LAPACK  3.10.0
LAPACK: Linear Algebra PACKage

◆ cdotc()

complex function cdotc ( integer  N,
complex, dimension(*)  CX,
integer  INCX,
complex, dimension(*)  CY,
integer  INCY 
)

CDOTC

Purpose:
 CDOTC forms the dot product of two complex vectors
      CDOTC = X^H * Y
Parameters
[in]N
          N is INTEGER
         number of elements in input vector(s)
[in]CX
          CX is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]INCX
          INCX is INTEGER
         storage spacing between elements of CX
[in]CY
          CY is COMPLEX array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
[in]INCY
          INCY is INTEGER
         storage spacing between elements of CY
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Further Details:
     jack dongarra, linpack,  3/11/78.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 82 of file cdotc.f.

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 *
complex function cdotc(N, CX, INCX, CY, INCY)
CDOTC
Definition: cdotc.f:83
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