Most likely you have a type problem. Have you tried the various tools: the profiler, Lint, TypeCheck. See http://docs.julialang.org/en/latest/manual/performance-tips/
--Tim On Sunday, September 14, 2014 12:30:29 PM Zac wrote: > Hi I'm trying to port some c++ code to julia for approximating functions on > a sparse grid and have run into a strange 100x slow down that I can't work > out. https://gist.github.com/Zac12345/3da7be1fe99681a5bd14 shows the julia > code and https://github.com/Zac12345/Sparse has the whole module (though > building the shared library can be a faff) > > Though the library uses multi-threading this tends to only give a 6-7x > speedup. > > Is there anything obvious I'm missing out on here? > > ps: profiling shows most of the time is spend (obviously) in the innermost > loop - line 39 of the gist - but a simple comparison of the julia/c++ basis > functions shows the julia version to be considerably faster! > > many thanks
