Which line is the first line that has an intersection with another line? or what is the order of the intersectection points?

Hello,

I have a problem in my code and I have simplified it as below:

x=[12;25;7];
y=[6;31;15];
xd=[5;40;NaN;2;11];
yd=[13;16;NaN;8;9];

I have the above points I want to calculate the intersection, between line 1 and line 2,3. I used polyxpoly.

Here is my question, how can I undesrtand which line is the first iinterseted line while moving from point (x,y)1 to (x,y)2. Is it line 2 or line 3?

Thanks a lot

Answer 1

[darova]

Use third output argument of polyxpoly

[xc,yc,ix] = polyxpoly(x,y,xd,yd)
% ix(:,1) - number of intersected segment in [x,y] data
% ix(:,2) - number of intersected segment in [xd,yd] data