Diff of /inst/benchmark_stmm.m [000000] .. [035a3e] Maximize Restore

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+% Copyright (C) 2008  Jaroslav Hajek <highegg@gmail.com>
+% 
+% This file is part of OctaveForge.
+% 
+% OctaveForge is free software; you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation; either version 2 of the License, or
+% (at your option) any later version.
+% 
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+% 
+% You should have received a copy of the GNU General Public License
+% along with this software; see the file COPYING.  If not, see
+% <http://www.gnu.org/licenses/>.
+% 
+
+% function benchmark_stmm (n, nvec)
+% description:
+% Sparse transposed matrix-vector multiplication benchmark.
+% This is to test the "compound operators" feature introduced in Octave.
+%
+% arguments:
+% n = dimension of matrix
+% nvec = number of vector op repeats
+%
+% results:
+% time_tmm = Time for A'*B (B n^2-by-nvec matrix)
+% time_tmv = Time for A'*v nvec-times (v vector)
+% time_mtm = Time for B*A' (B nvec-by-n^2 matrix)
+% time_mtv = Time for v*A' nvec-times (v vector)
+%
+
+function results = benchmark_stmm (n, nvec)
+
+  benchutil_default_arg ('n', 300);
+  benchutil_default_arg ('nvec', 100);
+
+  benchutil_initialize (mfilename)
+
+  disp ('constructing sparse matrix')
+  n = 300; % size of the grid
+  m = n^2; % number of points
+  X = (n-1)*rand (m, 1); Y = (n-1)*rand (m, 1);
+  IX = ceil (X); JY = ceil (Y);
+  
+  A = sparse(m, n^2);
+  A = A + sparse (1:m, sub2ind ([n, n], IX  , JY  ), (IX+1-X).*(JY+1-Y), m, n^2);
+  A = A + sparse (1:m, sub2ind ([n, n], IX+1, JY  ), (X - IX).*(JY+1-Y), m, n^2);
+  A = A + sparse (1:m, sub2ind ([n, n], IX  , JY+1), (IX+1-X).*(Y - JY), m, n^2);
+  A = A + sparse (1:m, sub2ind ([n, n], IX+1, JY+1), (X - IX).*(Y - JY), m, n^2);
+  
+  v = ones (m, nvec);
+  tic; u = A'*v; time_tmm = toc;
+  benchutil_set_result ('time_tmm')
+  
+  v = ones (m, 1);
+  tic; 
+  for i=1:nvec
+    u = A'*v; 
+  end
+  time_tmv = toc;
+  benchutil_set_result ('time_tmv')
+  
+  v = ones (nvec, m);
+  tic; u = v*A'; time_mtm = toc;
+  benchutil_set_result ('time_mtm')
+  
+  v = ones (1, m);
+  tic; 
+  for i=1:nvec
+    u = v*A'; 
+  end
+  time_mtv = toc;
+  benchutil_set_result ('time_mtv')
+