Re: arguments/realtime3d
- To: mathgroup at smc.vnet.net
- Subject: [mg32286] Re: [mg32246] arguments/realtime3d
- From: "P.J. Hinton" <paulh at wolfram.com>
- Date: Fri, 11 Jan 2002 04:35:20 -0500 (EST)
- Organization: "Wolfram Research, Inc."
- Sender: owner-wri-mathgroup at wolfram.com
On Wed, 9 Jan 2002, daniel wrote:
> Is there a way to obtain the number of arguments with wich
> the function was called as in
> f[x___?OptionQ]:=Module ...?
In principle, it should be possible to invoke Length[] on a list wrapped
around the argument sequence.
In[1]:= g[x___?OptionQ] := Print["Number of arguments: ", Length[{x}]]
In[2]:= g[a -> b, c -> d, e -> f]
Number of arguments: 3
Why would one create a function with only optional arguments in the first
place? Do you intend a Null argument to be valid input as well?
> I would like to check if x contains only valid options of f (defined with
> Options[f,a->1])
See the function FilterOptions[], which is defined in the Standard Package
Utilities`FilterOptions`. For more information, paste the following
expression in a notebook and evaluate it.
FrontEndExecute[
FrontEnd`HelpBrowserLookup["AddOns", "Utilities`FilterOptions`"]
]
> second question: is there a way to have RealTime3D under Linux (Matematica
> 4.0)
No, RealTime3D wasn't introduced on X Window front ends until the release
of Mathematica 4.1.
--
P.J. Hinton
User Interface Programmer paulh at wolfram.com
Wolfram Research, Inc.
Disclaimer: Opinions expressed herein are those of the author alone.