Principal-Components Analysis: Constrained-Optimization Approach
In Section 8.4, we used perturbation theory to derive the PCA.In this problem we address this same issue from the perspective of a constrained-optimization approach.
Let x denote an m-dimensional zero-mean data vector and w denote an adjustable parameter vector of the same dimension m.
Let σ2 denote the variance of the projection of the data vector x onto the parameter vector w.