dqpt01()

double precision function dqpt01	(	integer	M,
		integer	N,
		integer	K,
		double precision, dimension( lda, * )	A,
		double precision, dimension( lda, * )	AF,
		integer	LDA,
		double precision, dimension( * )	TAU,
		integer, dimension( * )	JPVT,
		double precision, dimension( lwork )	WORK,
		integer	LWORK
	)

DQPT01

Purpose:

 DQPT01 tests the QR-factorization with pivoting of a matrix A.  The
 array AF contains the (possibly partial) QR-factorization of A, where
 the upper triangle of AF(1:k,1:k) is a partial triangular factor,
 the entries below the diagonal in the first k columns are the
 Householder vectors, and the rest of AF contains a partially updated
 matrix.

 This function returns ||A*P - Q*R||/(||norm(A)||*eps*M)

Parameters

[in]	M	M is INTEGER The number of rows of the matrices A and AF.
[in]	N	N is INTEGER The number of columns of the matrices A and AF.
[in]	K	K is INTEGER The number of columns of AF that have been reduced to upper triangular form.
[in]	A	A is DOUBLE PRECISION array, dimension (LDA, N) The original matrix A.
[in]	AF	AF is DOUBLE PRECISION array, dimension (LDA,N) The (possibly partial) output of DGEQPF. The upper triangle of AF(1:k,1:k) is a partial triangular factor, the entries below the diagonal in the first k columns are the Householder vectors, and the rest of AF contains a partially updated matrix.
[in]	LDA	LDA is INTEGER The leading dimension of the arrays A and AF.
[in]	TAU	TAU is DOUBLE PRECISION array, dimension (K) Details of the Householder transformations as returned by DGEQPF.
[in]	JPVT	JPVT is INTEGER array, dimension (N) Pivot information as returned by DGEQPF.
[out]	WORK	WORK is DOUBLE PRECISION array, dimension (LWORK)
[in]	LWORK	LWORK is INTEGER The length of the array WORK. LWORK >= M*N+N.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.