[Numpy-discussion] insanely slow writing to memory mapped array

[Mathew Yeates]

Hi

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?

Thanks
Mathew