LAPACK 3.11.0 LAPACK: Linear Algebra PACKage
Searching...
No Matches
zdotc.f
Go to the documentation of this file.
1*> \brief \b ZDOTC
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*16 FUNCTION ZDOTC(N,ZX,INCX,ZY,INCY)
12*
13* .. Scalar Arguments ..
14* INTEGER INCX,INCY,N
15* ..
16* .. Array Arguments ..
17* COMPLEX*16 ZX(*),ZY(*)
18* ..
19*
20*
21*> \par Purpose:
22* =============
23*>
24*> \verbatim
25*>
26*> ZDOTC forms the dot product of two complex vectors
27*> ZDOTC = 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] ZX
41*> \verbatim
42*> ZX is COMPLEX*16 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 ZX
49*> \endverbatim
50*>
51*> \param[in] ZY
52*> \verbatim
53*> ZY is COMPLEX*16 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 ZY
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 complex16_blas_level1
71*
72*> \par Further Details:
73* =====================
74*>
75*> \verbatim
76*>
77*> jack dongarra, 3/11/78.
78*> modified 12/3/93, array(1) declarations changed to array(*)
79*> \endverbatim
80*>
81* =====================================================================
82 COMPLEX*16 FUNCTION zdotc(N,ZX,INCX,ZY,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*16 zx(*),zy(*)
93* ..
94*
95* =====================================================================
96*
97* .. Local Scalars ..
98 COMPLEX*16 ztemp
99 INTEGER i,ix,iy
100* ..
101* .. Intrinsic Functions ..
102 INTRINSIC dconjg
103* ..
104 ztemp = (0.0d0,0.0d0)
105 zdotc = (0.0d0,0.0d0)
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 ztemp = ztemp + dconjg(zx(i))*zy(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 ztemp = ztemp + dconjg(zx(ix))*zy(iy)
125 ix = ix + incx
126 iy = iy + incy
127 END DO
128 END IF
129 zdotc = ztemp
130 RETURN
131*
132* End of ZDOTC
133*
134 END
complex *16 function zdotc(N, ZX, INCX, ZY, INCY)
ZDOTC
Definition: zdotc.f:83