lib/Documentation/docs-sonyckson/3puntos1circulo.cpp

   1 point center(double x1, double y1, double x2, double y2, double x3, double y3){
   2         point p;
   3         double A1 = x1-x2;
   4         double A2 = x2-x3;
   5         double B1 = y1-y2;
   6         double B2 = y2-y3;
   7         double C1 = (A1*(x1+x2) + B1*(y1+y2))/2;
   8         double C2 = (A2*(x2+x3) + B2*(y2+y3))/2;
   9         double d = A1*B2-A2*B1;
  10         if(fabs(d)<1e-7)return p;
  11         double y = (A1*C2-A2*C1)/d;
  12         double x = -(B1*C2-B2*C1)/d;
  13         p.x = x, p.y = y;
  14         return p;
  15 }