The householder algorithm and applications
Garry Helzer · ACM SIGAPL APL Quote Quad · 1979
An APL implementation of the Householder algorithm for the QR-factorization of a general matrix is given. Applications of the algorithm to the solution of underdetermined linear systems are given. The applications involve ordinary solutions, least squares solutions, and mixed ordinary least squares solutions.The QR-algorithm for estimating the eigenvalues of a matrix is not discussed; however the algorithm presented here can be used as a utility function for the QR-algorithm.