Octave vs Scilab

[John W. Eaton]

On  6-Oct-2010, Fotios Kasolis wrote:

| So I did not manage to reproduce the example which was like 3 times faster 
| but here is another example (not that bad)
| 
| Windows 7 with binaries Octave 3.2.4 and Scilab 5.2.2 on intel i7 720
| 
| octave.exe:1> xmpl
| 32.430
| 
| ->exec('C:\Users\fotios\Desktop\xmpl.sce', -1)
| 22.411
| 
| where xmpl contains the very intelligent code shown below
| N = 2000
| A = zeros(N,N);
| tic();
| for i = 1:N
|   for j = 1:N
|     A(i,j) = i^2 + j^2;
|   end
| end
| time = toc();
| disp(time)

On my system with the most recent Octave snapshot (3.3.52) I see
31.422 seconds for Octave and 32.9 seconds for Scilab.  And for the
more intelligent

  tic ();
  N = 2000;
  tmp = (1:N).^2;
  A = repmat (tmp, N, 1) + repmat (tmp', 1, N);
  toc ();

I get about .2 seconds for Octave and and error about repmat being
undefined in Scilab.  Using kron instead:

  tic ();
  N = 2000;
  t1 = (1:N).^2;
  t2 = ones (N, 1);
  A = kron (t1, t2) + repmat (t1'; t2');
  toc ();

I get approximately the same results from Octave and

                                                            !--error 17 
: stack size exceeded (Use stacksize function to increase it).

from Scilab the first time I tried it, then it crashed with a segfault
on the second attempt (not that I thought the stack size problem would
go away, I just wanted to see what would happen).

jwe