hypre_obj_Init Subroutine

    impure subroutine hypre_obj_Init(this,block,parallel)
      !> Initializes the hypre object.
      implicit none
      class(hypre_obj),   intent(inout) :: this                                !! Hypre machinery
      type(block_obj),    intent(in),    &
                                 target :: block                               !! A block object
      type(parallel_obj), intent(in),    &
                                 target :: parallel                            !! Parallel structure to link with
      ! Work variables
      integer :: ierr

      ! Point to the master objects
      this%parallel => parallel
      this%block    => block

      ! Scaling factor
      this%h2 = minval(this%block%dx)**2

      ! Set internal MPI communicator
      this%comm = this%parallel%comm%g

      ! Initialize Hypre internals
      call HYPRE_Init(ierr)

      return
    end subroutine hypre_obj_Init