Re: How to specify these limits in an integral?
- To: mathgroup at smc.vnet.net
- Subject: [mg63457] Re: How to specify these limits in an integral?
- From: dh <dh at metrohm.ch>
- Date: Sun, 1 Jan 2006 01:16:11 -0500 (EST)
- References: <dp5rch$rjs$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Konrad,
simply define a "characteristic function" of your region that is 1
inside and 0 outside. Then multiply the integrand with this function and
integrate over any convenient region large enough to contain the
original one.
E.g.:
f[x_,y_]:= If[x^2 + y^2 - 2x + 6y ==6,1,0];
Integrate[f[x,y] x y,{x,-3,5},{y,-7,1.1}]
Daniel
Konrad Den Ende wrote:
> I have a double integral of the function f = x * y. I'd
> like make Mathematica compute it's value over the
> disc specified by, let's say:
> x^2 + y^2 - 2x + 6y <=6
>
> I can carry out computation on paper, preparing the
> sutabile substitutions myself but i wonder if there's
> a way to shove it all into Mathematica and let it chew.
>
> Sincerely
> Konrad
>
>