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



NAME
       CDOTUI - Complex indexed dot product

SYNOPSIS
       COMPLEX FUNCTION CDOTUI( NZ, X, INDX, Y )

           INTEGER        NZ, INDX

           COMPLEX        X, Y

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

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

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

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

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

       Y       (input) COMPLEX
               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                      CDOTUI(3)