Is there a way to get the intersection point between two curves in Matlab?

Dear All,

from a contour I get returned the point relative to two iso-curves on a x-y plane. Then, I try to get the intersection point between these two curves. If they behave as a function, then I use the interp1 to find this point. However, in general, it happens that the curves are not functions and this solution no longer works. I tried to use spline but I got a similar problem since the error message looks like:

 Error using chckxy (line 51)
The data sites should be distinct.

Error in spline (line 53) [x,y,sizey,endslopes] = chckxy(x,y);

Do you have any suggestions on how to solve this problem?

Many thanks in advance.

Answer 1

[Luffy]

If you have the equation to two curves,you can find the point manually: if y1 & y2 are their equations:

idx = find(y1 - y2 < eps, 1); %// Index of coordinate in array
px = x(idx);
py = y1(idx);
plot(px,py,'or','MarkerSize',18);

If not take a look at this: Curve intersections

Answer 2

[somya bhatnagar]

if the values intersection point to be found lies in a polynomial then you can use

[xi,yi]=polyxpoly(x1,y1,x2,y2);