calc_jext Subroutine

  subroutine calc_jext (istep, j_ext)
    use mp, only: proc0
    use antenna, only: get_jext
    implicit none
    !> Current simulation timestep
    integer, intent (in) :: istep
    !Shouldn't really need intent in here but it's beacuse we zero it before calling calc_jext
    real, dimension(:,:), intent(in out) ::  j_ext

    integer :: i

    call get_jext(j_ext)

    !Do averages with a history variable
    if (proc0) then
       !Save variable to history
       if (navg > 1) then
          ! This looks a little odd as we ignore the first step
          if (istep > 1) &
               j_ext_hist(:,:,mod(istep,navg))= j_ext(:,:)

          !Use average of history
          if (istep >= navg) then
             j_ext=0.
             do i=0,navg-1
                j_ext(:,:) = j_ext(:,:) + j_ext_hist(:,:,i)/ real(navg)
             end do
          end if
       end if
    end if

  end subroutine calc_jext