LAPACK  3.8.0
LAPACK: Linear Algebra PACKage

◆ zdotu()

complex*16 function zdotu ( integer  N,
complex*16, dimension(*)  ZX,
integer  INCX,
complex*16, dimension(*)  ZY,
integer  INCY 
)

ZDOTU

Purpose:
 ZDOTU forms the dot product of two complex vectors
      ZDOTU = X^T * Y
Parameters
[in]N
          N is INTEGER
         number of elements in input vector(s)
[in]ZX
          ZX is REAL array, dimension ( 1 + ( N - 1 )*abs( INCX ) )
[in]INCX
          INCX is INTEGER
         storage spacing between elements of ZX
[in]ZY
          ZY is REAL array, dimension ( 1 + ( N - 1 )*abs( INCY ) )
[in]INCY
          INCY is INTEGER
         storage spacing between elements of ZY
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
November 2017
Further Details:
     jack dongarra, 3/11/78.
     modified 12/3/93, array(1) declarations changed to array(*)

Definition at line 85 of file zdotu.f.

85 *
86 * -- Reference BLAS level1 routine (version 3.8.0) --
87 * -- Reference BLAS is a software package provided by Univ. of Tennessee, --
88 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
89 * November 2017
90 *
91 * .. Scalar Arguments ..
92  INTEGER incx,incy,n
93 * ..
94 * .. Array Arguments ..
95  COMPLEX*16 zx(*),zy(*)
96 * ..
97 *
98 * =====================================================================
99 *
100 * .. Local Scalars ..
101  COMPLEX*16 ztemp
102  INTEGER i,ix,iy
103 * ..
104  ztemp = (0.0d0,0.0d0)
105  zdotu = (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 + 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 + zx(ix)*zy(iy)
125  ix = ix + incx
126  iy = iy + incy
127  END DO
128  END IF
129  zdotu = ztemp
130  RETURN
complex *16 function zdotu(N, ZX, INCX, ZY, INCY)
ZDOTU
Definition: zdotu.f:85
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