Neal, I just wrote some fast-ish multirate FIR functions. I seems like you're probable looking for an exercise to learn the language, but if you want a reference you can check them out here <https://github.com/JayKickliter/Radio.jl/blob/master/src/Filter/FIRFilter.jl>. For the interpolating FIR is mostly within 2x of Intel's IPP speed.
On Friday, August 1, 2014 5:33:57 AM UTC-6, Neal Becker wrote: > > Thanks for your help. > > FYI, there are 2 reasons I passed a slice instead of a single element: > > 1. This is just the first of several types of FIR filter. In the case of > an > (efficient) decimating FIR filter, the length of the slice is >1 element > > 2. I want to see how well julia can handle slices > > Sam L wrote: > > > u[i:i] or view(u, i:i) create a one element array/view, so the u in > > shift_and_compute1 and compute1 always has length 1. I changed those > > functions to take a scalar instead of an array and got about a 6 to 9x > > speed up. > > > > Also, you can get rid of most of the type annotations without affecting > the > > performance. The only ones you need are in compute and compute1 > functions, > > because the types are used in those functions. You could alternatively > get > > the types with eltype(f.in) for example and drop those too. > > > > My version is here: https://gist.github.com/lendle/897eea1e5458eedb8e43. > > > > > On Thursday, July 31, 2014 10:10:13 AM UTC-7, Neal Becker wrote: > >> > >> Daniel Jones wrote: > >> > >> > > >> > Here's a version that's 7x faster (and almost 8x if you disable > bounds > >> > checking). The main thing is to avoid indexing into arrays with > ranges > >> (as > >> > in u[i:j]) if you can, since that will allocate and copy a new array > >> each > >> > time. And also, like Patrick said, globals should usually be declared > >> with > >> > 'const'. > >> > > >> > On Thursday, July 31, 2014 8:38:33 AM UTC-7, Neal Becker wrote: > >> >> > >> >> Attached is my 1st attempt at julia, it is a simple FIR filter, > which I > >> >> translated from my c++ version. > >> >> > >> >> It is benchmarking about 10x slower than python wrapped c++ version. > >> >> > >> >> Any suggestions? > >> > >> I was concerned about that indexing arrays causing copying, and to get > >> closer to > >> the c++ version (which does not copy), I tried out ArrayViews. I'll > >> attach that > >> version, but I did not see any speedup. > > >
