  Leptonic mixing patterns are usually extracted on the basis of groups or
algebraic structures. In this paper, we introduce an alternative geometric
method to study the correlations between the leptonic mixing parameters. At the
3$\sigma$ level of the recent global fit data of neutrino oscillations, the
distribution of the scattered points of the angles between the vectors, which
are constructed by the element of the leptonic mixing matrix, is analysed. We
find that the scattered points are concentrated on several special regions.
Using the data in these regions, correlations of the leptonic mixing angles and
the Dirac CP violating phase are obtained. The implications of the correlations
are shown through the predicted flavor ratio of high-energy astrophysical
neutrinos (HANs) at Earth.
