# File lib/rgl/dot.rb, line 58
58:     def write_to_graphic_file (fmt='png', dotfile="graph")
59:       src = dotfile + ".dot"
60:       dot = dotfile + "." + fmt
61: 
62:       File.open(src, 'w') do |f|
63:         f << self.to_dot_graph.to_s << "\n"
64:       end
65: 
66:       system( "dot -T#{fmt} #{src} -o #{dot}" )
67:       dot
68:     end