Re: Beginner question: operating on piecewise defined functions
- To: mathgroup at smc.vnet.net
- Subject: [mg41623] Re: Beginner question: operating on piecewise defined functions
- From: Peter Breitfeld <phbrf at t-online.de>
- Date: Thu, 29 May 2003 08:13:48 -0400 (EDT)
- References: <bb1v7e$9hc$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Jan Rychter schrieb:
> If I define a piecewise function as, say:
>
> f[x_] := 1/x^2 /; x >= 1
> f[x_] := 1 /; x < 1
>
> then how can I get Mathematica to operate on it, as in:
>
> Limit[f[x], {x->Infinity}]
>
> Just trying that returns the expression unevaluated, even though
> defining:
>
> g[x_] := 1/x^2
>
[*** snipp ***]
Try this
f[x_]=1/x^2 UnitStep[x-1]+UnitStep[1-x]
Needs["Calculus`Limit`"]
Lim[f[x],x->Infinity]
returns 0.
Without loading Calculus`Limit` it doesn't work.
Gruß Peter
--
=--=--=--=--=--=--=--=--=--=--=--=--=--= http://home.t-online.de/home/phbrf
Peter Breitfeld, Bad Saulgau, Germany Meinen GnuPG/PGP-5x Key gibts dort