Operations on Lie groupsΒΆ
manif supports the following operations with Lie groups,
Operation |
Code |
|
---|---|---|
Base Operation |
||
Inverse |
\(\bf\mathcal{X}^{-1}\) |
|
Composition |
\(\bf\mathcal{X}\circ\bf\mathcal{Y}\) |
|
Hat |
\(\boldsymbol\varphi^\wedge\) |
|
Act on vector |
\(\bf\mathcal{X}\circ{\bf v}\) |
|
Retract to group element |
\(\exp(\boldsymbol\varphi^\wedge)\) |
|
Lift to tangent space |
\(\log(\bf\mathcal{X})^\vee\) |
|
Manifold Adjoint |
\(\mathrm{Adj}(\bf\mathcal{X})\) |
|
Tangent adjoint |
\(\mathrm{adj}(\boldsymbol\varphi^\wedge)\) |
|
Composed Operation |
||
Manifold right plus |
\({\bf\mathcal{X}}\circ\exp(\boldsymbol\varphi^\wedge)\) |
|
Manifold left plus |
\(\exp(\boldsymbol\varphi^\wedge)\circ\bf\mathcal{X}\) |
|
Manifold right minus |
\(\log(\bf\mathcal{Y}^{-1}\circ\bf\mathcal{X})^\vee\) |
|
Manifold left minus |
\(\log(\bf\mathcal{X}\circ\bf\mathcal{Y}^{-1})^\vee\) |
|
Between |
\({\bf\mathcal{X}^{-1}}\circ{\bf\mathcal{Y}}\) |
|
Inner Product |
\(\langle\boldsymbol\varphi,\boldsymbol\tau\rangle\) |
|
Norm |
\(\left\lVert\boldsymbol\varphi\right\rVert\) |
|
Above, \({\bf\mathcal{X}}\) & \({\bf\mathcal{Y}}\) (X
& Y
) represent group elements,
\({\boldsymbol\varphi^\wedge}\) & \({\boldsymbol\tau^\wedge}\) represent elements in the Lie algebra of the Lie group,
\({\boldsymbol\varphi}\) & \({\boldsymbol\tau}\) (w
& t
) represent the same elements of the tangent space
but expressed in Cartesian coordinates in \(\mathbb{R}^n\),
and \(\mathbf{v}\) (v
) represents any element of \(\mathbb{R}^n\).