Annotation of rpl/lapack/blas/zscal.f, revision 1.16
1.8 bertrand 1: *> \brief \b ZSCAL
2: *
3: * =========== DOCUMENTATION ===========
4: *
1.13 bertrand 5: * Online html documentation available at
6: * http://www.netlib.org/lapack/explore-html/
1.8 bertrand 7: *
8: * Definition:
9: * ===========
10: *
11: * SUBROUTINE ZSCAL(N,ZA,ZX,INCX)
1.13 bertrand 12: *
1.8 bertrand 13: * .. Scalar Arguments ..
14: * COMPLEX*16 ZA
15: * INTEGER INCX,N
16: * ..
17: * .. Array Arguments ..
18: * COMPLEX*16 ZX(*)
19: * ..
1.13 bertrand 20: *
1.8 bertrand 21: *
22: *> \par Purpose:
23: * =============
24: *>
25: *> \verbatim
26: *>
27: *> ZSCAL scales a vector by a constant.
28: *> \endverbatim
29: *
1.14 bertrand 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] ZA
40: *> \verbatim
41: *> ZA is COMPLEX*16
42: *> On entry, ZA 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: *
1.8 bertrand 56: * Authors:
57: * ========
58: *
1.13 bertrand 59: *> \author Univ. of Tennessee
60: *> \author Univ. of California Berkeley
61: *> \author Univ. of Colorado Denver
62: *> \author NAG Ltd.
1.8 bertrand 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: * =====================================================================
1.1 bertrand 77: SUBROUTINE ZSCAL(N,ZA,ZX,INCX)
1.8 bertrand 78: *
1.16 ! bertrand 79: * -- Reference BLAS level1 routine --
1.8 bertrand 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: *
1.1 bertrand 83: * .. Scalar Arguments ..
1.8 bertrand 84: COMPLEX*16 ZA
1.1 bertrand 85: INTEGER INCX,N
86: * ..
87: * .. Array Arguments ..
1.8 bertrand 88: COMPLEX*16 ZX(*)
1.1 bertrand 89: * ..
90: *
91: * =====================================================================
92: *
93: * .. Local Scalars ..
1.7 bertrand 94: INTEGER I,NINCX
1.1 bertrand 95: * ..
1.16 ! bertrand 96: * .. Parameters ..
! 97: COMPLEX*16 ONE
! 98: PARAMETER (ONE= (1.0D+0,0.0D+0))
! 99: * ..
! 100: IF (N.LE.0 .OR. INCX.LE.0 .OR. ZA.EQ.ONE) RETURN
1.7 bertrand 101: IF (INCX.EQ.1) THEN
1.1 bertrand 102: *
1.7 bertrand 103: * code for increment equal to 1
1.1 bertrand 104: *
1.7 bertrand 105: DO I = 1,N
106: ZX(I) = ZA*ZX(I)
107: END DO
108: ELSE
1.1 bertrand 109: *
1.7 bertrand 110: * code for increment not equal to 1
1.1 bertrand 111: *
1.7 bertrand 112: NINCX = N*INCX
113: DO I = 1,NINCX,INCX
114: ZX(I) = ZA*ZX(I)
115: END DO
116: END IF
1.1 bertrand 117: RETURN
1.16 ! bertrand 118: *
! 119: * End of ZSCAL
! 120: *
1.1 bertrand 121: END
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