[Octave-bug-tracker] [bug #38628] bsxfun slow for complex

[John Hunt]

URL:
  <http://savannah.gnu.org/bugs/?38628>

                 Summary: bsxfun slow for complex
                 Project: GNU Octave
            Submitted by: huntj
            Submitted on: Fri 29 Mar 2013 07:17:37 PM GMT
                Category: Interpreter
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Performance
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: GNU/Linux

    _______________________________________________________

Details:

bsxfun is slow for complex array. Much slower than broadcasting.
trapz which uses bsxfun is impacted for instance.


octave:1> dx = ones(1, 1, 1000);
octave:2> ym = ones(1, 1, 1000, 1, 201)+i;
octave:3> tic; r = bsxfun(@times, dx, ym); toc
Elapsed time is 1.45173 seconds.
octave:4> tic; r = bsxfun(@times, dx, ym); toc
Elapsed time is 1.46083 seconds.
octave:5> tic; r1 = dx .* ym; toc
warning: product: automatic broadcasting operation applied
Elapsed time is 0.000883102 seconds.
octave:6> assert(r1, r)
octave:7>


these outputs are from dev
hg id -in
a695ee2dc17e+ 16392+

but it holds also for 3.6.3 and 3.6.4





    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?38628>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/