# HG changeset patch
# User Jordi Gutiérrez Hermoso <jordigh@octave.org>
# Date 1320447327 14400
# Node ID 94a37dae80a94b0f5f26234c11a4e60b7e48bed2
# Parent  38e3bfc4e076c24c481ac383c2d7e09fc40cacef
Use a cheaper Cholesky decomposition than a rank() svd in ols.m

diff -r 38e3bfc4e076 -r 94a37dae80a9 scripts/statistics/base/ols.m
--- a/scripts/statistics/base/ols.m	Fri Nov 04 16:40:07 2011 -0400
+++ b/scripts/statistics/base/ols.m	Fri Nov 04 18:55:27 2011 -0400
@@ -109,12 +109,12 @@
 
   ## Start of algorithm
   z = x' * x;
-  rnk = rank (z);
+  [u, p] = chol (z);
 
-  if (rnk == nc)
-    beta = inv (z) * x' * y;
+  if (p)
+    beta = pinv (x) * y;
   else
-    beta = pinv (x) * y;
+    beta = u \ (u' \ x' * y);
   endif
 
   if (isargout (2) || isargout (3))