LAPACK  3.10.0
LAPACK: Linear Algebra PACKage
cdotu.f
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1 *> \brief \b CDOTU
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 CDOTU(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 *> CDOTU forms the dot product of two complex vectors
27 *> CDOTU = X^T * 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 COMPLEX 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 COMPLEX 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 *> \ingroup complex_blas_level1
71 *
72 *> \par Further Details:
73 * =====================
74 *>
75 *> \verbatim
76 *>
77 *> jack dongarra, linpack, 3/11/78.
78 *> modified 12/3/93, array(1) declarations changed to array(*)
79 *> \endverbatim
80 *>
81 * =====================================================================
82  COMPLEX FUNCTION cdotu(N,CX,INCX,CY,INCY)
83 *
84 * -- Reference BLAS level1 routine --
85 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
86 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
87 *
88 * .. Scalar Arguments ..
89  INTEGER incx,incy,n
90 * ..
91 * .. Array Arguments ..
92  COMPLEX cx(*),cy(*)
93 * ..
94 *
95 * =====================================================================
96 *
97 * .. Local Scalars ..
98  COMPLEX ctemp
99  INTEGER i,ix,iy
100 * ..
101  ctemp = (0.0,0.0)
102  cdotu = (0.0,0.0)
103  IF (n.LE.0) RETURN
104  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
105 *
106 * code for both increments equal to 1
107 *
108  DO i = 1,n
109  ctemp = ctemp + cx(i)*cy(i)
110  END DO
111  ELSE
112 *
113 * code for unequal increments or equal increments
114 * not equal to 1
115 *
116  ix = 1
117  iy = 1
118  IF (incx.LT.0) ix = (-n+1)*incx + 1
119  IF (incy.LT.0) iy = (-n+1)*incy + 1
120  DO i = 1,n
121  ctemp = ctemp + cx(ix)*cy(iy)
122  ix = ix + incx
123  iy = iy + incy
124  END DO
125  END IF
126  cdotu = ctemp
127  RETURN
128 *
129 * End of CDOTU
130 *
131  END
complex function cdotu(N, CX, INCX, CY, INCY)
CDOTU
Definition: cdotu.f:83