# HG changeset patch
# User jwe
# Date 876500808 0
# Node ID b06dcbb6b3b106fc70b2607e9103b77c3de3c35b
# Parent  63bda47c6512e1164a4d23a360a4be8975b03da5
[project @ 1997-10-10 16:26:47 by jwe]

diff --git a/scripts/ChangeLog b/scripts/ChangeLog
--- a/scripts/ChangeLog
+++ b/scripts/ChangeLog
@@ -1,3 +1,9 @@
+Fri Oct 10 11:18:10 1997  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* polynomial/polyfit.m: Compute yf correctly.  From Seung Lee
+	<SJL@nrc.gov>.  Also return yf in the same orientation as the
+	original y vector.
+
 Fri Sep 19 17:04:40 1997  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
 	* linear-algebra/cross.m: Use direct formula instead of calling
diff --git a/scripts/polynomial/polyfit.m b/scripts/polynomial/polyfit.m
--- a/scripts/polynomial/polyfit.m
+++ b/scripts/polynomial/polyfit.m
@@ -1,4 +1,4 @@
-## Copyright (C) 1996, 1997 John W. Eaton
+## Copyright (C) 1996 John W. Eaton
 ##
 ## This file is part of Octave.
 ##
@@ -45,6 +45,8 @@
     error ("polyfit: n must be a nonnegative integer");
   endif
 
+  y_is_row_vector = (rows (y) == 1);
+
   l = length (x);
   x = reshape (x, l, 1);
   y = reshape (y, l, 1);
@@ -61,14 +63,20 @@
 
   X = (x * ones (1, n+1)) .^ (ones (l, 1) * (0 : n));
 
-  p = flipud ((X' * X) \ (X' * y));
+  p = (X' * X) \ (X' * y);
+
+  if (nargout == 2)
+    yf = X * p;
+  endif
+
+  p = flipud (p);
 
   if (! prefer_column_vectors)
     p = p';
   endif
 
-  if (nargout == 2)
-    yf = X * p;
+  if (y_is_row_vector)
+    yf = yf';
   endif
 
 endfunction