Checking given point in circle

How to write function for checking if a given point (x, y) is within the circle with a centre at (p, q) and radius, r?

Answer 1

[Star Strider]

I would begin with the inpolygon function.

Answer 2

[DGM]

Depending on the context, there are probably more purpose-built tools, but you can do it in a very basic manner just the same.

center = [5 5];
radius = 10;

points = [10 10; 10 15];

isincircle = sum((center-points).^2,2) <= radius^2

isincircle = 2×1 logical array
   1
   0