Intersection between line and circle

Please check the image above

I need to find the intersection point of the line with the circle 3 and circle 4.

If I use linecirc() command, i get the values of circle 1 also.

Is there any other command to get the required values ?

Thanks in advance

Answer 1

[Image Analyst]

Each circle with have either 0, 1, or 2 intersection points. Do you have the formula for each circle, meaning it's center coordinates and radius ? If seems like knowing the formulas for the lines you might be able to use fzero() to find the intersection point(s).

By the way, what toolbox is linecirc() in? I don't have it.

[Selva]

Thanks for the response

linecirc() comes under mapping toolbox

I have the center and radius of all circles

[Image Analyst]

I will add it to the Products list for you. Does that give the 0, 1, or 2 intersection points?

[Selva]

2 intersection points if it cuts the circle

2 same points if its a tangent

Nan if its does not intersect with the circle

Answer 2

[Matt J]

Find all points of intersection and write each in the form

 P_intersection = P1+t*(P2-P1)

where t is a scalar parameter. Solve for each t by doing

t = (P2-P1)\(P_intersection-P1)

Then discard all intersections other than the ones for which 0<=t<=1. The intersections that remain will all lie on the line segment between P1 and P2.