Return to zdscal.f CVS log

Up to [local] / rpl / lapack / blas

Première mise à jour de lapack et blas.

    1: *> \brief \b ZDSCAL
    2: *
    3: *  =========== DOCUMENTATION ===========
    4: *
    5: * Online html documentation available at
    6: *            http://www.netlib.org/lapack/explore-html/
    7: *
    8: *  Definition:
    9: *  ===========
   10: *
   11: *       SUBROUTINE ZDSCAL(N,DA,ZX,INCX)
   12: *
   13: *       .. Scalar Arguments ..
   14: *       DOUBLE PRECISION DA
   15: *       INTEGER INCX,N
   16: *       ..
   17: *       .. Array Arguments ..
   18: *       COMPLEX*16 ZX(*)
   19: *       ..
   20: *
   21: *
   22: *> \par Purpose:
   23: *  =============
   24: *>
   25: *> \verbatim
   26: *>
   27: *>    ZDSCAL scales a vector by a constant.
   28: *> \endverbatim
   29: *
   30: *  Arguments:
   31: *  ==========
   32: *
   33: *> \param[in] N
   34: *> \verbatim
   35: *>          N is INTEGER
   36: *>         number of elements in input vector(s)
   37: *> \endverbatim
   38: *>
   39: *> \param[in] DA
   40: *> \verbatim
   41: *>          DA is DOUBLE PRECISION
   42: *>           On entry, DA specifies the scalar alpha.
   43: *> \endverbatim
   44: *>
   45: *> \param[in,out] ZX
   46: *> \verbatim
   47: *>          ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
   48: *> \endverbatim
   49: *>
   50: *> \param[in] INCX
   51: *> \verbatim
   52: *>          INCX is INTEGER
   53: *>         storage spacing between elements of ZX
   54: *> \endverbatim
   55: *
   56: *  Authors:
   57: *  ========
   58: *
   59: *> \author Univ. of Tennessee
   60: *> \author Univ. of California Berkeley
   61: *> \author Univ. of Colorado Denver
   62: *> \author NAG Ltd.
   63: *
   64: *> \ingroup complex16_blas_level1
   65: *
   66: *> \par Further Details:
   67: *  =====================
   68: *>
   69: *> \verbatim
   70: *>
   71: *>     jack dongarra, 3/11/78.
   72: *>     modified 3/93 to return if incx .le. 0.
   73: *>     modified 12/3/93, array(1) declarations changed to array(*)
   74: *> \endverbatim
   75: *>
   76: *  =====================================================================
   77:       SUBROUTINE ZDSCAL(N,DA,ZX,INCX)
   78: *
   79: *  -- Reference BLAS level1 routine --
   80: *  -- Reference BLAS is a software package provided by Univ. of Tennessee,    --
   81: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
   82: *
   83: *     .. Scalar Arguments ..
   84:       DOUBLE PRECISION DA
   85:       INTEGER INCX,N
   86: *     ..
   87: *     .. Array Arguments ..
   88:       COMPLEX*16 ZX(*)
   89: *     ..
   90: *
   91: *  =====================================================================
   92: *
   93: *     .. Local Scalars ..
   94:       INTEGER I,NINCX
   95: *     .. Parameters ..
   96:       DOUBLE PRECISION ONE
   97:       PARAMETER (ONE=1.0D+0)
   98: *     ..
   99: *     .. Intrinsic Functions ..
  100:       INTRINSIC DBLE, DCMPLX, DIMAG
  101: *     ..
  102:       IF (N.LE.0 .OR. INCX.LE.0 .OR. DA.EQ.ONE) RETURN
  103:       IF (INCX.EQ.1) THEN
  104: *
  105: *        code for increment equal to 1
  106: *
  107:          DO I = 1,N
  108:             ZX(I) = DCMPLX(DA*DBLE(ZX(I)),DA*DIMAG(ZX(I)))
  109:          END DO
  110:       ELSE
  111: *
  112: *        code for increment not equal to 1
  113: *
  114:          NINCX = N*INCX
  115:          DO I = 1,NINCX,INCX
  116:             ZX(I) = DCMPLX(DA*DBLE(ZX(I)),DA*DIMAG(ZX(I)))
  117:          END DO
  118:       END IF
  119:       RETURN
  120: *
  121: *     End of ZDSCAL
  122: *
  123:       END