Re: accumarray

[etienne]

  Hi David,

On Thu, July 5, 2007 02:57, David Bateman wrote:
# address@hidden wrote:
#>   I would say that correct but slow code is better than no code at all.
#>
#>   Cheers,
#>
#>   Etienne
#>
#>
# Well, I'm back in the office and tried the accumarray in matlab for
# speed and got the following results
#
# vals = 1:1e4;
# subs = randint(1e4,2,1024) + 1;
# t = 0;
# for i=1:10,
#   t0 = cputime();
#   A = accumarray (subs, vals, [1024,1024]);
#   t = t + cputime() - t0;
# end;
# fprintf('Time %g s\n', t / 10);
#
# MatlabR2007a
# Time 0.016 s
#
# Octave 2.9.12
# Time 1.21592 s
#
# So there is a factor of 76 difference in speed for this example. So
# Etienne how useful is this function, and what portion of your simulation
# time will be spent in it?

I usually am first happy when code work correctly; if it is fast too, that's
better, but I place correctness first. I am sure that people who have M* code
w/ accumarray() in it will rather be able to run their code than not.

  Cheers,

  Etienne

# Cheers
# David
#
#
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