On Mon, Oct 31, 2016 at 6:34 PM, Ian Butterworth <i.r.butterwo...@gmail.com> wrote: > I'm not sure of the etiquette, but I'm cross-posting this from stackoverflow > as it seems like quite a significant issue... > > As an example: > > x = rand(10,10,100,4,4,1000) #Dummy array > > tic() > r = squeeze(mean(x[:,:,1:80,:,:,56:800],(1,2,3,4,5)),(1,2,3,4,5)) > toc() > > Julia 0.5.0 -> elapsed time: 176.357068283 seconds > > Julia 0.4.7 -> elapsed time: 1.19991952 seconds > > > > I know this isn't really good practice, and I'm looking into using `view` > but it's quite a bit performance decrease, so I thought I'd raise it. >
AFAICT it's all compilation time. > > http://stackoverflow.com/questions/40351485/why-is-indexing-a-large-matrix-170x-slower-slower-in-julia-0-5-0-than-0-4-7
