On 10/03/06, Robert Dodier <robert.dodier at gmail.com> wrote:
> hi sarah,
>
> > I've got a really *really* long expression in 16 variables, but I'm
> > only interested in those parts of the expression that contain 4 of
> > those 16 variables. Is there any way to get maxima to return the
> > subexpression containing only those variables which I'm interested in?
>
> can you show a simplified version of the problem?
> that might help people like me come up with something ...
Hi all,
I think "isolate" is close to the answer. To reply to Robert's
question, say we have an expression:
xyz^2 + y^2z + x^2y + zx
and we're only interested in the terms containing z, then we want
maxima to return:
xyz^2 + y^2z + zx
Here's a transcript with isolate:
(%i1) xyz^2 + z.y^2 + y.x^2 + zx;
2 2 2
(%o1) zx + z . y + y . x + xyz
(%i2) isolate(%,z);
2 2
(%t2) zx + y . x + xyz
2
(%o2) z . y + %t2
(%i3)
Thanks for all your help!
Sarah
--
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