ZDOTUI(3)    SPARSE BLAS routine of NEC Numeric Library Collection   ZDOTUI(3)



NAME
       ZDOTUI - Complex*16 indexed dot product

SYNOPSIS
       COMPLEX*16 FUNCTION ZDOTUI( NZ, X, INDX, Y )

           INTEGER        NZ, INDX

           COMPLEX*16     X, Y

PURPOSE
       ZDOTUI  computes the vector inner product of a complex*16 sparse vector
       X stored in compressed form  ( X, INDX ) with a  complex*16  vector   Y
       in  full  storage form. Only the elements of Y whose indices are listed
       in INDX are referenced.
       ZDOTUI computes:
                                 NZ
          ZDOTUI  <--  X * Y  =  Sum  X(i) * Y( INDX(i) )
                                 i=1
       where X and Y are complex*16 vectors.

ARGUMENTS
       ZDOTUI  (output) COMPLEX*16
               Complex*16 function value equal to the vector inner product. If
               NZ .le. 0  ZDOTUI is set to zero.

       NZ      (input) INTEGER
               Number of elements in the compressed form.

       X       (input) COMPLEX*16
               Array containing the values of the compressed form.

       INDX    (input) INTEGER
               Array containing the indices of the compressed form.

       Y       (input) COMPLEX*16
               Array,  on  input,  which contains the vector Y in full storage
               form. Only the elements corresponding to the  indices  in  INDX
               will be accessed.

FURTHER DETAILS
       Sparse  BLAS  algorithm  is  from  ACM  algorithm  692 by D. Dodson, R.
       Grimes, and J. Lewis.




SPARSE BLAS routine             31 October 2017                      ZDOTUI(3)