Finding the intersec point using InterX?

I am trying to find the intersect point of two lines using "InterX".

More concretely, I want to find the intersect point of the line L1 which two coordinates are x1=1,y1=1 and x2=3 y2=6

and the line L2 which two coordinates are x1=-2 y1=8 and x2=2 y2=-1

I don´t know if I understanded well the "InterX" function, but here is the code I have executed:

hold on
x=linspace(-30,30)
L1=[1 3;
1 6]

L2=[-2 2;
8 -1]

P=InterX(L1,L2);

plot(L1)
plot(L2)
plot(P,'ro')

And the result Matlab gives to me is completly absurd, in the following image:

What am I doing wrong? How can I properly use the "InterX" function? I have searched in the community but I didn´t understand it very well as you can see

Answer 1

[KSSV]

You should read the documentation/ help given in the InterX function. Your curves/ data points should be such that :

L1 = [x11 x12 ; y11 y12] ;

L2 = [x21 x22 ; y21 y22] ;

L1=[1 3;
1 6]

L2=[-2 2;
8 -1]

P=InterX(L1,L2);

figure
hold on
plot(L1(1,:),L1(2,:),'r')
plot(L2(1,:),L2(2,:),'b')
plot(P(1),P(2),'ro')

[ErikJon Pérez Mardaras]

And how it would be if I would like to know all intersect points between two elements?. For instance, let's say I would like to know the two intersec points between a line and a circle as shown below.

I don`t know why matlab only shows me one point of intersec. I have read the "help" text of "InterX" function but I think I didn´t get it. Here is the code I have introduced:

How can I find both points of intersec?

axis equal
hold on

caca=2*pi();
ang=linspace(0,caca);
xp=5*cos(ang);
yp=5*sin(ang);

circ=[xp;yp];
plot(xp,yp,'r');


L1=[-7 7; 2 2];                      
plot(L1(1,:),L1(2,:),'b')

P=InterX(circ,L1);

plot(P(1),P(2),'go');

[KSSV]

You are getting two points. You are plotting it wrong.

plot(P(1,:),P(2,:),'go');

[ErikJon Pérez Mardaras]

thanks!