Interesting read Jose, thanks! It might be interesting to try a transducer on
(defn dot-prod "Returns the dot product of two vectors" [v1 v2] (reduce + (map * v1 v2))) if you can get your hands on the 1.7 alpha and the time and inclination to do it. Transducers have shown to be faster than running functions in sequence. Although I don't know how likely they are to beat native arrays, probably not very much. On Sunday, December 21, 2014 7:10:41 PM UTC+1, Jose M. Perez Sanchez wrote: > > > Regarding the speed optimizations, execution time for a given model was > reduced from 2735 seconds to 70 seconds, over several versions by doing > several optimizations. > > The same calculation implemented in C# takes 12 seconds using the same > computer and OS. Maybe the Clojure code can still be improved, but for the > time being I'm happy with the Clojure version being six times slower, since > the new software has many advantages. > > For these tests the model was the circle with radius 1 using the "diffmr1" > tracker, the simulation was run using 10000 particles and 10000 total > random walk steps. > > These modifications in the critical parts of the code accounted for most > of the improvement: > > - Avoid reflection by using type hints. > - Use Java arrays. > - In some cases call Java arithmetic functions directly instead of Clojure > ones. > - Avoid using partial functions in the critical parts of the code. > > Avoiding lazyness did not help much. Regarding the use of Java arrays, > there are many small functions performing typical vector operations on > arrays, such as the following example: > > Using Clojure types: > > (defn dot-prod > "Returns the dot product of two vectors" > [v1 v2] > (reduce + (map * v1 v2))) > > Using Java arrays: > > (defn dot-prod-j > "Returns the dot product of two arrays of doubles" > [^doubles v1 ^doubles v2] > (areduce v1 i ret 0.0 > (+ ret (* (aget v1 i) > (aget v2 i))))) > > > This gives a general idea of which optimizations helped the most. These > changes are not in the public repository, since previous commits have been > omitted because the code code was not ready for publication (different > license disclaimer, contained email addresses, etc.). If anyone is > interested in the diffs and the execution times over several optimizations, > please contact me. > > Kind regards, > > Jose. > > > On Sunday, December 21, 2014 3:38:35 AM UTC-5, Jose M. Perez Sanchez wrote: >> >> >> Hi everyone: >> >> Sorry that it has taken so long. I've just released the software in >> GitHub under the EPL. It can be found at: >> >> https://github.com/iosephus/gema >> >> >> Kind regards, >> >> Jose. >> >> -- 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
