Re: How do I tell Mathematica than n is an integer?
- To: mathgroup at smc.vnet.net
- Subject: [mg9608] Re: How do I tell Mathematica than n is an integer?
- From: Leszek Sczaniecki <lsczan at concentric.net>
- Date: Fri, 14 Nov 1997 21:39:50 -0500
- Organization: Concentric Internet Services
- Sender: owner-wri-mathgroup at wolfram.com
foo[n_] := OK /; IntegerQ[n] && Positive[n] IntegerQ[n] ^= True;
Positive[n] ^= True;
-leszek
michael a. morrison wrote:
> In writing some packages for courses I'm teaching, I've run into the
> following recurrent difficulty:
>
> How do you tell Mathematica within a notebook session that a variable n
> is a positive integer in such a way that a command defined in a package
> such as
> waveFunction[n_Integer?Positive] := will execute rather than
> returning waveFunction[n] unevaluated. Setting
> Integer[n] ^= True;
> Postive[n] ^= True;
A !
> in the notebook has no effect whatsoever on the failure of Mathematica
> to evaluate waveFunction[n].
>
> I would be very grateful for any advice anyone can give me!
> Thanks---michael morrison (university of oklahoma)
>
> Michael A. Morrison
> Dept. Physics & Astronomy
> University of Oklahoma
> Norman, OK 73019
> Phone: 405 325-3961
> FAX: 405 325-7557