1function FLAG = flag_implicit_skip_nan(i)
2% FLAG_IMPLICIT_SKIP_NAN sets and gets default mode for handling NaNs
3%       1 skips NaN's (the default mode if no mode is set)
4%   0 NaNs are propagated; input NaN's give NaN's at the output
5%
6% FLAG = flag_implicit_skip_nan()
7%   gets current mode
8%
9% flag_implicit_skip_nan(FLAG)    % sets mode
10%
11% prevFLAG = flag_implicit_skip_nan(nextFLAG)
12%       gets previous set FLAG and sets FLAG for the future
13% flag_implicit_skip_nan(prevFLAG)
14%       resets FLAG to previous mode
15%
16% It is used in:
17%       SUMSKIPNAN, MEDIAN, QUANTILES, TRIMEAN
18% and affects many other functions like:
19%       CENTER, KURTOSIS, MAD, MEAN, MOMENT, RMS, SEM, SKEWNESS,
20%       STATISTIC, STD, VAR, ZSCORE etc.
21%
22% The mode is stored in the global variable FLAG_implicit_skip_nan
23% It is recommended to use flag_implicit_skip_nan(1) as default and
24% flag_implicit_skip_nan(0) should be used for exceptional cases only.
25% This feature might disappear without further notice, so you should really not
26% rely on it.
27
28
29%    This program is free software; you can redistribute it and/or modify
30%    it under the terms of the GNU General Public License as published by
31%    the Free Software Foundation; either version 3 of the License, or
32%    (at your option) any later version.
33%
34%    This program is distributed in the hope that it will be useful,
35%    but WITHOUT ANY WARRANTY; without even the implied warranty of
36%    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37%    GNU General Public License for more details.
38%
39%    You should have received a copy of the GNU General Public License
40%    along with this program; if not, write to the Free Software
41%    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
42
43%       $Id: flag_implicit_skip_nan.m 8351 2011-06-24 17:35:07Z carandraug $
44
45%   Copyright (C) 2001-2003,2009 by Alois Schloegl <alois.schloegl@gmail.com>
46%   Copyright (C) 2014-2017 Dynare Team
47%
48%       This function is part of the NaN-toolbox
49%       http://pub.ist.ac.at/~schloegl/matlab/NaN/
50
51
52persistent FLAG_implicit_skip_nan;
53
54%% if strcmp(version,'3.6'), FLAG_implicit_skip_nan=(1==1); end;        %% hack for the use with Freemat3.6
55
56%%% set DEFAULT value of FLAG
57if isempty(FLAG_implicit_skip_nan)
58    FLAG_implicit_skip_nan = (1==1); %logical(1); % logical.m not available on 2.0.16
59end
60
61FLAG = FLAG_implicit_skip_nan;
62if nargin>0
63    FLAG_implicit_skip_nan = (i~=0); %logical(i); %logical.m not available in 2.0.16
64    if (~i)
65        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.')
66    end
67end
68