STEBZ: computes the eigenvalues of a symmetric tridiagonal matrix T. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues. To avoid overflow, the matrix must be scaled so that its largest element is no greater than overflow**(1/2) * underflow**(1/4) in absolute value, and for greatest accuracy, it should not be much smaller than that. See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal Matrix", Report CS41, Computer Science Dept., Stanford University, July 21, 1966. More...

Public Member Functions
pure subroutine	dstebz (range, order, n, vl, vu, il, iu, abstol, d, e, m, nsplit, w, iblock, isplit, work, iwork, info)

	la_dstebz

	la_qstebz

pure subroutine	sstebz (range, order, n, vl, vu, il, iu, abstol, d, e, m, nsplit, w, iblock, isplit, work, iwork, info)

	la_sstebz

Detailed Description

STEBZ: computes the eigenvalues of a symmetric tridiagonal matrix T. The user may ask for all eigenvalues, all eigenvalues in the half-open interval (VL, VU], or the IL-th through IU-th eigenvalues. To avoid overflow, the matrix must be scaled so that its largest element is no greater than overflow**(1/2) * underflow**(1/4) in absolute value, and for greatest accuracy, it should not be much smaller than that. See W. Kahan "Accurate Eigenvalues of a Symmetric Tridiagonal Matrix", Report CS41, Computer Science Dept., Stanford University, July 21, 1966.

Member Function/Subroutine Documentation

◆ dstebz()

pure subroutine la_lapack::stebz::dstebz	(	character, intent(in)	range,
		character, intent(in)	order,
		integer(ilp), intent(in)	n,
		real(dp), intent(in)	vl,
		real(dp), intent(in)	vu,
		integer(ilp), intent(in)	il,
		integer(ilp), intent(in)	iu,
		real(dp), intent(in)	abstol,
		real(dp), dimension(*), intent(in)	d,
		real(dp), dimension(*), intent(in)	e,
		integer(ilp), intent(out)	m,
		integer(ilp), intent(out)	nsplit,
		real(dp), dimension(*), intent(out)	w,
		integer(ilp), dimension(*), intent(out)	iblock,
		integer(ilp), dimension(*), intent(out)	isplit,
		real(dp), dimension(*), intent(out)	work,
		integer(ilp), dimension(*), intent(out)	iwork,
		integer(ilp), intent(out)	info
	)

◆ la_dstebz()

la_lapack::stebz::la_dstebz

◆ la_qstebz()

la_lapack::stebz::la_qstebz

◆ la_sstebz()

la_lapack::stebz::la_sstebz

◆ sstebz()

pure subroutine la_lapack::stebz::sstebz	(	character, intent(in)	range,
		character, intent(in)	order,
		integer(ilp), intent(in)	n,
		real(sp), intent(in)	vl,
		real(sp), intent(in)	vu,
		integer(ilp), intent(in)	il,
		integer(ilp), intent(in)	iu,
		real(sp), intent(in)	abstol,
		real(sp), dimension(*), intent(in)	d,
		real(sp), dimension(*), intent(in)	e,
		integer(ilp), intent(out)	m,
		integer(ilp), intent(out)	nsplit,
		real(sp), dimension(*), intent(out)	w,
		integer(ilp), dimension(*), intent(out)	iblock,
		integer(ilp), dimension(*), intent(out)	isplit,
		real(sp), dimension(*), intent(out)	work,
		integer(ilp), dimension(*), intent(out)	iwork,
		integer(ilp), intent(out)	info
	)

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

la_lapack.f90