LAPACK  3.5.0
LAPACK: Linear Algebra PACKage
cdotc.f File Reference

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Functions/Subroutines

complex function cdotc (N, CX, INCX, CY, INCY)
 CDOTC More...
 

Function/Subroutine Documentation

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

CDOTC

Purpose:
    forms the dot product of two vectors, conjugating the first
    vector.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
November 2011
Further Details:
     jack dongarra, linpack,  3/11/78.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 53 of file cdotc.f.

53 *
54 * -- Reference BLAS level1 routine (version 3.4.0) --
55 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
56 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
57 * November 2011
58 *
59 * .. Scalar Arguments ..
60  INTEGER incx,incy,n
61 * ..
62 * .. Array Arguments ..
63  COMPLEX cx(*),cy(*)
64 * ..
65 *
66 * =====================================================================
67 *
68 * .. Local Scalars ..
69  COMPLEX ctemp
70  INTEGER i,ix,iy
71 * ..
72 * .. Intrinsic Functions ..
73  INTRINSIC conjg
74 * ..
75  ctemp = (0.0,0.0)
76  cdotc = (0.0,0.0)
77  IF (n.LE.0) RETURN
78  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
79 *
80 * code for both increments equal to 1
81 *
82  DO i = 1,n
83  ctemp = ctemp + conjg(cx(i))*cy(i)
84  END DO
85  ELSE
86 *
87 * code for unequal increments or equal increments
88 * not equal to 1
89 *
90  ix = 1
91  iy = 1
92  IF (incx.LT.0) ix = (-n+1)*incx + 1
93  IF (incy.LT.0) iy = (-n+1)*incy + 1
94  DO i = 1,n
95  ctemp = ctemp + conjg(cx(ix))*cy(iy)
96  ix = ix + incx
97  iy = iy + incy
98  END DO
99  END IF
100  cdotc = ctemp
101  RETURN
complex function cdotc(N, CX, INCX, CY, INCY)
CDOTC
Definition: cdotc.f:53