Re: simplifying complex polynomials

*To*: mathgroup at smc.vnet.net*Subject*: [mg13722] Re: [mg13699] simplifying complex polynomials*From*: Wouter Meeussen <eu000949 at pophost.eunet.be>*Date*: Wed, 19 Aug 1998 01:38:15 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Daniel, lets create a sum of terms: fa:=Apply[Plus,Table[(-1)^Random[Integer,{0,1}] y@@Table[Random[Integer,{-1, 1}],{3}] ,{36},{4}],1] ad let's make a rule: ruletwo=( a_Plus /;!MatchQ[(Plus@@(a/. -q->q/.Plus->List/. y->List)),{2,_,_}] ->{}) let's create a sample: fa (#/.ruletwo&)/@% %~DeleteCases~{} this gives the list fa cleaned up. wouter At 04:39 15-08-98 -0400, Daniel H. Steinberg wrote: >A friend of mine is trying to simplify polynomials which are sums of >monomials each of which is the product of terms which are y_[] and z_[] >where the [] is a vector like [1,1,2,1,5]. > >Her simplification rules are fairly straightforward -- but how do you >get Mathematica to do it. > >Rule 1: Each monomial must be quadratic in z (i.e. if it's not, replace >it by 0) > >Rule 2: Each monomial's vector subscripts must sum (over all z's and >y's) to the vector [1,2,2,2,1] (for example). If it doesn't the term >can be eliminated. > >Any thoughts? She's trying to process it as a list but this seems to be >further complicated by multiplicities. > >Thanks, Daniel > > Dr. Wouter L. J. MEEUSSEN w.meeussen.vdmcc at vandemoortele.be eu000949 at pophost.eunet.be