How to write a function which may return noun form of itself in Maxima language
Subject: How to write a function which may return noun form of itself in Maxima language
From: Stavros Macrakis
Date: Sat, 6 Aug 2011 15:07:14 -0400
I suggest you use the "simplifying" package for things like this. Please
see:
* http://www.ma.utexas.edu/pipermail/maxima/2007/006397.html
* http://permalink.gmane.org/gmane.comp.mathematics.maxima.general/34008
for a quick introduction.
-s
2011/8/6 ???? <yasuaki.honda at gmail.com>
> Dear maxima users,
>
> Is there a suggested way to write a function in Maxima language which
> may return its noun form if it cannot process the arguments?
>
> Let me explain the issue with the following example:
> The (%i27) defines a function which returns its noun form if the argument
> is
> not a number.
> (%i27) f(x):=if numberp(x) then x^2 else 'f(x)$
>
> (%i28) f(n+3);
> (%o28) 'f(n+3)
> So far it seems working as defined.
>
> (%i29) %,n:5;
> (%o29) 'f(8)
>
> (%i30) %,nouns;
> (%o30) 64
> With additional informations, I can continue to compute using nouns flag.
> All this seems good. However:
>
> (%i31) f(n+3);
> (%o31) 'f(n+3)
>
> (%i32) %,nouns;
>
> This rather simpler example at (%i32), it never returns. It looks like the
> infinite recursive loop happens.
>
> I noticed that if everything is written in Lisp, then the above infinite
> loop
> can be avoided. integrate() and sum() functions does not cause such
> loop when evaluated with nouns.
>
> So my question is, is there any suggested way to write a function that
> may return noun form of itself, without causing infinite loop when
> evaluated
> with the noun flag set?
>
> Thanks and best regards,
> Yasuaki Honda, Chiba, Japan
>
> Imaxima and Imath maintainer
>
>
>
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