dqrt15()

subroutine dqrt15	(	integer	scale,
		integer	rksel,
		integer	m,
		integer	n,
		integer	nrhs,
		double precision, dimension( lda, * )	a,
		integer	lda,
		double precision, dimension( ldb, * )	b,
		integer	ldb,
		double precision, dimension( * )	s,
		integer	rank,
		double precision	norma,
		double precision	normb,
		integer, dimension( 4 )	iseed,
		double precision, dimension( lwork )	work,
		integer	lwork
	)

DQRT15

Purpose:

 DQRT15 generates a matrix with full or deficient rank and of various
 norms.

Parameters

[in]	SCALE	SCALE is INTEGER SCALE = 1: normally scaled matrix SCALE = 2: matrix scaled up SCALE = 3: matrix scaled down
[in]	RKSEL	RKSEL is INTEGER RKSEL = 1: full rank matrix RKSEL = 2: rank-deficient matrix
[in]	M	M is INTEGER The number of rows of the matrix A.
[in]	N	N is INTEGER The number of columns of A.
[in]	NRHS	NRHS is INTEGER The number of columns of B.
[out]	A	A is DOUBLE PRECISION array, dimension (LDA,N) The M-by-N matrix A.
[in]	LDA	LDA is INTEGER The leading dimension of the array A.
[out]	B	B is DOUBLE PRECISION array, dimension (LDB, NRHS) A matrix that is in the range space of matrix A.
[in]	LDB	LDB is INTEGER The leading dimension of the array B.
[out]	S	S is DOUBLE PRECISION array, dimension MIN(M,N) Singular values of A.
[out]	RANK	RANK is INTEGER number of nonzero singular values of A.
[out]	NORMA	NORMA is DOUBLE PRECISION one-norm of A.
[out]	NORMB	NORMB is DOUBLE PRECISION one-norm of B.
[in,out]	ISEED	ISEED is integer array, dimension (4) seed for random number generator.
[out]	WORK	WORK is DOUBLE PRECISION array, dimension (LWORK)
[in]	LWORK	LWORK is INTEGER length of work space required. LWORK >= MAX(M+MIN(M,N),NRHS*MIN(M,N),2*N+M)

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.