This subroutine computes the I-th updated eigenvalue of a symmetric rank-one modification to a diagonal matrix whose elements are given in the array d, and that D(i) < D(j) for i < j and that RHO > 0. This is arranged by the calling routine, and is no loss in generality. The rank-one modified system is thus diag( D ) + RHO * Z * Z_transpose. where we assume the Euclidean norm of Z is 1. The method consists of approximating the rational functions in the secular equation by simpler interpolating rational functions. More...

Public Member Functions
pure subroutine	dlaed4 (n, i, d, z, delta, rho, dlam, info)

	la_dlaed4

	la_qlaed4

pure subroutine	slaed4 (n, i, d, z, delta, rho, dlam, info)

	la_slaed4

Detailed Description

This subroutine computes the I-th updated eigenvalue of a symmetric rank-one modification to a diagonal matrix whose elements are given in the array d, and that D(i) < D(j) for i < j and that RHO > 0. This is arranged by the calling routine, and is no loss in generality. The rank-one modified system is thus diag( D ) + RHO * Z * Z_transpose. where we assume the Euclidean norm of Z is 1. The method consists of approximating the rational functions in the secular equation by simpler interpolating rational functions.

Member Function/Subroutine Documentation

◆ dlaed4()

pure subroutine la_lapack::laed4::dlaed4	(	integer(ilp), intent(in)	n,
		integer(ilp), intent(in)	i,
		real(dp), dimension(*), intent(in)	d,
		real(dp), dimension(*), intent(in)	z,
		real(dp), dimension(*), intent(out)	delta,
		real(dp), intent(in)	rho,
		real(dp), intent(out)	dlam,
		integer(ilp), intent(out)	info
	)

◆ la_dlaed4()

la_lapack::laed4::la_dlaed4

◆ la_qlaed4()

la_lapack::laed4::la_qlaed4

◆ la_slaed4()

la_lapack::laed4::la_slaed4

◆ slaed4()

pure subroutine la_lapack::laed4::slaed4	(	integer(ilp), intent(in)	n,
		integer(ilp), intent(in)	i,
		real(sp), dimension(*), intent(in)	d,
		real(sp), dimension(*), intent(in)	z,
		real(sp), dimension(*), intent(out)	delta,
		real(sp), intent(in)	rho,
		real(sp), intent(out)	dlam,
		integer(ilp), intent(out)	info
	)

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

la_lapack.f90