The @QRFACTOR function returns a QR factorization of a matrix.  The syntax for @QRFACTOR is:

Q, R = @QRFACTOR( A);

where A = QR, with R being upper triangular and Q being orthogonal (i.e., Q'Q is the identity matrix).  The matrices must all be defined on dense sets, with A and Q being m x n matrices and R an n x n matrix.   @QRFACTOR may only be used in calc sections.