labrd Interface

public interface labrd

LABRD reduces the first NB rows and columns of a complex general m by n matrix A to upper or lower real bidiagonal form by a unitary transformation Q**H * A * P, and returns the matrices X and Y which are needed to apply the transformation to the unreduced part of A. If m >= n, A is reduced to upper bidiagonal form; if m < n, to lower bidiagonal form. This is an auxiliary routine called by CGEBRD


Subroutines

public pure subroutine clabrd(m, n, nb, a, lda, d, e, tauq, taup, x, ldx, y, ldy)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
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) :: d(*)
real(kind=sp), intent(out) :: e(*)
complex(kind=sp), intent(out) :: tauq(*)
complex(kind=sp), intent(out) :: taup(*)
complex(kind=sp), intent(out) :: x(ldx,*)
integer(kind=ilp), intent(in) :: ldx
complex(kind=sp), intent(out) :: y(ldy,*)
integer(kind=ilp), intent(in) :: ldy

public pure subroutine dlabrd(m, n, nb, a, lda, d, e, tauq, taup, x, ldx, y, ldy)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
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) :: d(*)
real(kind=dp), intent(out) :: e(*)
real(kind=dp), intent(out) :: tauq(*)
real(kind=dp), intent(out) :: taup(*)
real(kind=dp), intent(out) :: x(ldx,*)
integer(kind=ilp), intent(in) :: ldx
real(kind=dp), intent(out) :: y(ldy,*)
integer(kind=ilp), intent(in) :: ldy

public pure subroutine slabrd(m, n, nb, a, lda, d, e, tauq, taup, x, ldx, y, ldy)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
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) :: d(*)
real(kind=sp), intent(out) :: e(*)
real(kind=sp), intent(out) :: tauq(*)
real(kind=sp), intent(out) :: taup(*)
real(kind=sp), intent(out) :: x(ldx,*)
integer(kind=ilp), intent(in) :: ldx
real(kind=sp), intent(out) :: y(ldy,*)
integer(kind=ilp), intent(in) :: ldy

public pure subroutine zlabrd(m, n, nb, a, lda, d, e, tauq, taup, x, ldx, y, ldy)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: m
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) :: d(*)
real(kind=dp), intent(out) :: e(*)
complex(kind=dp), intent(out) :: tauq(*)
complex(kind=dp), intent(out) :: taup(*)
complex(kind=dp), intent(out) :: x(ldx,*)
integer(kind=ilp), intent(in) :: ldx
complex(kind=dp), intent(out) :: y(ldy,*)
integer(kind=ilp), intent(in) :: ldy

Module Procedures

public interface stdlib_clabrd()

Arguments

None

public interface stdlib_dlabrd()

Arguments

None

public interface stdlib_slabrd()

Arguments

None

public interface stdlib_zlabrd()

Arguments

None