--- /dev/null
+function FLAG = flag_implicit_skip_nan(i)\r
+% FLAG_IMPLICIT_SKIP_NAN sets and gets default mode for handling NaNs
+% 1 skips NaN's (the default mode if no mode is set)
+% 0 NaNs are propagated; input NaN's give NaN's at the output
+% \r
+% FLAG = flag_implicit_skip_nan()\r
+% gets current mode
+%
+% flag_implicit_skip_nan(FLAG)\r % sets mode
+%
+% prevFLAG = flag_implicit_skip_nan(nextFLAG)\r
+% gets previous set FLAG and sets FLAG for the future
+% flag_implicit_skip_nan(prevFLAG)\r
+% resets FLAG to previous mode
+%
+% It is used in:
+% SUMSKIPNAN, MEDIAN, QUANTILES, TRIMEAN
+% and affects many other functions like:
+% CENTER, KURTOSIS, MAD, MEAN, MOMENT, RMS, SEM, SKEWNESS,
+% STATISTIC, STD, VAR, ZSCORE etc.
+%
+% The mode is stored in the global variable FLAG_implicit_skip_nan
+% It is recommended to use flag_implicit_skip_nan(1) as default and
+% flag_implicit_skip_nan(0) should be used for exceptional cases only.
+% This feature might disappear without further notice, so you should really not
+% rely on it.
+
+
+% 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, write to the Free Software
+% Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+% $Id: flag_implicit_skip_nan.m 8351 2011-06-24 17:35:07Z carandraug $
+% Copyright (C) 2001-2003,2009 by Alois Schloegl <alois.schloegl@gmail.com>
+% This function is part of the NaN-toolbox
+% http://pub.ist.ac.at/~schloegl/matlab/NaN/
+
+
+persistent FLAG_implicit_skip_nan;
+
+%% if strcmp(version,'3.6'), FLAG_implicit_skip_nan=(1==1); end; %% hack for the use with Freemat3.6
+
+%%% set DEFAULT value of FLAG
+if isempty(FLAG_implicit_skip_nan),
+ FLAG_implicit_skip_nan = (1==1); %logical(1); % logical.m not available on 2.0.16
+end;
+
+FLAG = FLAG_implicit_skip_nan;
+if nargin>0,
+ FLAG_implicit_skip_nan = (i~=0); %logical(i); %logical.m not available in 2.0.16
+ if (~i)
+ warning('flag_implicit_skipnan(0): You are warned!!! You have turned off skipping NaN in sumskipnan. This is not recommended. Make sure you really know what you do.')
+ end;
+end;
+