Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/nan-2.5.5/classify.m b/octave_packages/nan-2.5.5/classify.m
new file mode 100644 (file)
index 0000000..0481af8
--- /dev/null
+++ b/octave_packages/nan-2.5.5/classify.m
@@ -0,0 +1,77 @@
+function [CLASS,ERR,POSTERIOR,LOGP,COEF]=classify(sample,training,classlabel,TYPE)
+% CLASSIFY classifies sample data into categories 
+% defined by the training data and its group information 
+%
+%  CLASS = classify(sample, training, group) 
+%  CLASS = classify(sample, training, group, TYPE) 
+%  [CLASS,ERR,POSTERIOR,LOGP,COEF] = CLASSIFY(...) 
+%
+%  CLASS contains the assigned group. 
+%  ERR is the classification error on the training set weighted by the 
+%      prior propability of each group. 
+%
+%  The same classifier as in TRAIN_SC are supported. 
+%
+% ATTENTION: no cross-validation is applied, therefore the 
+%    classification error is too optimistic (overfitting). 
+%    Use XVAL instead to obtain cross-validated performance. 
+% 
+% see also: TRAIN_SC, TEST_SC, XVAL
+%
+% References: 
+% [1] R. Duda, P. Hart, and D. Stork, Pattern Classification, second ed. 
+%       John Wiley & Sons, 2001. 
+
+%      $Id$
+%      Copyright (C) 2008,2009 by Alois Schloegl <alois.schloegl@gmail.com>    
+%       This function is part of the NaN-toolbox
+%       http://pub.ist.ac.at/~schloegl/matlab/NaN/
+
+% 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.
+
+if nargin<4
+       TYPE = 'linear';
+end; 
+
+if strcmp(TYPE,'linear')
+       TYPE = 'LDA';
+elseif strcmp(TYPE,'quadratic')
+       TYPE = 'QDA2'; % result is closer to Matlab 
+elseif strcmp(TYPE,'diagLinear')
+       TYPE = 'NBC';
+elseif strcmp(TYPE,'diagQuadratic')
+       TYPE = 'NBC';
+elseif strcmp(TYPE,'mahalanobis')
+       TYPE = 'MDA';
+end;   
+
+[group,I,classlabel] = unique(classlabel);
+
+CC = train_sc(training,classlabel,TYPE); 
+R  = test_sc(CC,sample);
+CLASS = group(R.classlabel); 
+
+if nargout>1,
+       R  = test_sc(CC,training,[],classlabel);
+       ERR = 1-R.ACC; 
+end; 
+
+if nargout>2,
+       warning('output arguments POSTERIOR,LOGP and COEF not supported')
+       POSTERIOR = [];
+       LOGP = [];
+       COEF = [];
+end; 
+