keys (SVG::Graph::Pie)

    # File temp/Graph/Pie.rb, line 171
          def keys
            total = 0
            max_value = 0
            @data.each {|x| total += x }
            percent_scale = 100.0 / total
            count = -1
            a = @config[:fields].collect{ |x|
              count += 1
              v = @data[count]
              perc = show_key_percent ? " "+(v * percent_scale).round.to_s+"%" : ""
              x + " [" + v.to_s + "]" + perc
            }
          end