Re: How to use SeriesCoefficient to define new functions
- To: mathgroup at smc.vnet.net
- Subject: [mg122746] Re: How to use SeriesCoefficient to define new functions
- From: Xiaojun <tigertooth4 at gmail.com>
- Date: Wed, 9 Nov 2011 06:25:27 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <j9b6vs$4u6$1@smc.vnet.net>
Sorry for the unicode character issue: "=EB" should be greek letter
"lambda". Thanks in advance!
On Nov 8, 8:23 pm, Xiaojun <tigertoo... at gmail.com> wrote:
> Hi,
>
> I want to define new functions from the =EB-expansion of an exponential
> function as follows:
>
> SchurGenerator := Normal[Series[ Exp[x1*=EB + x2*=EB^2 + x3*=EB^3=
], {=EB, 0,
> 3}]].
>
> Each coefficient may define a function of x1, x2, and x3, which I
> think should be expressed
> as, for example:
>
> p2[x1_, x2_, x3_] := SeriesCoefficient[SchurGenerator, {=EB, 0, 2}=
].
>
> However, it doesn't seem to work. Since the expected output of
> p2[y1,y2,y3] should be
>
> y1^2/2 + y2. But the real output is still x1^2/2 + x2.
>
> How to define new functions from the expansion coefficients? I
> appreciate your help !
>
> --
> Best wishes,
> Liu Xiaojun