caxpy()

subroutine caxpy	(	integer	n,
		complex	ca,
		complex, dimension(*)	cx,
		integer	incx,
		complex, dimension(*)	cy,
		integer	incy
	)

CAXPY

Purpose:

    CAXPY constant times a vector plus a vector.

Parameters

[in]	N	N is INTEGER number of elements in input vector(s)
[in]	CA	CA is COMPLEX On entry, CA specifies the scalar alpha.
[in]	CX	CX is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]	INCX	INCX is INTEGER storage spacing between elements of CX
[in,out]	CY	CY is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
[in]	INCY	INCY is INTEGER storage spacing between elements of CY

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Further Details:

     jack dongarra, linpack, 3/11/78.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 87 of file caxpy.f.

*
*  -- Reference BLAS level1 routine --
*  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
*     .. Scalar Arguments ..
      COMPLEX CA
      INTEGER INCX,INCY,N
*     ..
*     .. Array Arguments ..
      COMPLEX CX(*),CY(*)
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER I,IX,IY
*     ..
*     .. External Functions ..
      REAL SCABS1
      EXTERNAL scabs1
*     ..
      IF (n.LE.0) RETURN
      IF (scabs1(ca).EQ.0.0e+0) RETURN
      IF (incx.EQ.1 .AND. incy.EQ.1) THEN
*
*        code for both increments equal to 1
*
         DO i = 1,n
            cy(i) = cy(i) + ca*cx(i)
         END DO
      ELSE
*
*        code for unequal increments or equal increments
*          not equal to 1
*
         ix = 1
         iy = 1
         IF (incx.LT.0) ix = (-n+1)*incx + 1
         IF (incy.LT.0) iy = (-n+1)*incy + 1
         DO i = 1,n
            cy(iy) = cy(iy) + ca*cx(ix)
            ix = ix + incx
            iy = iy + incy
         END DO
      END IF
*
      RETURN
*
*     End of CAXPY
*