Hi Rich, Thanks a lot for the very good idea. I just have to weigh, which interface will be more natural for the people in engineering. (Probably I should conduct a survey myself? But well, probably when there is a GUI, this difference will not matter much.) Let me guess, because unlike Python, Ruby does not have named parameters in method calls, this is a kind of a standard way to emulate them, isn't it? Regards, Bill =========================================================================== Rich Kilmer <rich / infoether.com> wrote: > usage: > link(n1, n2, :name=>'wiggy', :simEnd=>true)