assemble_resnom_at_each_process Subroutine

    subroutine assemble_resnom_at_each_process(control)
      !< Sum residual obtained from all the processes after MPI_Communication
      implicit none
      type(controltype), intent(in) :: control
      !< Control parameters: number of variables and total mpi processes
      integer :: i,j
      Res_abs=0.
      do i=0,control%total_process-1
        do j = 0,control%n_var
          Res_abs(j) =  Res_abs(j)+buffer((j+1)+(control%n_var+1)*i)
        end do
      end do
      Res_abs(1:) = sqrt(Res_abs(1:))
      Res_abs(0) =  abs(Res_abs(0))
    end subroutine assemble_resnom_at_each_process