c
c  Workers receive X, then compute dot products until 
c  done message received
c
      else

        call MPI_BCAST ( x, cols, MPI_DOUBLE_PRECISION, master, 
     &    MPI_COMM_WORLD, ierr )

 90     continue

        call MPI_RECV ( buffer, cols, MPI_DOUBLE_PRECISION, master, 
     &    MPI_ANY_TAG, MPI_COMM_WORLD, status, ierr )

        if ( status(MPI_TAG) .eq. 0 ) then
          go to 200
        end if

        row = status(MPI_TAG)

        ans = 0.0
        do i = 1, cols
          ans = ans + buffer(i) * x(i)
        end do

        call MPI_SEND ( ans, 1, MPI_DOUBLE_PRECISION, master, 
     &     row, MPI_COMM_WORLD, ierr )

        go to 90

 200    continue

      end if