# [Maxima] operations on polynomial expressions

Richard Fateman fateman at cs.berkeley.edu
Tue Dec 19 11:21:09 CST 2006

```I don't know why this task needs extra programs or many arguments.

Consider
ans:[]\$
makealist(r,x):= for i:hipow(r,x) step -1 thru 0 do
ans:cons(ratcoef(r,x,i),ans)\$

makealist(a*x^3+b*x+c,x);  -->  [c,b,0,a]

If the argument r is originally put in rational form, e.g.  r:rat(r,x)\$
this should be very fast.

I don't know what you want to do with the coefficients, so I show how to put
them in a list.  You can multiply them by x^i or something else, and sum
them up, if you wish.  Or you can just use ratexpand(r), as I've mentioned
before here.
RJF

> -----Original Message-----
> From: maxima-bounces at math.utexas.edu [mailto:maxima-
> bounces at math.utexas.edu] On Behalf Of Fabrizio Caruso
> Sent: Tuesday, December 19, 2006 9:00 AM
> To: Andrej Vodopivec
> Cc: maxima at math.utexas.edu; Chris Sangwin
> Subject: Re: [Maxima] operations on polynomial expressions
>
> Hi
>
> load(coeflist) produces the following error:
> "
> /usr/share/maxima/5.10.0/share/contrib/format/coeflist.lisp
>  -- an error.  Quitting.  To debug this try debugmode(true);
> "
> I am using Maxima 5.10.0 and clisp.
> Note: gcl does not let me call functions with a
> high number of arguments.
>
> My original problem was to write a multivariate polynomial
> as a sum of monomials with coefficients free of the variables.
>
>   Fabrizio
>
> On Sat, 25 Nov 2006, Andrej Vodopivec wrote:
>
> > Also load the coeflist package:
> >
> > (%i3) a*(x+y+z)^2 + b*(x-y-z)^2;
> > (%o3) a*(z+y+x)^2+b*(-z-y+x)^2
> > (%i4) format(%, %poly(x,y,z));
> > (%o4) (b+a)*z^2+(2*b+2*a)*y*z+(2*a-2*b)*x*z+(b+a)*y^2+(2*a-
> 2*b)*x*y+(b+a)*x^2
> >
> > Andrej
> >
> > On 11/25/06, Chris Sangwin <sangwinc at for.mat.bham.ac.uk> wrote:
> > >
> > > Fabrizio,
> > >
> > > I suggest you look at the "format" package.  It is useful for these
> kinds
> > > of manipulations.
> > >
> > >
> > > There is some documentation online at
> > >
> > > http://matsrv3.bham.ac.uk/scripts/maxima/format/format.pdf
> > >
> > > (I can't find it in the "proper" place, sorry!)
> > >
> > > Chris
> >
> _______________________________________________
> Maxima mailing list
> Maxima at math.utexas.edu
> http://www.math.utexas.edu/mailman/listinfo/maxima
```