Packing Circles inside a Circle

Given unit circle, and a set of M smaller circles of radius r. Find the maximum radius of the smaller circles that allows them all to fit inside the unit circle without overlap.

I have the following circles packing in polygon example link

I want to change equations that say that all circles are inside the polygon

theta = 2*pi/N;       % Angle covered by each side of the polygon

phi = theta*(0:N-1)'; % Direction of the normal to the side of the polygon

polyEq = ( [cos(phi) sin(phi)]*x <= cdist-r );

to equations that say that all circles are inside the circle, but i don't know how. Can somebody help me?

Kind regards.

[Image Analyst]

The comments in that code say it already does what you want. Why do you need to change anything?