  By using the independence structure of points following a determinantal point
process, we study the radii of the spherical ensemble, the truncation of the
circular unitary ensemble and the product ensemble with parameter n and k. The
limiting distributions of the three radii are obtained. They are not the
Tracy-Widom distribution. In particular, for the product ensemble, we show that
the limiting distribution has a transition phenomenon: when k/n -> 0, k/n -> a
in (0,infty) and k/n -> infty, the liming distribution is the Gumbel
distribution, a new distribution $\mu$ and the logarithmic normal distribution,
respectively. The cumulative distribution function (cdf) of mu is the infinite
product of some normal distribution functions. Another new distribution nu is
also obtained for the spherical ensemble such that the cdf of nu is the
infinite product of the cdfs of some Poisson-distributed random variables.
