hbgvd Interface

public interface hbgvd

HBGVD computes all the eigenvalues, and optionally, the eigenvectors of a complex generalized Hermitian-definite banded eigenproblem, of the form Ax=(lambda)B*x. Here A and B are assumed to be Hermitian and banded, and B is also positive definite. If eigenvectors are desired, it uses a divide and conquer algorithm. The divide and conquer algorithm makes very mild assumptions about floating point arithmetic. It will work on machines with a guard digit in add/subtract, or on those binary machines without guard digits which subtract like the Cray X-MP, Cray Y-MP, Cray C-90, or Cray-2. It could conceivably fail on hexadecimal or decimal machines without guard digits, but we know of none.


Subroutines

public pure subroutine chbgvd(jobz, uplo, n, ka, kb, ab, ldab, bb, ldbb, w, z, ldz, work, lwork, rwork, lrwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: ka
integer(kind=ilp), intent(in) :: kb
complex(kind=sp), intent(inout) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
complex(kind=sp), intent(inout) :: bb(ldbb,*)
integer(kind=ilp), intent(in) :: ldbb
real(kind=sp), intent(out) :: w(*)
complex(kind=sp), intent(out) :: z(ldz,*)
integer(kind=ilp), intent(in) :: ldz
complex(kind=sp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
real(kind=sp), intent(out) :: rwork(*)
integer(kind=ilp), intent(in) :: lrwork
integer(kind=ilp), intent(out) :: iwork(*)
integer(kind=ilp), intent(in) :: liwork
integer(kind=ilp), intent(out) :: info

public pure subroutine zhbgvd(jobz, uplo, n, ka, kb, ab, ldab, bb, ldbb, w, z, ldz, work, lwork, rwork, lrwork, iwork, liwork, info)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: jobz
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: ka
integer(kind=ilp), intent(in) :: kb
complex(kind=dp), intent(inout) :: ab(ldab,*)
integer(kind=ilp), intent(in) :: ldab
complex(kind=dp), intent(inout) :: bb(ldbb,*)
integer(kind=ilp), intent(in) :: ldbb
real(kind=dp), intent(out) :: w(*)
complex(kind=dp), intent(out) :: z(ldz,*)
integer(kind=ilp), intent(in) :: ldz
complex(kind=dp), intent(out) :: work(*)
integer(kind=ilp), intent(in) :: lwork
real(kind=dp), intent(out) :: rwork(*)
integer(kind=ilp), intent(in) :: lrwork
integer(kind=ilp), intent(out) :: iwork(*)
integer(kind=ilp), intent(in) :: liwork
integer(kind=ilp), intent(out) :: info

Module Procedures

public interface stdlib_chbgvd()

Arguments

None

public interface stdlib_zhbgvd()

Arguments

None