Re: series expansions in two variables problem
- To: mathgroup at smc.vnet.net
- Subject: [mg39513] Re: [mg39504] series expansions in two variables problem
- From: BobHanlon at aol.com
- Date: Fri, 21 Feb 2003 04:07:29 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2/20/03 5:56:12 AM, mc799 at ic.ac.uk writes:
> I'm expanding an expression in two variables (sigma and epsilon, say),
> but am having trouble persuading Mathematica to chuck away terms of
> form epsilon*sigma.
>
> ie I'm getting
>
> A + B*sigma + C*epsilon + D*sigma*epsilon + O(sigma^2) + O(epsilon^2)
>
> and I'd like very much to lose the D terms.
>
> does anyone have any suggestions?
>
(Series[Exp[x + y], {x, 0, 3}, {y, 0, 3}] //
Normal // Expand) /.
x^n_.*y^m_. :> 0
Bob Hanlon