lassq Interface

public interface lassq

LASSQ returns the values scl and smsq such that ( scl2 )*smsq = x( 1 )2 +...+ x( n )2 + ( scale2 )sumsq, where x( i ) = X( 1 + ( i - 1 )INCX ). The value of sumsq is assumed to be non-negative. scale and sumsq must be supplied in SCALE and SUMSQ and scl and smsq are overwritten on SCALE and SUMSQ respectively. If scale * sqrt( sumsq ) > tbig then we require: scale >= sqrt( TINYEPS ) / sbig on entry, and if 0 < scale * sqrt( sumsq ) < tsml then we require: scale <= sqrt( HUGE ) / ssml on entry, where tbig -- upper threshold for values whose square is representable; sbig -- scaling constant for big numbers; \see la_constants.f90 tsml -- lower threshold for values whose square is representable; ssml -- scaling constant for small numbers; \see la_constants.f90 and TINYEPS -- tiniest representable number; HUGE -- biggest representable number.


Subroutines

public pure subroutine classq(n, x, incx, scl, sumsq)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
complex(kind=sp), intent(in) :: x(*)
integer(kind=ilp), intent(in) :: incx
real(kind=sp), intent(inout) :: scl
real(kind=sp), intent(inout) :: sumsq

public pure subroutine dlassq(n, x, incx, scl, sumsq)

Arguments

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

public pure subroutine slassq(n, x, incx, scl, sumsq)

Arguments

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

public pure subroutine zlassq(n, x, incx, scl, sumsq)

Arguments

Type IntentOptional Attributes Name
integer(kind=ilp), intent(in) :: n
complex(kind=dp), intent(in) :: x(*)
integer(kind=ilp), intent(in) :: incx
real(kind=dp), intent(inout) :: scl
real(kind=dp), intent(inout) :: sumsq

Module Procedures

public interface stdlib_classq()

Arguments

None

public interface stdlib_dlassq()

Arguments

None

public interface stdlib_slassq()

Arguments

None

public interface stdlib_zlassq()

Arguments

None