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RECORD CircleData pos PD; num radius; ENDRECORD
FUNC CircleData SearchCircle(pos P1,pos P2,pos P3)
VAR num a1;
VAR num b1;
VAR num c1;
VAR num d1;
VAR num a2;
VAR num b2;
VAR num c2;
VAR num d2;
VAR num a3;
VAR num b3;
VAR num c3;
VAR num d3;
VAR num x1;
VAR num y1;
VAR num z1;
VAR num x2;
VAR num y2;
VAR num z2;
VAR num x3;
VAR num y3;
VAR num z3;
VAR CircleData CD;
x1:=p1.x;
y1:=p1.y;
z1:=p1.z;
x2:=p2.x;
y2:=p2.y;
z2:=p2.z;
x3:=p3.x;
y3:=p3.y;
z3:=p3.z;
a1:=(y1*z2-y2*z1-y1*z3+y3*z1+y2*z3-y3*z2);
b1:=-(x1*z2-x2*z1-x1*z3+x3*z1+x2*z3-x3*z2);
c1:=(x1*y2-x2*y1-x1*y3+x3*y1+x2*y3-x3*y2);
d1:=-(x1*y2*z3-x1*y3*z2-x2*y1*z3+x2*y3*z1+x3*y1*z2-x3*y2*z1);
a2:=2*(x2-x1);
b2:=2*(y2-y1);
c2:=2*(z2-z1);
d2:=x1*x1+y1*y1+z1*z1-x2*x2-y2*y2-z2*z2;
a3:=2*(x3-x1);
b3:=2*(y3-y1);
c3:=2*(z3-z1);
d3:=x1*x1+y1*y1+z1*z1-x3*x3-y3*y3-z3*z3;
cd.PD.x:=-(b1*c2*d3-b1*c3*d2-b2*c1*d3+b2*c3*d1+b3*c1*d2-b3*c2*d1)
/(a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1);
cd.PD.y:=(a1*c2*d3-a1*c3*d2-a2*c1*d3+a2*c3*d1+a3*c1*d2-a3*c2*d1)
/(a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1);
cd.PD.z:=-(a1*b2*d3-a1*b3*d2-a2*b1*d3+a2*b3*d1+a3*b1*d2-a3*b2*d1)
/(a1*b2*c3-a1*b3*c2-a2*b1*c3+a2*b3*c1+a3*b1*c2-a3*b2*c1);
cd.radius:=sqrt((x1-cd.PD.x)*(x1-cd.PD.x)+(y1-cd.PD.y)*(y1-cd.PD.y)+(z1-cd.PD.z)*(z1-cd.PD.z));
cd.radius:=sqrt((x2-cd.PD.x)*(x2-cd.PD.x)+(y2-cd.PD.y)*(y2-cd.PD.y)+(z2-cd.PD.z)*(z2-cd.PD.z));
cd.radius:=sqrt((x3-cd.PD.x)*(x3-cd.PD.x)+(y3-cd.PD.y)*(y3-cd.PD.y)+(z3-cd.PD.z)*(z3-cd.PD.z));
RETURN CD;
ENDFUNC
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