--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/extra/ver20/nansum.m	Wed Oct 10 19:54:49 2001 +0000
@@ -0,0 +1,40 @@
+## Copyright (C) 2001 Paul Kienzle
+##
+## This program 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 program; if not, write to the Free Software
+## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+## v = nansum (X [, dim]);
+## nansum is identical to the sum function except that NaN values are
+## treated as 0 and so ignored.  If all values are NaN, the sum is 
+## returned as 0. [Is this behaviour compatible?]
+##
+## See also: nanmin, nanmax, nanmean, nanmedian
+function v = nansum (X, ...)
+  if nargin < 1
+    usage ("v = nansum (X [, dim])");
+  else
+    dfi = do_fortran_indexing;
+    pzoi = prefer_zero_one_indexing;
+    unwind_protect
+      do_fortran_indexing = 1;
+      prefer_zero_one_indexing = 1;
+
+      X(isnan(X)) = 0;
+      v = sum (X, all_va_args);
+    unwind_protect_cleanup
+      do_fortran_indexing = dfi;
+      prefer_zero_one_indexing = pzoi;
+    end_unwind_protect
+  endif
+endfunction