version 1.1.1.1, 2010/01/26 15:22:45
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version 1.16, 2023/08/07 08:38:44
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*> \brief \b ZDSCAL |
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* |
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* =========== DOCUMENTATION =========== |
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* |
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* Online html documentation available at |
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* http://www.netlib.org/lapack/explore-html/ |
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* |
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* Definition: |
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* =========== |
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* |
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* SUBROUTINE ZDSCAL(N,DA,ZX,INCX) |
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* |
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* .. Scalar Arguments .. |
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* DOUBLE PRECISION DA |
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* INTEGER INCX,N |
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* .. |
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* .. Array Arguments .. |
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* COMPLEX*16 ZX(*) |
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* .. |
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* |
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* |
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*> \par Purpose: |
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* ============= |
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*> |
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*> \verbatim |
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*> |
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*> ZDSCAL scales a vector by a constant. |
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*> \endverbatim |
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* |
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* Arguments: |
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* ========== |
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* |
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*> \param[in] N |
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*> \verbatim |
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*> N is INTEGER |
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*> number of elements in input vector(s) |
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*> \endverbatim |
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*> |
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*> \param[in] DA |
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*> \verbatim |
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*> DA is DOUBLE PRECISION |
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*> On entry, DA specifies the scalar alpha. |
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*> \endverbatim |
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*> |
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*> \param[in,out] ZX |
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*> \verbatim |
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*> ZX is COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) ) |
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*> \endverbatim |
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*> |
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*> \param[in] INCX |
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*> \verbatim |
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*> INCX is INTEGER |
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*> storage spacing between elements of ZX |
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*> \endverbatim |
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* |
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* Authors: |
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* ======== |
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* |
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*> \author Univ. of Tennessee |
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*> \author Univ. of California Berkeley |
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*> \author Univ. of Colorado Denver |
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*> \author NAG Ltd. |
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* |
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*> \ingroup complex16_blas_level1 |
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* |
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*> \par Further Details: |
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* ===================== |
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*> |
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*> \verbatim |
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*> |
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*> jack dongarra, 3/11/78. |
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*> modified 3/93 to return if incx .le. 0. |
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*> modified 12/3/93, array(1) declarations changed to array(*) |
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*> \endverbatim |
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*> |
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* ===================================================================== |
SUBROUTINE ZDSCAL(N,DA,ZX,INCX) |
SUBROUTINE ZDSCAL(N,DA,ZX,INCX) |
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* |
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* -- Reference BLAS level1 routine -- |
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* -- Reference BLAS is a software package provided by Univ. of Tennessee, -- |
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* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
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* |
* .. Scalar Arguments .. |
* .. Scalar Arguments .. |
DOUBLE PRECISION DA |
DOUBLE PRECISION DA |
INTEGER INCX,N |
INTEGER INCX,N |
* .. |
* .. |
* .. Array Arguments .. |
* .. Array Arguments .. |
DOUBLE COMPLEX ZX(*) |
COMPLEX*16 ZX(*) |
* .. |
* .. |
* |
* |
* Purpose |
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* ======= |
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* |
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* ZDSCAL scales a vector by a constant. |
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* |
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* Further Details |
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* =============== |
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* |
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* jack dongarra, 3/11/78. |
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* modified 3/93 to return if incx .le. 0. |
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* modified 12/3/93, array(1) declarations changed to array(*) |
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* |
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* ===================================================================== |
* ===================================================================== |
* |
* |
* .. Local Scalars .. |
* .. Local Scalars .. |
INTEGER I,IX |
INTEGER I,NINCX |
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* .. Parameters .. |
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DOUBLE PRECISION ONE |
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PARAMETER (ONE=1.0D+0) |
* .. |
* .. |
* .. Intrinsic Functions .. |
* .. Intrinsic Functions .. |
INTRINSIC DCMPLX |
INTRINSIC DBLE, DCMPLX, DIMAG |
* .. |
* .. |
IF (N.LE.0 .OR. INCX.LE.0) RETURN |
IF (N.LE.0 .OR. INCX.LE.0 .OR. DA.EQ.ONE) RETURN |
IF (INCX.EQ.1) GO TO 20 |
IF (INCX.EQ.1) THEN |
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* |
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* code for increment equal to 1 |
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* |
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DO I = 1,N |
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ZX(I) = DCMPLX(DA*DBLE(ZX(I)),DA*DIMAG(ZX(I))) |
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END DO |
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ELSE |
* |
* |
* code for increment not equal to 1 |
* code for increment not equal to 1 |
* |
* |
IX = 1 |
NINCX = N*INCX |
DO 10 I = 1,N |
DO I = 1,NINCX,INCX |
ZX(IX) = DCMPLX(DA,0.0d0)*ZX(IX) |
ZX(I) = DCMPLX(DA*DBLE(ZX(I)),DA*DIMAG(ZX(I))) |
IX = IX + INCX |
END DO |
10 CONTINUE |
END IF |
RETURN |
RETURN |
* |
* |
* code for increment equal to 1 |
* End of ZDSCAL |
* |
* |
20 DO 30 I = 1,N |
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ZX(I) = DCMPLX(DA,0.0d0)*ZX(I) |
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30 CONTINUE |
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RETURN |
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END |
END |