Unfoldm

Purpose

Unfolds an augmented matrix for MPCA.

Synopsis

xmpca = unfoldm(xaug,nsamp)

Description

UNFOLDM unfolds the input matrix xaug to create a matrix of unfolded row vectors xmpca for MPCA. xaug contains nsamp matrices Aj augmented such that [xaug] = [A1; A2; ...; Ansamp]. For example, for xaug of size (nsamp\*m by n) each matrix Aj is of size m by n. For Aj each m by 1 column ai is transposed and augmented such that [bj] = [a1', a2', ..., an'] and [xmpca] = [b1; b2; ...; bnsamp]. Note: the Aj should all be the same size.

Examples

a = [1     2     3
     4     5     6
    -1    -2    -3
    -4    -5    -6]
xmpca = unfoldm(a,2)
xmpca = [1     4     2     5     3     6
        -1    -4    -2    -5    -3    -6]

See Also

gscale, mpca, pca, reshape