LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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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