cancel_i(3PI) Sun Interval Performance Library cancel_i(3PI)NAMEcancel_i - Scaled cancellation.
DESCRIPTION
Y = ALPHA * X .CANCEL. BETA * Y
The operation CANCEL, between two intervals A and B is defined as A
.CANCEL. B = [INF(A)-INF(B),SUP(A)-SUP(B)]
if (INF(A)-INF(B)) <= (SUP(A)-SUP(B)); Otherwise 0.
The routine CANCEL_I scales the interval vector X by the interval ALPHA
and the interval vector Y by BETA, and stores the result of scaled
cancellation in the vector Y. The routine returns immediately if N is
equal to zero.
SYNOPSIS
SUBROUTINE CANCEL_I( X, Y [, ALPHA] [, BETA] )
INTERVAL, INTENT(IN) :: X(:)
INTERVAL, INTENT(INOUT) :: Y(:)
INTERVAL, INTENT(IN), OPTIONAL :: ALPHA, BETA
where
X and Y have shape (N).
ARGUMENTS
X (input)
Array of DIMENSION N.
Unchanged on exit.
Y (input/output)
Array of DIMENSION N.
On exit, Y is overwritten by results of subroutine:
Y = ALPHA * X .CANCEL. BETA * Y
ALPHA (input)
On entry, ALPHA specifies the scalar ALPHA.
Default value is ALPHA = [1,1].
Unchanged on exit.
BETA (input)
On entry, BETA specifies the scalar BETA.
Default value is BETA = [0,0].
Unchanged on exit.
ERRORS
blas_error_alloc
X or Y is unallocated array
blas_error_shape
shape(X) /= shape(Y)
6 Mar 2009 cancel_i(3PI)
