Converting a mutable-array into a vector in Racket (not Typed Racket) seems to be faster when done element-wise instead of using mutable-array-data. Why is this? I always thought crossing the untyped/typed boundary as little as possible makes things run faster.
This little test program #lang racket (require math/array) (define arr (mutable-array #[#[1. 2. 3.] #[4. 5. 6.]])) (define (array->vector1 arr) (for/vector [(a (in-array arr))] a)) (define (array->vector2 arr) (mutable-array-data arr)) (define N 5000) (time (for [(i N)] (array->vector1 arr))) (time (for [(i N)] (array->vector2 arr))) results in racket arr-vec.rkt cpu time: 946 real time: 961 gc time: 58 cpu time: 1270 real time: 1283 gc time: 4 Best, Berthold -- ----------------------------------------------------------------------- Berthold Bäuml -- Head of Autonomous Learning Robots Lab DLR, Robotics and Mechatronics Center (RMC) Münchner Str. 20, D-82234 Wessling Phone +49 8153 282489 http://www.robotic.de/Berthold.Baeuml -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
