# File temp/Graph/Plot.rb, line 240 def field_height values = get_y_values max = @data.collect{|x| x[:data][Y].max }.max if values.length == 1 dx = values[-1] else dx = (max - values[-1]).to_f / (values[-1] - values[-2]) end (@graph_height.to_f - font_size*2*top_font) / (values.length + dx - top_align) end