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

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Functions/Subroutines

complex function cdotu (N, CX, INCX, CY, INCY)
 CDOTU More...
 

Function/Subroutine Documentation

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

CDOTU

Purpose:
    CDOTU forms the dot product of two vectors.
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 52 of file cdotu.f.

52 *
53 * -- Reference BLAS level1 routine (version 3.4.0) --
54 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
55 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
56 * November 2011
57 *
58 * .. Scalar Arguments ..
59  INTEGER incx,incy,n
60 * ..
61 * .. Array Arguments ..
62  COMPLEX cx(*),cy(*)
63 * ..
64 *
65 * =====================================================================
66 *
67 * .. Local Scalars ..
68  COMPLEX ctemp
69  INTEGER i,ix,iy
70 * ..
71  ctemp = (0.0,0.0)
72  cdotu = (0.0,0.0)
73  IF (n.LE.0) RETURN
74  IF (incx.EQ.1 .AND. incy.EQ.1) THEN
75 *
76 * code for both increments equal to 1
77 *
78  DO i = 1,n
79  ctemp = ctemp + cx(i)*cy(i)
80  END DO
81  ELSE
82 *
83 * code for unequal increments or equal increments
84 * not equal to 1
85 *
86  ix = 1
87  iy = 1
88  IF (incx.LT.0) ix = (-n+1)*incx + 1
89  IF (incy.LT.0) iy = (-n+1)*incy + 1
90  DO i = 1,n
91  ctemp = ctemp + cx(ix)*cy(iy)
92  ix = ix + incx
93  iy = iy + incy
94  END DO
95  END IF
96  cdotu = ctemp
97  RETURN
complex function cdotu(N, CX, INCX, CY, INCY)
CDOTU
Definition: cdotu.f:52