latrd Interface

public interface latrd

LATRD reduces NB rows and columns of a complex Hermitian matrix A to Hermitian tridiagonal form by a unitary similarity transformation Q**H * A * Q, and returns the matrices V and W which are needed to apply the transformation to the unreduced part of A. If UPLO = 'U', LATRD reduces the last NB rows and columns of a matrix, of which the upper triangle is supplied; if UPLO = 'L', LATRD reduces the first NB rows and columns of a matrix, of which the lower triangle is supplied. This is an auxiliary routine called by CHETRD.


Subroutines

public pure subroutine clatrd(uplo, n, nb, a, lda, e, tau, w, ldw)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: nb
complex(kind=sp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=sp), intent(out) :: e(*)
complex(kind=sp), intent(out) :: tau(*)
complex(kind=sp), intent(out) :: w(ldw,*)
integer(kind=ilp), intent(in) :: ldw

public pure subroutine dlatrd(uplo, n, nb, a, lda, e, tau, w, ldw)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: nb
real(kind=dp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=dp), intent(out) :: e(*)
real(kind=dp), intent(out) :: tau(*)
real(kind=dp), intent(out) :: w(ldw,*)
integer(kind=ilp), intent(in) :: ldw

public pure subroutine slatrd(uplo, n, nb, a, lda, e, tau, w, ldw)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: nb
real(kind=sp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=sp), intent(out) :: e(*)
real(kind=sp), intent(out) :: tau(*)
real(kind=sp), intent(out) :: w(ldw,*)
integer(kind=ilp), intent(in) :: ldw

public pure subroutine zlatrd(uplo, n, nb, a, lda, e, tau, w, ldw)

Arguments

Type IntentOptional Attributes Name
character(len=1), intent(in) :: uplo
integer(kind=ilp), intent(in) :: n
integer(kind=ilp), intent(in) :: nb
complex(kind=dp), intent(inout) :: a(lda,*)
integer(kind=ilp), intent(in) :: lda
real(kind=dp), intent(out) :: e(*)
complex(kind=dp), intent(out) :: tau(*)
complex(kind=dp), intent(out) :: w(ldw,*)
integer(kind=ilp), intent(in) :: ldw

Module Procedures

public interface stdlib_clatrd()

Arguments

None

public interface stdlib_dlatrd()

Arguments

None

public interface stdlib_slatrd()

Arguments

None

public interface stdlib_zlatrd()

Arguments

None