Re: Calculating the area surrounded by a closed contour curve.
- To: mathgroup at smc.vnet.net
- Subject: [mg35921] Re: [mg35906] Calculating the area surrounded by a closed contour curve.
- From: Andrzej Kozlowski <andrzej at platon.c.u-tokyo.ac.jp>
- Date: Thu, 8 Aug 2002 06:06:11 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I assume you are not asking for the formula for the area of the disk of
unit radius, are you? I will assume that what you are asking is for a
way to compute the area of a region described by inequalities using
Mathematica, of course. In your case we have just the inequality
x^2+y^2<=1. One way to do it is by using the package
Calculus`Integration`:
<< Calculus`Integration`
Chop[Integrate[Boole[x^2 + y^2 â?¤ 1], {x, -1.5, 1.5}, {y, -1.5, 1.5}]]
3.14159
The Chop is needed to get rid of infinitesimal imaginary parts that
often appear in numerical computations.
Andrzej Kozlowski
On Wednesday, August 7, 2002, at 06:59 PM, Jun Lin wrote:
> Does anybody know how to calculate the area surrounded by a closed
> contour? For example, using ContourPlot[x^2+y^2,
> {x,-1.5,1.5},{y,-1.5,1.5},Contours->{1}], I create a circular contour
> of unity radius. How can I further calculate the area of the region
> surrounded by the contour? Thanks very much for your help.
>
> Jun Lin
>
>