Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / nan-2.5.5 / nanconv.m

diff --git a/octave_packages/nan-2.5.5/nanconv.m b/octave_packages/nan-2.5.5/nanconv.m
new file mode 100644 (file)
index 0000000..39d46b0
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+++ b/octave_packages/nan-2.5.5/nanconv.m
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+function [C,N,c] = nanconv(X,Y,arg3)
+% NANCONV computes the convolution for data with missing values. 
+%  X and Y can contain missing values encoded with NaN.
+%  NaN's are skipped, NaN do not result in a NaN output. 
+%  The output gives NaN only if there are insufficient input data
+%
+% [...] = NANCONV(X,Y);
+%      calculates 2-dim convolution between X and Y
+% [C]   = NANCONV(X,Y);
+%
+% WARNING: missing values can introduce aliasing - causing unintended results.
+%    Moreover, the behavior of bandpass and highpass filters in case of missing values 
+%    is not fully understood, and might contain some pitfalls.  
+%
+% see also: CONV, NANCONV2, NANFFT, NANFILTER
+
+%      $Id: conv2nan.m 6973 2010-02-28 20:19:12Z schloegl $
+%      Copyright (C) 2000-2005,2010,2011 by Alois Schloegl <alois.schloegl@gmail.com>  
+%       This function is part of the NaN-toolbox
+%       http://pub.ist.ac.at/~schloegl/matlab/NaN/ and 
+%      http://octave.svn.sourceforge.net/viewvc/octave/trunk/octave-forge/extra/NaN/inst/
+
+%    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/>.
+
+
+warning('NANCONV is experimental. For more details see HELP NANCONV');
+
+
+if nargin~=2,
+        fprintf(2,'Error NANCONV2: incorrect number of input arguments\n');
+end;
+
+m = isnan(X);
+n = isnan(Y);
+
+X(m) = 0;
+Y(n) = 0;
+
+C = conv(X,Y);         % 2-dim convolution
+N = conv(real(~m),real(~n));     % normalization term
+c = conv(ones(size(X)),ones(size(Y))); % correction of normalization
+
+if nargout==1,
+        C = C.*c./N;
+elseif nargout==2,
+        N = N./c;
+end;
+