get_field_weighted_average_kperp2 Function

  function get_field_weighted_average_kperp2(field) result(average)
    use kt_grids, only: kperp2, naky, ntheta0
    use theta_grid, only: ntgrid, field_line_average
    implicit none
    complex, dimension(-ntgrid:ntgrid, ntheta0, naky), intent(in) :: field
    real, dimension(ntheta0, naky) :: average
    real, dimension(-ntgrid:ntgrid, ntheta0, naky) :: field_squared
    integer :: it, ik
    field_squared = abs(field) * abs(field)
    average = 0.0
    do ik = 1, naky
       do it = 1, ntheta0
          if (maxval(abs(field_squared(:, it, ik))) <= epsilon(0.0)) cycle
          average(it, ik) = field_line_average(field_squared(:, it, ik) * &
               kperp2(:, it, ik)) / field_line_average(field_squared(:, it, ik))
       end do
    end do
  end function get_field_weighted_average_kperp2