LAPACK  3.7.1
LAPACK: Linear Algebra PACKage
cdotc.f
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1 *> \brief \b CDOTC
2 *
3 * =========== DOCUMENTATION ===========
4 *
5 * Online html documentation available at
6 * http://www.netlib.org/lapack/explore-html/
7 *
8 * Definition:
9 * ===========
10 *
11 * COMPLEX FUNCTION CDOTC(N,CX,INCX,CY,INCY)
12 *
13 * .. Scalar Arguments ..
14 * INTEGER INCX,INCY,N
15 * ..
16 * .. Array Arguments ..
17 * COMPLEX CX(*),CY(*)
18 * ..
19 *
20 *
21 *> \par Purpose:
22 * =============
23 *>
24 *> \verbatim
25 *>
26 *> CDOTC forms the dot product of two complex vectors
27 *> CDOTC = X^H * Y
28 *>
29 *> \endverbatim
30 *
31 * Arguments:
32 * ==========
33 *
34 *> \param[in] N
35 *> \verbatim
36 *> N is INTEGER
37 *> number of elements in input vector(s)
38 *> \endverbatim
39 *>
40 *> \param[in] CX
41 *> \verbatim
42 *> CX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
43 *> \endverbatim
44 *>
45 *> \param[in] INCX
46 *> \verbatim
47 *> INCX is INTEGER
48 *> storage spacing between elements of CX
49 *> \endverbatim
50 *>
51 *> \param[in] CY
52 *> \verbatim
53 *> CY is REAL array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
54 *> \endverbatim
55 *>
56 *> \param[in] INCY
57 *> \verbatim
58 *> INCY is INTEGER
59 *> storage spacing between elements of CY
60 *> \endverbatim
61 *
62 * Authors:
63 * ========
64 *
65 *> \author Univ. of Tennessee
66 *> \author Univ. of California Berkeley
67 *> \author Univ. of Colorado Denver
68 *> \author NAG Ltd.
69 *
70 *> \date December 2016
71 *
72 *> \ingroup complex_blas_level1
73 *
74 *> \par Further Details:
75 * =====================
76 *>
77 *> \verbatim
78 *>
79 *> jack dongarra, linpack, 3/11/78.
80 *> modified 12/3/93, array(1) declarations changed to array(*)
81 *> \endverbatim
82 *>
83 * =====================================================================
84  COMPLEX FUNCTION cdotc(N,CX,INCX,CY,INCY)
85 *
86 * -- Reference BLAS level1 routine (version 3.7.0) --
87 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
88 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
89 * December 2016
90 *
91 * .. Scalar Arguments ..
92  INTEGER INCX,INCY,N
93 * ..
94 * .. Array Arguments ..
95  COMPLEX CX(*),CY(*)
96 * ..
97 *
98 * =====================================================================
99 *
100 * .. Local Scalars ..
101  COMPLEX CTEMP
102  INTEGER I,IX,IY
103 * ..
104 * .. Intrinsic Functions ..
105  INTRINSIC conjg
106 * ..
107  ctemp = (0.0,0.0)
108  cdotc = (0.0,0.0)
109  IF (n.LE.0) RETURN
110  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
111 *
112 * code for both increments equal to 1
113 *
114  DO i = 1,n
115  ctemp = ctemp + conjg(cx(i))*cy(i)
116  END DO
117  ELSE
118 *
119 * code for unequal increments or equal increments
120 * not equal to 1
121 *
122  ix = 1
123  iy = 1
124  IF (incx.LT.0) ix = (-n+1)*incx + 1
125  IF (incy.LT.0) iy = (-n+1)*incy + 1
126  DO i = 1,n
127  ctemp = ctemp + conjg(cx(ix))*cy(iy)
128  ix = ix + incx
129  iy = iy + incy
130  END DO
131  END IF
132  cdotc = ctemp
133  RETURN
134  END
complex function cdotc(N, CX, INCX, CY, INCY)
CDOTC
Definition: cdotc.f:85