[Q,R] = qrdelete(Q,R,j)
[Q,R] = qrdelete(Q,R,j), where the inputs Q and R are the original QR factorization of a matrix A, returns Q and R as the QR factorization of the matrix A with columns A(:,j) removed.
qrdelete uses a series of Givens rotations to zero out the appropriate elements of the factorization.
qr,qrinsert
(c) Copyright 1994 by The MathWorks, Inc.