Thank you for kind answer. Always I am afraid of unintended copy of buffers because I'm a such a C/C++ guy.
I have read the performance tips when it is early 0.3 version. I surprised that there were lots of updates since then. (julia is developing so fast!) I will try the profiling functions and find unintended allocations. By the way, my another wish is about performance of loading packages. In my code, Image.jl takes ~5 sec for just loading libraries, (new) Interpolation.jl takes even ~20 sec. (maybe cause of metaprogramming codes I think) I heard there will be some package pre-loading or cache feature in v0.4. Is there any updates about that? 2015년 2월 12일 목요일 오전 12시 34분 12초 UTC+9, Tim Holy 님의 말: > > A[:, indx] currently makes a copy. Try replacing it with slice(A, :, indx) > (if > you're on julia 0.4) or use ArrayViews if you're on julia 0.3. > > For performance questions, if you aren't using the tools advertised at > http://docs.julialang.org/en/release-0.3/manual/performance-tips/ > you will likely find them to be a big help. > > --Tim > > On Wednesday, February 11, 2015 07:25:38 AM Kyunghun Kim wrote: > > Hi, all. > > > > I am sorry that I am writing repeating these questions again. > (performance > > compared to ~) > > I have some signal processing code written in MATLAB, and rewriting the > > code with Julia. > > > > The signal processing function take about 1024 x 1024 floating number > array > > as input called in loop about 100~1000 times. > > Here is core function of algorithm: > > > > MATLAB version: https://gist.github.com/moon6pence/3e60772943f206842d31 > > > > >0.16 sec per each call > > > > Julia version: https://gist.github.com/moon6pence/4b43c63cb4240b31ea10 > > > > >1.4 sec per each call > > > > Not only julia code is unusually slow, but MATLAB code is also unusually > > fast. > > (Naive C++ implementation of this code takes 100~200 sec, maybe MATLAB > JIT > > compiler is doing very well in SIMD) > > > > I will dig up this julia code line-by-line to find which line takes much > > time. > > But before then, I want get this code checked if there is any mistake on > > code for performance. (or give me tips for vectorized code) > > > > Thanks. > >
