PCAKLM Principal Component Analysis/KarhunenLoeve Mapping(PCA or MCA of overall/mean covariance matrix) [W,FRAC] = PCAKLM(TYPE,A,N)
DescriptionPerforms a principal component analysis (PCA) or minor component analysis (MCA) on the overall or mean class covariance matrix (weighted by the class prior probabilities). It finds a rotation of the dataset A to an Ndimensional 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 = PCAKLM(A,TYPE,0) Returns the cumulative fraction of the explained variance. V(N) is the cumulative fraction of the explained variance by using N eigenvectors. This function should not be called directly, only trough PCA or KLM. Use FISHERM for optimizing the linear class separability (LDA). See alsomappings, datasets, pcldc, klldc, pcam, klm, fisherm,
