Re: help in constructing a binomial consequence

*To*: mathgroup at smc.vnet.net*Subject*: [mg98276] Re: help in constructing a binomial consequence*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Sun, 5 Apr 2009 06:33:35 -0400 (EDT)*Organization*: Uni Leipzig*References*: <gr4jm9$ac5$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, if it must be that order and you cant give us the rule for that order you have to type it by hand otherwise With[{n = 3}, lst = Flatten[ Outer[Times, Table[x^i, {i, 0, n}], Table[y^j, {j, 0, n}]], 1] ] exponentSum[expr_] := Block[{ex, ey}, ex = Exponent[expr, x]; ey = Exponent[expr, y]; ex + ey ] and Sort[lst, exponentSum[#1] < exponentSum[#2] || OrderedQ[{#1, #2}] &] will do something that is very close to your ordering. Regards Jens Galina wrote: > Hello all, > I need to find an eigenvalues of the matrix M [N*N] where elements > are of the type F[i]*F[j]. I need help to construct the elements F[i] > which must be in the following order: F[1]=1, F[2]=x, F[3]=y, F[4] > =x^2, F[5]=x*y, F[6]=y^2, F[7]=y*x^2, F[8]=x*y^2, F[9]=x^3 and etc.... > Could someone help, please? > > Thanks a lot, > Galina >