navlie.lib.states.VectorState¶

class navlie.lib.states.VectorState(value: ndarray, stamp: float | None = None, state_id=None)¶

Bases: State

A standard vector-based state, with value represented by a 1D numpy array.

value: ndarray¶

State value

Type:: Any

plus(dx: ndarray) → VectorState¶: A generic “addition” operation given a dx numpy array with as many elements as the dof of this state.

minus(x: VectorState) → ndarray¶: A generic “subtraction” operation given another State object of the same type, always returning a numpy array.

plus_jacobian(dx: ndarray) → ndarray¶

Jacobian of the plus operator. That is, using Lie derivative notation,

\[\mathbf{J} = \frac{D (\mathcal{X} \oplus \delta \mathbf{x})}{D \delta \mathbf{x}}\]

For Lie groups, this is known as the group Jacobian.

minus_jacobian(x: State) → ndarray¶

Jacobian of the minus operator with respect to self.

\[\mathbf{J} = \frac{D (\mathcal{Y} \ominus \mathcal{X})}{D \mathcal{Y}}\]

That is, if dx = y.minus(x) then this is the Jacobian of dx with respect to y. For Lie groups, this is the inverse of the group Jacobian evaluated at dx = x1.minus(x2).

copy() → VectorState¶: Returns a copy of this State instance.

dof¶

Degree of freedom of the state

Type:: int

stamp¶

Timestamp

Type:: float

state_id¶

minus_jacobian_fd(x: State, step_size=1e-08) → ndarray¶: Calculates the minus jacobian with finite difference.

plus_jacobian_fd(dx, step_size=1e-08) → ndarray¶: Calculates the plus jacobian with finite difference.

navlie.lib.states.VectorInput

navlie.bspline