#
class Statistics
#...
	def draw type, field
		#...
		graph.add type.to_sym, '', table

		graph.render :to => "#{graph_file}.svg"
		#graph.render :width => 300, :height => 200, :to => "#{graph_file}.png", :as => 'png'
	end
end

# the call:
stats.draw(pie, sex)

# Errors Out
# ./statistics.rb:157:in `main': undefined local variable or method `pie' for main:Object (NameError)
#	from ./statistics.rb:162