LASDQ: computes the singular value decomposition (SVD) of a real (upper or lower) bidiagonal matrix with diagonal D and offdiagonal E, accumulating the transformations if desired. Letting B denote the input bidiagonal matrix, the algorithm computes orthogonal matrices Q and P such that B = Q * S * P**T (P**T denotes the transpose of P). The singular values S are overwritten on D. The input matrix U is changed to U * Q if desired. The input matrix VT is changed to P**T * VT if desired. The input matrix C is changed to Q**T * C if desired. See "Computing Small Singular Values of Bidiagonal Matrices With Guaranteed High Relative Accuracy," by J. Demmel and W. Kahan, LAPACK Working Note #3, for a detailed description of the algorithm. More...

Public Member Functions
pure subroutine	dlasdq (uplo, sqre, n, ncvt, nru, ncc, d, e, vt, ldvt, u, ldu, c, ldc, work, info)

	la_dlasdq

	la_qlasdq

pure subroutine	slasdq (uplo, sqre, n, ncvt, nru, ncc, d, e, vt, ldvt, u, ldu, c, ldc, work, info)

	la_slasdq

Detailed Description

LASDQ: computes the singular value decomposition (SVD) of a real (upper or lower) bidiagonal matrix with diagonal D and offdiagonal E, accumulating the transformations if desired. Letting B denote the input bidiagonal matrix, the algorithm computes orthogonal matrices Q and P such that B = Q * S * P**T (P**T denotes the transpose of P). The singular values S are overwritten on D. The input matrix U is changed to U * Q if desired. The input matrix VT is changed to P**T * VT if desired. The input matrix C is changed to Q**T * C if desired. See "Computing Small Singular Values of Bidiagonal Matrices With Guaranteed High Relative Accuracy," by J. Demmel and W. Kahan, LAPACK Working Note #3, for a detailed description of the algorithm.

Member Function/Subroutine Documentation

◆ dlasdq()

pure subroutine la_lapack::lasdq::dlasdq	(	character, intent(in)	uplo,
		integer(ilp), intent(in)	sqre,
		integer(ilp), intent(in)	n,
		integer(ilp), intent(in)	ncvt,
		integer(ilp), intent(in)	nru,
		integer(ilp), intent(in)	ncc,
		real(dp), dimension(*), intent(inout)	d,
		real(dp), dimension(*), intent(inout)	e,
		real(dp), dimension(ldvt,*), intent(inout)	vt,
		integer(ilp), intent(in)	ldvt,
		real(dp), dimension(ldu,*), intent(inout)	u,
		integer(ilp), intent(in)	ldu,
		real(dp), dimension(ldc,*), intent(inout)	c,
		integer(ilp), intent(in)	ldc,
		real(dp), dimension(*), intent(out)	work,
		integer(ilp), intent(out)	info
	)

◆ la_dlasdq()

la_lapack::lasdq::la_dlasdq

◆ la_qlasdq()

la_lapack::lasdq::la_qlasdq

◆ la_slasdq()

la_lapack::lasdq::la_slasdq

◆ slasdq()

pure subroutine la_lapack::lasdq::slasdq	(	character, intent(in)	uplo,
		integer(ilp), intent(in)	sqre,
		integer(ilp), intent(in)	n,
		integer(ilp), intent(in)	ncvt,
		integer(ilp), intent(in)	nru,
		integer(ilp), intent(in)	ncc,
		real(sp), dimension(*), intent(inout)	d,
		real(sp), dimension(*), intent(inout)	e,
		real(sp), dimension(ldvt,*), intent(inout)	vt,
		integer(ilp), intent(in)	ldvt,
		real(sp), dimension(ldu,*), intent(inout)	u,
		integer(ilp), intent(in)	ldu,
		real(sp), dimension(ldc,*), intent(inout)	c,
		integer(ilp), intent(in)	ldc,
		real(sp), dimension(*), intent(out)	work,
		integer(ilp), intent(out)	info
	)

The documentation for this interface was generated from the following file:

la_lapack.f90