*> \brief \b CSCAL * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * * Definition: * =========== * * SUBROUTINE CSCAL(N,CA,CX,INCX) * * .. Scalar Arguments .. * COMPLEX CA * INTEGER INCX,N * .. * .. Array Arguments .. * COMPLEX CX(*) * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> CSCAL scales a vector by a constant. *> \endverbatim * * Arguments: * ========== * *> \param[in] N *> \verbatim *> N is INTEGER *> number of elements in input vector(s) *> \endverbatim *> *> \param[in] CA *> \verbatim *> CA is COMPLEX *> On entry, CA specifies the scalar alpha. *> \endverbatim *> *> \param[in,out] CX *> \verbatim *> CX is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCX ) ) *> \endverbatim *> *> \param[in] INCX *> \verbatim *> INCX is INTEGER *> storage spacing between elements of CX *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup complex_blas_level1 * *> \par Further Details: * ===================== *> *> \verbatim *> *> jack dongarra, linpack, 3/11/78. *> modified 3/93 to return if incx .le. 0. *> modified 12/3/93, array(1) declarations changed to array(*) *> \endverbatim *> * ===================================================================== SUBROUTINE CSCAL(N,CA,CX,INCX) * * -- 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,N * .. * .. Array Arguments .. COMPLEX CX(*) * .. * * ===================================================================== * * .. Local Scalars .. INTEGER I,NINCX * .. IF (N.LE.0 .OR. INCX.LE.0) RETURN IF (INCX.EQ.1) THEN * * code for increment equal to 1 * DO I = 1,N CX(I) = CA*CX(I) END DO ELSE * * code for increment not equal to 1 * NINCX = N*INCX DO I = 1,NINCX,INCX CX(I) = CA*CX(I) END DO END IF RETURN END