The forumla might be right, looks a bit long to me :), there are better/other ways...
http://mathforum.org/library/drmath/sets/select/dm_center_circle.html Ries On Mar 24, 2010, at 1:58 PM, Jim Wilkin wrote: > Makes me think about how a three point arc in made in a cad program. > > Przemek Klosowski wrote: >> On Mon, Mar 22, 2010 at 9:35 PM, Alexander Brock >> <[email protected]> wrote: >> >> >>> I don't know such a script, but if you just want to calculate the >>> center, here is a description of the solution: >>> http://mathforum.org/library/drmath/view/55233.html >>> >>> This is not the only solution, I'm currently trying to find a closed >>> formula which is easy to implement. >>> >>> >> I haven't cross-checked this, but inputting this into Maxima: >> >> solve([(x1-h)^2 + (y1-k)^2 = r^2, (x2-h)^2 + (y2-k)^2 = r^2, (x3-h)^2 >> + (y3-k)^2 = r^2], [h, k, r]); >> >> results in: >> >> [h=-((y2-y1)*y3^2+(-y2^2+y1^2-x2^2+x1^2)*y3+y1*y2^2+(-y1^2+x3^2- >> x1^2)*y2+(x2^2-x3^2)*y1)/ >> ((2*x2-2*x1)*y3+(2*x1-2*x3)*y2+(2*x3-2*x2)*y1), >> k=((x2-x1)*y3^2+(x1-x3)*y2^2+(x3-x2)*y1^2+(x2-x1)*x3^2+(x1^2- >> x2^2)*x3+x1*x2^2-x1^2*x2)/ >> ((2*x2-2*x1)*y3+(2*x1-2*x3)*y2+(2*x3-2*x2)*y1), >> r=(sqrt(y2^2*y3^4-2*y1*y2*y3^4+y1^2*y3^4+x2^2*y3^4-2*x1*x2*y3^4+x1^2* >> y3^4-2*y2^3*y3^3+2*y1*y2^2*y3^3+2*y1^2*y2*y3^3-2*x2^2*y2*y3^3+4*x1*x2 >> *y2*y3^3-2*x1^2*y2*y3^3-2*y1^3*y3^3-2*x2^2*y1*y3^3+4*x1*x2*y1*y3^3-2* >> x1^2*y1*y3^3+y2^4*y3^2+2*y1*y2^3*y3^2-6*y1^2*y2^2*y3^2+2*x3^2*y2^2*y3 >> ^2-2*x2*x3*y2^2*y3^2-2*x1*x3*y2^2*y3^2+2*x2^2*y2^2*y3^2-2*x1*x2*y2^2* >> y3^2+2*x1^2*y2^2*y3^2+2*y1^3*y2*y3^2-4*x3^2*y1*y2*y3^2+4*x2*x3*y1*y2* >> y3^2+4*x1*x3*y1*y2*y3^2+2*x2^2*y1*y2*y3^2-8*x1*x2*y1*y2*y3^2+2*x1^2*y >> 1*y2*y3^2+y1^4*y3^2+2*x3^2*y1^2*y3^2-2*x2*x3*y1^2*y3^2-2*x1*x3*y1^2*y >> 3^2+2*x2^2*y1^2*y3^2-2*x1*x2*y1^2*y3^2+2*x1^2*y1^2*y3^2+2*x2^2*x3^2*y >> 3^2-4*x1*x2*x3^2*y3^2+2*x1^2*x3^2*y3^2-2*x2^3*x3*y3^2+2*x1*x2^2*x3*y3 >> ^2+2*x1^2*x2*x3*y3^2-2*x1^3*x3*y3^2+x2^4*y3^2-2*x1*x2^3*y3^2+2*x1^2*x >> 2^2*y3^2-2*x1^3*x2*y3^2+x1^4*y3^2-2*y1*y2^4*y3+2*y1^2*y2^3*y3-2*x3^2* >> y2^3*y3+4*x1*x3*y2^3*y3-2*x1^2*y2^3*y3+2*y1^3*y2^2*y3+2*x3^2*y1*y2^2* >> y3+4*x2*x3*y1*y2^2*y3-8*x1*x3*y1*y2^2*y3-4*x2^2*y1*y2^2*y3+4*x1*x2*y1 >> *y2^2*y3+2*x1^2*y1*y2^2*y3-2*y1^4*y2*y3+2*x3^2*y1^2*y2*y3-8*x2*x3*y1^ >> 2*y2*y3+4*x1*x3*y1^2*y2*y3+2*x2^2*y1^2*y2*y3+4*x1*x2*y1^2*y2*y3-4*x1^ >> 2*y1^2*y2*y3-2*x2^2*x3^2*y2*y3+4*x1*x2*x3^2*y2*y3-2*x1^2*x3^2*y2*y3+4 >> *x1*x2^2*x3*y2*y3-8*x1^2*x2*x3*y2*y3+4*x1^3*x3*y2*y3-2*x1^2*x2^2*y2*y >> 