hank you very much for your help, and it really help me a lot.
I have read your program carefully, some of them are not totaly understand.
1．Such as "axycurve := x -> CurveFitting:-ArrayInterpolation(axy, x, method = spline, extrapolate) "
It means I can get the new x and y which were splined. But how can I view value of x, y?
> fsolve(axycurve-cxycurve,min(cx)..max(cx)); # extrapolation
Why they have different value? They should have the same value no matter from min(ax)..max(ax) or min(cx)..max(cx)
3．I have another question, If I want to know the (x,y) of the intersection, in your help I have calculate the x value, how could I calculate y value?