%KLM Karhunen-Loeve Mapping (PCA or MCA of mean covariance matrix) % % [W,FRAC] = KLM(A,N) % [W,N] = KLM(A,FRAC) % % INPUT % A Dataset % N or FRAC Number of dimensions (>= 1) or fraction of variance (< 1) % to retain; if > 0, perform PCA; otherwise MCA. % Default: N = inf. % % OUTPUT % W Affine Karhunen-Loeve mapping % FRAC or N Fraction of variance or number of dimensions retained. % % DESCRIPTION % The Karhunen-Loeve Mapping performs a principal component analysis % (PCA) or minor component analysis (MCA) on the mean class covariance % matrix (weighted by the class prior probabilities). It finds a % rotation of the dataset A to an N-dimensional linear subspace such % that at least (for PCA) or at most (for MCA) a fraction FRAC of the % total variance is preserved. % % PCA is applied when N (or FRAC) >= 0; MCA when N (or FRAC) < 0. If N % is given (abs(N) >= 1), FRAC is optimised. If FRAC is given % (abs(FRAC) < 1), N is optimised. % % Objects in a new dataset B can be mapped by B*W, W*B or by % A*KLM([],N)*B. Default (N = inf): the features are decorrelated and % ordered, but no feature reduction is performed. % % ALTERNATIVE % % V = KLM(A,0) % % Returns the cummulative fraction of the explained variance. V(N) is % the cumulative fraction of the explained variance by using N % eigenvectors. % % Use PCA for a principal component analysis on the total data % covariance. Use FISHERM for optimizing the linear class % separability (LDA). % % This function is basically a wrapper around pcaklm.m. % % SEE ALSO (PRTools Guide) % MAPPINGS, DATASETS, PCAKLM, PCLDC, KLLDC, PCAM, FISHERM % Copyright: R.P.W. Duin, r.p.w.duin@37steps.com % Faculty EWI, Delft University of Technology % P.O. Box 5031, 2600 GA Delft, The Netherlands % $Id: klm.m,v 1.2 2006/03/08 22:06:58 duin Exp $ function [w,truefrac] = klm (varargin) [w,truefrac] = pcaklm(mfilename,varargin{:}); return