3+4*x1^3*x2*y2*y3-2*x1^4*y2*y3-2*x3^2*y1^3*y3+4*x2*x3*y1^3*y3-2*x2^2* >> y1^3*y3-2*x2^2*x3^2*y1*y3+4*x1*x2*x3^2*y1*y3-2*x1^2*x3^2*y1*y3+4*x2^3 >> *x3*y1*y3-8*x1*x2^2*x3*y1*y3+4*x1^2*x2*x3*y1*y3-2*x2^4*y1*y3+4*x1*x2^ >> 3*y1*y3-2*x1^2*x2^2*y1*y3+y1^2*y2^4+x3^2*y2^4-2*x1*x3*y2^4+x1^2*y2^4- >> 2*y1^3*y2^3-2*x3^2*y1*y2^3+4*x1*x3*y1*y2^3-2*x1^2*y1*y2^3+y1^4*y2^2+2 >> *x3^2*y1^2*y2^2-2*x2*x3*y1^2*y2^2-2*x1*x3*y1^2*y2^2+2*x2^2*y1^2*y2^2- >> 2*x1*x2*y1^2*y2^2+2*x1^2*y1^2*y2^2+x3^4*y2^2-2*x2*x3^3*y2^2-2*x1*x3^3*y2^2+2*x2^2*x3^2*y2^2+2*x1*x2*x3^2*y2^2+2*x1^2*x3^2*y2^2-4*x1*x2^2*x3*y2^2+2*x1^2*x2*x3*y2^2-2*x1^3*x3*y2^2+2*x1^2*x2^2*y2^2-2*x1^3*x2*y2^2+x1^4*y2^2-2*x3^2*y1^3*y2+4*x2*x3*y1^3*y2-2*x2^2*y1^3*y2-2*x3^4*y1*y2+4*x2*x3^3*y1*y2+4*x1*x3^3*y1*y2-2*x2^2*x3^2*y1*y2-8*x1*x2*x3^2*y1*y2-2*x1^2*x3^2*y1*y2+4*x1*x2^2*x3*y1*y2+4*x1^2*x2*x3*y1*y2-2*x1^2*x2^2*y1*y2+x3^2*y1^4-2*x2*x3*y1^4+x2^2*y1^4+x3^4*y1^2-2*x2*x3^3*y1^2-2*x1*x3^3*y1^2+2*x2^2*x3^2*y1^2+2*x1*x2*x3^2*y1^2+2*x1^2*x3^2*y1^2-2*x2^3*x3*y1^2+2*x1*x2^2*x3*y1^2-4*x1^2*x2*x3*y1^2+x2^4*y1^2-2*x1*x2^3*y1^2+2*x1^2*x2^2*y1^2+x2^2*x3^4-2*x1*x2*x3^4+x1^2*x3^4-2*x2^3*x3^3+2*x1*x2^2*x3^3+2*x1^2*x2*x3^3-2*x1^3*x3^3+x2^4*x3^2+2*x1*x2^3*x3^2-6*x1^2*x2^2*x3^2+2*x1^3*x2*x3^2+x1^4*x3^2-2*x1*x2^4*x3+2*x1^2*x2^3*x3+2*x1^3*x2^2*x3-2*x1^4*x2*x3+x1^2*x2^4-2*x1^3*x2^3+x1^4*x2^2))/((2*x2-2*x1)*y3+(2*x1-2*x3)*y2+(2*x3-2*x2)*y1)] >> >> ------------------------------------------------------------------------------ >> Download Intel® Parallel Studio Eval >> Try the new software tools for yourself. Speed compiling, find bugs >> proactively, and fine-tune applications for parallel performance. >> See why Intel Parallel Studio got high marks during beta. >> http://p.sf.net/sfu/intel-sw-dev >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users regards, Ries van Twisk ------------------------------------------------------------------------------------------------- tags: Freelance TYPO3 Glassfish JasperReports JasperETL Flex Blaze-DS WebORB PostgreSQL DB-Architect email: [email protected] web: http://www.rvantwisk.nl/ skype: callto://r.vantwisk Phone: +1-810-476-4196 Cell: +593 9901 7694 SIP: +1-747-690-5133 regards, Ries van Twisk ------------------------------------------------------------------------------------------------- tags: Freelance TYPO3 Glassfish JasperReports JasperETL Flex Blaze-DS WebORB PostgreSQL DB-Architect email: [email protected] web: http://www.rvantwisk.nl/ skype: callto://r.vantwisk Phone: +1-810-476-4196 Cell: +593 9901 7694 SIP: +1-747-690-5133 ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
