Q = orth(X)
Q = orth(X) returns an orthonormal basis for the range of X. The columns of Q span the same space as the columns of X, and the columns of Q are orthogonal, so that
Q'*Q = eye(min(size(X)))The number of columns of
Q is the rank of X.
null, qr
(c) Copyright 1994 by The MathWorks, Inc.