# File temp/Graph/Graph.rb, line 442
      def calculate_bottom_margin
        @border_bottom = 7
        if key and key_position == :bottom
          @border_bottom += @data.size * (font_size + 5)
          @border_bottom += 10
        end
        if show_x_labels
                  max_x_label_height_px = (not rotate_x_labels) ? 
            x_label_font_size :
            get_x_labels.max{|a,b| 
              a.to_s.length<=>b.to_s.length
            }.to_s.length * x_label_font_size * 0.6
          @border_bottom += max_x_label_height_px
          @border_bottom += max_x_label_height_px + 10 if stagger_x_labels
        end
        @border_bottom += x_title_font_size + 5 if show_x_title
      end