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: Fri, 3 Apr 2009 20:13:33 -0500 (EST)
- 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
>