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changeset 16722:c8bbab6b9e7a

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Avoid converting sparse matrix to full format in svds. * script/sparse/svds.m: fix a bug where the matrix passed as sparse in input would be unnecessarily converted to full storage for computing the maximum magnitude of its nonzeros.
author Carlo de Falco <cdf@users.sourceforge.net>
date Wed, 05 Jun 2013 13:49:47 +0200
parents a71a784c7611
children 45b57ac44854
files scripts/sparse/svds.m
diffstat 1 files changed, 5 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/scripts/sparse/svds.m
+++ b/scripts/sparse/svds.m
@@ -137,7 +137,11 @@
   endif
 
   [m, n] = size (A);
-  max_a = max (abs (A(:)));
+  max_a = max (abs (nonzeros (A)));
+  if (isempty (max_a))
+    max_a = 0;
+  endif
+
   if (max_a == 0)
     s = zeros (k, 1);  # special case of zero matrix
   else