Do you need to use an array? That sounds better suited for a range.
On Tuesday, September 13, 2016 at 10:24:15 AM UTC-7, Neal Becker wrote: > > Steven G. Johnson wrote: > > > > > > > > > On Monday, September 12, 2016 at 7:32:48 AM UTC-4, Neal Becker wrote: > >> > >> PnSeq.jl calls rand() to get a Int64, caching the result and then > >> providing > >> N bits at a time to fill an Array. It's supposed to be a fast way to > get > >> an > >> Array of small-width random integers. > >> > > > > rand(T, n) already does this for small integer types T. (In fact, it > > generates 128 random bits at a time.) See base/random.jl > > > < > https://github.com/JuliaLang/julia/blob/d0e7684dd0ce867e1add2b88bb91f1c4574100e0/base/random.jl#L507-L515> > > > > for how it does it. > > > > In a quick test, rand(UInt16, 10^6) was more than 6x faster than > > pnseq(16)(10^6, UInt16). > > Thanks for the ideas. Here, though, the generated values need to be > Uniform([0...2^N]), where N could be any number. For example [0...2^3]. > So the output array itself would be Array{Int64} for example, but the > values > in the array are [0 ... 7]. Do you know a better way to do this? > > > > > (In a performance-critical situation where you are calling this lots of > > times to generate random arrays, I would pre-allocate the array A and > call > > rand!(A) instead to fill it with random numbers in-place.) > > >
