four dimensioal polynomial composition

*To*: mathgroup at smc.vnet.net*Subject*: [mg57165] four dimensioal polynomial composition*From*: "Christoph Lhotka" <lhotka at astro.univie.ac.at>*Date*: Thu, 19 May 2005 03:09:10 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hello ! I want to compose a four dimensional polynomial p(x,y,u,v) of some certain degree N with four other polynomials x->px(x,y,u,v), y->py(x,y,u,v), u->pu(x,y,u,v), v->pv(x,y,u,v) up to order N (p(px,py,pu,pv)) and extract all monomials of some certain order, say M (with respect to lambda). For this reason I introduce some artificial parameter lambda which holds terms together of equal order. I implement the polynomials using the SeriesData (which now has five expansion parameters) object and have the following question: Is there anywhere on the net some more detailed information of dealing with multivariates Series in Mathematica, I have not found yet. Is there a better way, when dealing with polynomials? Christoph University of Vienna Institute for Astronomy mail. lhotka at astro.univie.ac.at