[mg14735] Re: [mg14718] Multi-Variate Taylor Series Expansions

[me]

One must use a trick to obtain multivariate Taylor polynomials. Try

Normal[Series[f[x + t h, y + t k], {t, 0, 3}]] /. t -> 1

--Lou Talman
Department of Mathematical and Computer Sciences
Campus Box 38
Metropolitan State College of Denver
PO Box 173362
Denver CO 80217-3362

http://clem.mscd.edu/~talmanl

> Date: Tue, 10 Nov 1998 01:21:08 -0500
> From: Tom Bell <tom...@stanford.edu>
To: math...@smc.vnet.net
> To: math...@smc.vnet.net
> Subject: [mg14735] [mg14718] Multi-Variate Taylor Series Expansions
> Mime-Version: 1.0
>
>
> Is there a function in Mathematica that will do multi-variate Taylor
> series
>
> expansions? For example, suppose I have
>
> function = F(x + dx, t + dt)
>
> then the expansion to second order about (x,t) should look something
> like
>
> expansion = F(x,t) + dx D(F,x) + dt D(F,t) + (1/2) dx^2 D(F,{x,2}) +
>
> dx dt D(F,{x,t}) + (1/2) dt^2 D(F,{t,2}) + O(dx^3) + O(dt^3)
>
> The situation gets a little more complicated: the function may look like
>
> F(x + G(x + dx, t + dt), t + dt) and so on, so that the expansion should
> be
>
> recursive. After expanding F, the function should keep going back and
> expending G until no
>
> further expansions can be done.
>
> Please reply to tom...@stanford.edu, and thanks in advance for your
> help.
>
> ----------------------------------------------------------------
> Thomas (Tom) Bell
> Gravity Probe-B, H.E.P.L. tom...@stanford.edu
> Stanford University 136D Escondido Village
> Stanford, CA
> 94305-4085 Stanford, CA 94305 650/725-6378 (o)
> 650/497-4230 (h) 650/725-8312 (fax)
>