gistfile1.rb

  # Calculate the intake fraction where iF = SUM(popDensN * DispN)
  # where popDensN is the population density in an N meter buffer minus the previous buffer
  def intake_fraction
    fraction = 0
    inner_pop = 0
    inner_area = 0
    DISPERSION_FACTORS.each do |buffer, value|
      pop_in_buffer = send("pop#{buffer}m").to_i
      area_in_buffer = send("area#{buffer}m").to_i

      fraction += value * (pop_in_buffer - inner_pop) / (area_in_buffer - inner_area)

      # Save the population and area from this buffer to subtract from the next
      inner_pop = pop_in_buffer
      inner_area = area_in_buffer
    end

    return fraction
  end