# File Geodesic_SketchUp.rb, line 119
        def self.create( frequency = nil, primitive = :octahedron, radius = 36 )
                if !frequency
                        prompts = [ 'Primitive:', 'Radius (in "):', 'Subdivisions:' ]
                        values = [ primitive.to_s, radius, 2 ]
                        primitive_types = ['tetrahedron|octahedron|icosahedron']
                        results = inputbox prompts, values, primitive_types, 'Create Geodesic'
                        return unless results
                        primitive, radius, frequency = results
                        primitive = primitive.to_sym
                end

                raise "The Geodesic class does not support the primitive type '#{primitive}'" unless PRIMITIVES[primitive]

                model = Sketchup.active_model
                model.start_operation "Create Geodesic"
                group = model.active_entities.add_group

                PRIMITIVES[primitive].each{ |face|
                        self.expand_face( face, frequency.to_i, radius.to_f, group.entities )
                }

            model.commit_operation
            group
        end