lapack_oct_m::lapack_sygvx Interface Reference

Computes selected eigenvalues, and optionally, eigenvectors of a real generalized symmetric-definite eigenproblem, of the form \(Ax=(\lambda)Bx, ABx=(\lambda)x, \mbox{ or } BAx=(\lambda)x \). Here A and B are assumed to be symmetric and B is also positive definite. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues. More...

Detailed Description

Computes selected eigenvalues, and optionally, eigenvectors of a real generalized symmetric-definite eigenproblem, of the form \(Ax=(\lambda)Bx, ABx=(\lambda)x, \mbox{ or } BAx=(\lambda)x \). Here A and B are assumed to be symmetric and B is also positive definite. Eigenvalues and eigenvectors can be selected by specifying either a range of values or a range of indices for the desired eigenvalues.

Definition at line 387 of file lapack.F90.

Public Member Functions
subroutine	dsygvx (itype, jobz, range, uplo, n, a, lda, b, ldb, vl, vu, il, iu, abstol, m, w, z, ldz, work, lwork, iwork, ifail, info)

Member Function/Subroutine Documentation

dsygvx()

subroutine lapack_oct_m::lapack_sygvx::dsygvx	(	integer, intent(in)	itype,
		character(len=1), intent(in)	jobz,
		character(len=1), intent(in)	range,
		character(len=1), intent(in)	uplo,
		integer, intent(in)	n,
		real(real64), intent(inout)	a,
		integer, intent(in)	lda,
		real(real64), intent(inout)	b,
		integer, intent(in)	ldb,
		real(real64), intent(in)	vl,
		real(real64), intent(in)	vu,
		integer, intent(in)	il,
		integer, intent(in)	iu,
		real(real64), intent(in)	abstol,
		integer, intent(out)	m,
		real(real64), intent(out)	w,
		real(real64), intent(out)	z,
		integer, intent(in)	ldz,
		real(real64), intent(out)	work,
		integer, intent(in)	lwork,
		integer, intent(out)	iwork,
		integer, intent(out)	ifail,
		integer, intent(out)	info
	)

Parameters

[in]	itype	Specifies the problem: 1: A*x = l*B*x 2: A*B*x = l*x 3: B*A*x = l*x
[in]	jobz	N: Compute eigenvalues only; V: Compute eigenvalues and eigenvectors.
[in]	range	A: all eigenval V: all eigenval in (VL,VU] I: IL-th through IU-th eigenval
[in]	uplo	U: Upper triangle of A and B stored L: Lower triangle of A and B stored
[in]	n	The order of the matrix pencil (A,B)
[in,out]	a	a(:) On entry, the symmetric matrix A. On exit, destroyed
[in]	lda	The leading dimension of the array A
[in,out]	b	b(:)
[out]	work	work(:)
[out]	iwork	iwork(1:5*n)
[out]	ifail	ifail(1:n)

Definition at line 388 of file lapack.F90.

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

• math/lapack.F90