineering Department - Universidad de Zaragoza) c/ María de Luna 1, 50018 Zaragoza, Spain Tel: (+34) 976 76 2332 (Fax: 1914) e-mail: rbe...@unizar.es Grupo IA3 (IA3 Laboratory) - http://iaaa.cps.unizar.es -- 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