--- /dev/null
+## Copyright (C) 2001 Paul Kienzle <pkienzle@users.sf.net>
+##
+## 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 3 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, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {[@var{v}, @var{idx}] =} nanmax (@var{X})
+## @deftypefnx{Function File} {[@var{v}, @var{idx}] =} nanmax (@var{X}, @var{Y})
+## Find the maximal element while ignoring NaN values.
+##
+## @code{nanmax} is identical to the @code{max} function except that NaN values
+## are ignored. If all values in a column are NaN, the maximum is
+## returned as NaN rather than [].
+##
+## @seealso{max, nansum, nanmin, nanmean, nanmedian}
+## @end deftypefn
+
+function [v, idx] = nanmax (X, Y, DIM)
+ if nargin < 1 || nargin > 3
+ print_usage;
+ elseif nargin == 1 || (nargin == 2 && isempty(Y))
+ nanvals = isnan(X);
+ X(nanvals) = -Inf;
+ v = max (X);
+ v(all(nanvals)) = NaN;
+ elseif (nargin == 3 && isempty(Y))
+ nanvals = isnan(X);
+ X(nanvals) = -Inf;
+ v = max (X,[],DIM);
+ v(all(nanvals,DIM)) = NaN;
+ else
+ Xnan = isnan(X);
+ Ynan = isnan(Y);
+ X(Xnan) = -Inf;
+ Y(Ynan) = -Inf;
+ if (nargin == 3)
+ v = max(X,Y,DIM);
+ else
+ v = max(X,Y);
+ endif
+ v(Xnan & Ynan) = NaN;
+ endif
+endfunction