ZDOTCI(3)               MathKeisan SPARSE BLAS routine               ZDOTCI(3)



NAME
       ZDOTCI - Complex*16 conjugate indexed dot product

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

           INTEGER        NZ, INDX

           COMPLEX*16     X, Y

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

ARGUMENTS
       ZDOTCI  (output) COMPLEX*16
               Complex*16  function value equal to the conjugated vector inner
               product. If  NZ .le. 0  ZDOTCI 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.


SEE ALSO
       sblas(3)



MathKeisan                         June 1991                         ZDOTCI(3)