LAPACK: BLAS/SRC/zdscal.f Source File

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00001       SUBROUTINE ZDSCAL(N,DA,ZX,INCX)
00002 *     .. Scalar Arguments ..
00003       DOUBLE PRECISION DA
00004       INTEGER INCX,N
00005 *     ..
00006 *     .. Array Arguments ..
00007       DOUBLE COMPLEX ZX(*)
00008 *     ..
00009 *
00010 *  Purpose
00011 *  =======
00012 *
00013 *     ZDSCAL scales a vector by a constant.
00014 *
00015 *  Further Details
00016 *  ===============
00017 *
00018 *     jack dongarra, 3/11/78.
00019 *     modified 3/93 to return if incx .le. 0.
00020 *     modified 12/3/93, array(1) declarations changed to array(*)
00021 *
00022 *  =====================================================================
00023 *
00024 *     .. Local Scalars ..
00025       INTEGER I,IX
00026 *     ..
00027 *     .. Intrinsic Functions ..
00028       INTRINSIC DCMPLX
00029 *     ..
00030       IF (N.LE.0 .OR. INCX.LE.0) RETURN
00031       IF (INCX.EQ.1) GO TO 20
00032 *
00033 *        code for increment not equal to 1
00034 *
00035       IX = 1
00036       DO 10 I = 1,N
00037           ZX(IX) = DCMPLX(DA,0.0d0)*ZX(IX)
00038           IX = IX + INCX
00039    10 CONTINUE
00040       RETURN
00041 *
00042 *        code for increment equal to 1
00043 *
00044    20 DO 30 I = 1,N
00045           ZX(I) = DCMPLX(DA,0.0d0)*ZX(I)
00046    30 CONTINUE
00047       RETURN
00048       END