Re: Unknown options in Mma 3.0: built-in functions vs. user-defined functions
- To: mathgroup at smc.vnet.net
- Subject: [mg6988] Re: [mg6943] Unknown options in Mma 3.0: built-in functions vs. user-defined functions
- From: David Withoff <withoff>
- Date: Thu, 1 May 1997 14:48:36 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
> Does anyone know why the response to the attempted use of a function > with an unknown option differs depending on whether the function is > built in or user-defined? > > If I try to use, say, Plot, with an unknown option (call it "newopt"), > I get the error message Plot::optx: Unknown option newopt in > Plot[.....]. However, if I use a user-defined function with an > unknown option, I get no error message -- rather, the option is simply > ignored. > > Bob Lawrence This is a reflection of coding conventions and programmer choices rather than a distinction between built-in functions and user-defined functions. The people who write built-in functions (the programmers at Wolfram Research) tend to include tests for unknown options in built-in functions. The same tests can be (and often are) included in user-defined functions too, but not all programmers do that. Dave Withoff Wolfram Research