Circular disk inner squaring

Please use the slider to choose the radius and see the lattice of fully enclosed in the circle integer squares. With some radii (e.g. 5 or 13) you may notice tangency of the lattice and the circle. They may often look tangent, but if there is no specially indicated tangent point, the tangency does not take place. Check the indication of actual shortest distance between the lattice and the circle then, as well as some other numerical characteristics.