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Independence test

Distance covariance independence test for manifold-valued data.

manifold.dcov.test()
Distance covariance independence test for manifold-valued data.

Manifolds

Definition and retrieval of the manifolds supported by the package.

new_manifold()
Define a manifold for use in the package.
get_manifold()
Retrieve a manifold by name.
manifold_torus()
The flat torus manifold.
manifold_hyperbolic()
Hyperbolic space.
manifold_grassmann()
The Grassmann manifold.

Base point selection

Manifold-agnostic choice of the base point of the logarithmic map.

choose_base_point()
Choose a base point for the logarithmic map.
optimize_base_point()
Find a base point via multi-start optimization.

Torus

Geometry of the flat torus, with points represented in [0,1)^d.

is_in_torus()
Check that data lies in the torus representation [0,1)^d.
log_map_torus()
Map torus data to the tangent space at a base point.
dist_torus()
Torus distance from a data set to a point.
is_valid_torus()
Check whether a base point is valid for a torus data set.
auto_base_point_torus()
Find a torus base point via the maximal-gap method.
optimize_base_point_torus()
Find a torus base point via multi-start optimization.
largest_gap_point_torus()
Midpoint of the largest gap on the circle [0,1).

Hyperbolic space

Geometry of the hyperbolic space in the hyperboloid model.

is_in_hyperbolic()
Check that data lies on the hyperboloid.
log_map_hyperbolic()
Map hyperbolic data to the tangent space at a base point.
exp_map_hyperbolic()
Map tangent vectors to hyperbolic space.
dist_hyperbolic()
Hyperbolic distance from a data set to a point.
is_valid_hyperbolic()
Check whether a base point is valid for a hyperbolic data set.
auto_base_point_hyperbolic()
Find a hyperbolic base point via the Lorentzian centroid.
optimize_base_point_hyperbolic()
Find a hyperbolic base point via multi-start optimization.

Grassmann manifold

Geometry of the Grassmann manifold Gr(n, k), with points represented by Stiefel matrices.

is_in_grassmann()
Check that data lies on the Grassmann manifold.
log_map_grassmann()
Map Grassmann data to the tangent space at a base point.
exp_map_grassmann()
Map tangent vectors to the Grassmann manifold.
dist_grassmann()
Grassmann distance from a data set to a point.
is_valid_grassmann()
Check whether a base point is valid for a Grassmann data set.
auto_base_point_grassmann()
Find a Grassmann base point via the projection mean.
optimize_base_point_grassmann()
Find a Grassmann base point via multi-start optimization.

Center-outward transform

Multidimensional ranks in the unit ball (Hallin et al. 2021).

center_outward_transform()
Center-outward transform.
build_ball_grid()
Build a regular grid on the unit ball.
optimal_assignment()
Solve the optimal L2 assignment between data and grid.

Utilities

Helper functions for data preparation.

align_sample_sizes()
Align sample sizes of two data sets.