We present an analysis of a constrained principal components analysis netwo
rk that identifies the common factors in data sets in a manner similar to p
rincipal factor analysis. This network responds to the covariance of the in
put data (not both variance and covariance as in PCA) and so is resistant t
o noise and varying levels of power on the inputs. The network naturally le
nds itself to the sparse coding of data, however, by enforcing this sparsen
ess further we are able to decipher dual components in data. (C) 1998 Elsev
ier Science B.V. All rights reserved.