Good day!
KR C v.8.3.12, KR C4, KR 60HA
I cannot understand what incorrect calculation of functions is connected with.
From where such rounding on the example of receiving the center of a circle for three points in space undertakes?
DEF TESTfct_3( )
DECL REAL X1, Y1, Z1, X2, Y2, Z2, X3, Y3, Z3
DECL REAL MA, MB, MC, MD, X21, Y21, Z21, X31, Y31, Z31, MQ1, MQ2, MQ3, MBY, MCZ
DECL REAL X0, Y0, Z0
X1 = -89.3200
Y1 = 1379.43
Z1 = 590.445
X2 = -48.0000
Y2 = 1452.19
Z2 = 591.265
X3 = -5.42000
Y3 = 1379.88
Z3 = 590.380
;
MA=Y3*(Z1-Z2)+Y1*(Z2-Z3)+Y2*(-Z1+Z3)
MB=X3*(-Z1+Z2)+X2*(Z1-Z3)+X1*(-Z2+Z3)
MC=X3*(Y1-Y2)+X1*(Y2-Y3)+X2*(-Y1+Y3)
MD=-X3*Y2*Z1+X2*Y3*Z1+X3*Y1*Z2-X1*Y3*Z2-X2*Y1*Z3+X1*Y2*Z3
X21=X2-X1
Y21=Y2-Y1
Z21=Z2-Z1
X31=X3-X1
Y31=Y3-Y1
Z31=Z3-Z1
MQ1=X1*X1+Y1*Y1+Z1*Z1
MQ2=X2*X2+Y2*Y2+Z2*Z2
MQ3=X3*X3+Y3*Y3+Z3*Z3
MBY=MQ3*(-Z1+Z2)+MQ2*(Z1-Z3)+MQ1*(-Z2+Z3)
MCZ=MQ3*(Y1-Y2)+MQ1*(Y2-Y3)+MQ2*(-Y1+Y3)
X0=(2*MA*MD+MB*MBY+MC*MCZ)/(2*(MA*MA+MB*MB+MC*MC))
Y0=-((MQ1*Z21-MQ3*Z21+2*X0*X31*Z21-MQ1*Z31+MQ2*Z31-2*X0*X21*Z31)/(2*(Y31*Z21-Y21*Z31)))
Z0=(-MQ1*Y21+MQ3*Y21-2*X0*X31*Y21+MQ1*Y31-MQ2*Y31+2*X0*X21*Y31)/(2*(-Y31*Z21+Y21*Z31))
END
it has to turn out:
X0 = -47.4992543168
Y0 = 1403.7947203
Y0 = 590.696145504
Perhaps there are settings of accuracy of calculation?
It is possible to look at it on a simple example of simplification of function when viewing "Indication of variables - on one" for MA:
MA=-Y2*Z1+Y3*Z1+Y1*Z2-Y3*Z2-Y1*Z3+Y2*Z3
-5.125
MA= Z1*(Y3-Y2)+Z2*(Y1-Y3)+Z3*(Y2-Y1)
-5.09375
MA=Y1*(Z2-Z3)+Y2*(Z3-Z1)+Y3*(Z1-Z2)
-5.09851074
And the correct MA value should turn out: -5.0983999999
Why such difference in results and how to solve a problem?
I apologize for a non-standard design of a question. I badly know English. 
