Re: how to get the area of circles

*To*: mathgroup at smc.vnet.net*Subject*: [mg74789] Re: [mg74751] how to get the area of circles*From*: anguzman at ing.uchile.cl*Date*: Thu, 5 Apr 2007 04:11:50 -0400 (EDT)*References*: <200704040753.DAA11559@smc.vnet.net>

Wow..... I don't know... But of course, there is always the numerical-and-extremely-inefficient-way. circles={{{a1,b1},rad1},{{a2,b2},rad2},....{{an,bn},radn}}; (*The list of circles*) {lsupx,linfx,lsupy,linfy}= {circles[[All,1,1]]+circles[[All,2]]//Max, circles[[All,1,1]]-circles[[All,2]]//Min, circles[[All,1,2]]+circles[[All,2]]//Max, circles[[All,1,2]]-circles[[All,2]]//Min} (*A rectangle that contains them*) <<Calculus`Integration` (*a package*) inside[{x_,y_}]=Boole[Or@@(Simplify[Norm[{x,y}-#[[1]] ]<#[[2]]&/@circles,Assumptions->{Element[x,Reals],Element[y,Reals]}])] (*a function that is 1 inside and zero otherwise*) NIntegrate[inside[{x,y}],{x,linfx,lsupx},{y,linfy,lsupx}] (*and the numerical integration*) It's slow. Atte. Andres Guzman doufunao <gaoshan2002 at gmail.com> ha escrito: > > hi guys, > > I'm working on a project. I need to calculate the area of many circles > in a 2D space which may overlap each other. > It's quite complicated. I am not sure whether mathematica can do this. > Is there any software/lib/package available already? > thanks. > > > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

**References**:**how to get the area of circles***From:*"doufunao" <gaoshan2002@gmail.com>