A Direct Solution for Pairwise Rotations in Kaiser's Varimax Method
Klaas Nevels · Psychometrika · 1986
The present note contains a completing-the-squares type approach to the varimax rotation problem. This approach yields a direct proof of global optimality of a solution for optimal rotation in a plane. Because varimax rotation can be interpreted as diagonalization of a set of symmetric matrices, the present solution also applies to the diagonalization problem.