Re: computing the area inside a contour plot
- To: mathgroup at smc.vnet.net
- Subject: [mg57615] Re: [mg57580] computing the area inside a contour plot
- From: "Caffa Vittorio Dr." <Caffa at iabg.de>
- Date: Thu, 2 Jun 2005 05:16:51 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
The following function can be used to compute the area of a polygon:
PolygonArea::usage = "PolygonArea[{pt1,
pt2, ...}] gives the area of a polygon. The area is defined to be
positive if the points are arranged in a counterclockwise order.";
PolygonArea[pnts : {{_, _} ..}] := Module[{x, y},
{x, y} = Transpose[pnts];
1/2Total[x RotateLeft[y] - RotateLeft[x]y]]
PolygonArea[{{0, 0}, {4, 0}, {3, 2}}]
4
See also: http://mathworld.wolfram.com/Polygon.html
Cheers, Vittorio
>-----Original Message-----
>From: I. I. [mailto:ibrahiim at email.uc.edu]
To: mathgroup at smc.vnet.net
>Sent: Wednesday, June 01, 2005 12:03 PM
>Subject: [mg57615] [mg57580] computing the area inside a contour plot
>
>hi,
>
>I have a plot of data points on a set of x and y coordinate axes.
These
>data points form a contour (it sort of looks like a "blob" of points).
I
>would like to compute the area inside this contour using Mathematica.
Any
>help would be really appreciated.
>
>
>Thank you,
>
>I. I.