tree 158c721070938432f7bd0e5b2413bb60821fbd84
parent 3e1cc89f6341b003698c00c50280cd7ba1e6aa61
author Julio L. Paneque <jlpaneque94@gmail.com> 1659609670 +0200
committer Julio L. Paneque <jlpaneque94@gmail.com> 1660030578 +0200

Fix the Sphere and Line Manifold formulations

This PR changes the Sphere and Line Manifold formulations so that their
tangent spaces represent traveled angles (for the sphere and the line
direction vector) and traveled distance (for the line origin). These
magnitudes were previously halved according to "Hartley & Zisserman
(2nd Edition)", but in the majority of the state of the art this is not
done, following the convention that magnitudes in the tangent space of
the unit sphere represent geodesic distances traveled on that manifold.
The same scale factor appears in the Quaternion Manifold implementation
and will be studied in a further PR.

This PR also adds an additional case in the Sphere Minus operator when
hy_norm == 0. The value of y_minus_x was fixed to 0 but actually its
last term can also be Pi depending on y_last.

Finally, new unit tests for the Plus and Minus operator are added, along
with new tests for the 2D Sphere (a.k.a. Circle) Manifold.

Change-Id: I9456f1675b20da49bede5d6759aabf3cdfb26eae