# HG changeset patch
# User Jaroslav Hajek <highegg@gmail.com>
# Date 1232518032 -3600
# Node ID 1cb63ac13934e508fced41fffea517cf2aa04783
# Parent  424ba638d8f1e5bdd45162af002689eaba2f3343
allow fsolve work without qrupdate

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,7 @@
+2009-01-20  Jaroslav Hajek  <highegg@gmail.com>
+
+	* optimization/fsolve.m: Only use qrupdate if available.
+
 2009-01-20  John W. Eaton  <jwe@octave.org>
 
 	* general/postpad.m: Doc fix.
diff --git a/scripts/optimization/fsolve.m b/scripts/optimization/fsolve.m
--- a/scripts/optimization/fsolve.m
+++ b/scripts/optimization/fsolve.m
@@ -67,6 +67,8 @@
 
 function [x, fvec, info, output, fjac] = fsolve (fcn, x0, options)
 
+  persistent have_qrupdate = exist ('qrupdate') == 5;
+
   if (nargin < 3)
     options = struct ();
   endif
@@ -266,7 +268,11 @@
       endif
 
       ## Update the QR factorization.
-      [q, r] = qrupdate (q, r, u, v);
+      if (have_qrupdate)
+        [q, r] = qrupdate (q, r, u, v);
+      else
+        [q, r] = qr (q*r + u*v');
+      endif
 
     endwhile
   endwhile