# Quadratic matrix multiplication

## Primary tabs

The quadratic product "%&%" is a convenient (and efficient) function for pre- and post-multiplying a matrix B by another matrix A and its transpose A', ie.. ABA'

Quadratic form has several uses (see Quadratic form (statistics)

A %&% B is equivalent to A %% B %% t(A)

Conformability is cA=rB=cB