larfg Interface

public interface larfg

LARFG generates a complex elementary reflector H of order n, such that HH * ( alpha ) = ( beta ), HH * H = I. ( x ) ( 0 ) where alpha and beta are scalars, with beta real, and x is an (n-1)-element complex vector. H is represented in the form H = I - tau * ( 1 ) * ( 1 v**H ) , ( v ) where tau is a complex scalar and v is a complex (n-1)-element vector. Note that H is not hermitian. If the elements of x are all zero and alpha is real, then tau = 0 and H is taken to be the unit matrix. Otherwise 1 <= real(tau) <= 2 and abs(tau-1) <= 1 .


Subroutines

public pure subroutine clarfg(n, alpha, x, incx, tau)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
complex(kind=sp), intent(inout) :: alpha
complex(kind=sp), intent(inout) :: x(*)
integer(kind=ilp), intent(in) :: incx
complex(kind=sp), intent(out) :: tau

public pure subroutine dlarfg(n, alpha, x, incx, tau)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=dp), intent(inout) :: alpha
real(kind=dp), intent(inout) :: x(*)
integer(kind=ilp), intent(in) :: incx
real(kind=dp), intent(out) :: tau

public pure subroutine slarfg(n, alpha, x, incx, tau)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
real(kind=sp), intent(inout) :: alpha
real(kind=sp), intent(inout) :: x(*)
integer(kind=ilp), intent(in) :: incx
real(kind=sp), intent(out) :: tau

public pure subroutine zlarfg(n, alpha, x, incx, tau)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
complex(kind=dp), intent(inout) :: alpha
complex(kind=dp), intent(inout) :: x(*)
integer(kind=ilp), intent(in) :: incx
complex(kind=dp), intent(out) :: tau

Module Procedures

public interface stdlib_clarfg()

Arguments

None

public interface stdlib_dlarfg()

Arguments

None

public interface stdlib_slarfg()

Arguments

None

public interface stdlib_zlarfg()

Arguments

None