[Numpy-discussion] insanely slow writing to memory mapped array
robert.kern at gmail.com
Wed Nov 29 18:51:40 CST 2006
Mathew Yeates wrote:
> I have a line in my program that looks like
> outarr[1,:] = computed_array
> where outarr is a memory mapped file. This takes forever.
> I checked and copying the data using "cp" at the command line takes 1
> or 2 seconds. So the problem can't be attributed simply to disk i/o. Is
> it because the elements are being written one at a time? Any ideas on
> how to speed this up?
Memory-mapping is highly platform dependent. What platform are you on? What are
the sizes of the arrays? Can you write up a small, self-contained script that
demonstrates the issue so we can experiment and try things out on different
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
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