On Sunday, October 7, 2012 11:15:28 PM UTC+2, Marc Dzaebel wrote: > > *apply *is slow. However you can increase performance by 60% with the > following macro, if you have a fixed length in S.
> [...] > > (let[t(fn[](*apply *+ '(1 2 3 4 5 6 7 8 9 10)))] (time(dotimes [_ > 1000000] (t)))) ; ~680 msec > (let[t(fn[](*applyn *10 + '(1 2 3 4 5 6 7 8 9 10)))] (time(dotimes [_ > 1000000] (t)))) ; ~220 msec > Interesting, even though it's impractical to use it on an already defined list. Usually, I want to work with list or sequences I've generated with other functions, like so: (let[t(fn[](applyn 10 + (range 1 11)))] (time(dotimes [_ 1000000] (t)))) ; ~ 950 msec (let[t(fn[](applyn + (range 1 11)))] (time(dotimes [_ 1000000] (t)))) ; ~ 940 msec (In addition, apply is in this case is not really what you want to do with this list - you should use reduce instead.) (let[t(fn[](reduce + (range 1 11)))] (time(dotimes [_ 1000000] (t)))) ; ~ 890 msec Curiously, if I vec the result, I get a completely different answer: (let[t(fn[](applyn 10 + (vec (range 1 11))))] (time(dotimes [_ 1000000] (t)))) ; ~ 1330 msec (let[t(fn[](apply + (vec (range 1 11))))] (time(dotimes [_ 1000000] (t)))) ; ~ 1410 msec (let[t(fn[](reduce + (vec (range 1 11))))] (time(dotimes [_ 1000000] (t)))) ; ~ 1340 msec This is hardly any scientific test though, so I'll leave the conclusion to someone with a more rigorous testing scheme. -- 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
