LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
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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 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 cdotc(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* .. Intrinsic Functions ..
102 INTRINSIC conjg
103* ..
104 ctemp = (0.0,0.0)
105 cdotc = (0.0,0.0)
106 IF (n.LE.0) RETURN
107 IF (incx.EQ.1 .AND. incy.EQ.1) THEN
108*
109* code for both increments equal to 1
110*
111 DO i = 1,n
112 ctemp = ctemp + conjg(cx(i))*cy(i)
113 END DO
114 ELSE
115*
116* code for unequal increments or equal increments
117* not equal to 1
118*
119 ix = 1
120 iy = 1
121 IF (incx.LT.0) ix = (-n+1)*incx + 1
122 IF (incy.LT.0) iy = (-n+1)*incy + 1
123 DO i = 1,n
124 ctemp = ctemp + conjg(cx(ix))*cy(iy)
125 ix = ix + incx
126 iy = iy + incy
127 END DO
128 END IF
129 cdotc = ctemp
130 RETURN
131*
132* End of CDOTC
133*
134 END
complex function cdotc(N, CX, INCX, CY, INCY)
CDOTC
Definition: cdotc.f:83