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dipy.core.sphere_stats

Statistics on spheres

dipy.core.sphere_stats.eigenstats(points, alpha=0.050000000000000003)

Principal direction and confidence ellipse

Implements equations in section 6.3.1(ii) of Fisher, Lewis and Embleton, supplemented by equations in section 3.2.5.

Parameters :

points : arraey_like (N,3)

array of points on the sphere of radius 1 in \mathbb{R}^3

alpha : real or None

1 minus the coverage for the confidence ellipsoid, e.g. 0.05 for 95% coverage.

Returns :

centre : vector (3,)

centre of ellipsoid

b1 : vector (2,)

lengths of semi-axes of ellipsoid