Note on Convergence of Minres.

Minres is an interactive least-squares factor, analytic procedure that minimizes the sum-of-squares of the off-diagonal residuals of the correlation matrix. The procedure solves successively for the rows (or the elements of the columns) of the factor pattern. Some versions of Minres proceed by replacing the solved row back into the pattern immediately after each step, but these procedures do not guarantee convergence. Application of the alternating least-squares procedure is recommended. The original solution by Comrey and Ahumada (1964) is correct.