astrix.spatial.rotation module

class RotationLike

Bases: ABC

Abstract base class for rotation objects (RotationSingle, RotationSequence). ‘convert_to’ function is required for integration with other modules.

abstractmethod convert_to(backend)

Return type:

RotationLike

Parameters:

backend (str | Any | None)

abstractmethod interp(time)

Return type:

Rotation

Parameters:

time (Time)

property backend: str

abstract property time: TimeLike

class RotationSequence(rot, time, backend=None)

Bases: RotationLike

A sequence of time-tagged rotations, enabling interpolation between them. Uses scipy.spatial.transform.Slerp for interpolation.

Parameters:

• rot (Rotation | list of Rotation) – A scipy Rotation object containing multiple rotations, or a list of such objects. If a list is provided, all elements must be scipy Rotation objects.

• time (Time) – A Time object with time instances corresponding to each rotation. Must be the same length as the number of rotations and strictly increasing.

• backend (BackendArg, optional) – Array backend to use (numpy, jax, etc.). Defaults to numpy.

Examples

>>> from astrix.primitives import Time, RotationSequence
>>> from scipy.spatial.transform import Rotation
>>> from datetime import datetime, timezone
>>> times = Time.from_datetime(
...     [
...         datetime(2021, 1, 1, 12, 0, 0, tzinfo=timezone.utc),
...         datetime(2021, 1, 1, 13, 0, 0, tzinfo=timezone.utc),
...         datetime(2021, 1, 1, 14, 0, 0, tzinfo=timezone.utc),
...     ]
... )
>>> rots = Rotation.from_euler(
...     "xyz",
...     [
...         [0, 0, 0],
...         [90, 0, 0],
...         [180, 0, 0],
...     ],
...     degrees=True,
... )
>>> rot_seq = RotationSequence(rots, times)

>>> interp_rot = rot_seq.interp(
...     Time.from_datetime(datetime(2021, 1, 1, 12, 30, 0, tzinfo=timezone.utc))
... )  # Interpolate to halfway between first and second rotation
>>> interp_rot.as_euler(
...     "xyz", degrees=True
... )  # Get interpolated rotation as Euler angles
array([[45.,  0.,  0.]])

convert_to(backend)

Convert the RotationSequence object to a different backend.

Return type:

RotationSequence

Parameters:

backend (str | Any | None)

downsample(dt_max)

Downsample the rotation sequence to a coarser time resolution.

Parameters:

dt_max (float) – Desired maximum time step in seconds for downsampling.

Returns:

A new RotationSequence object with downsampled rotations.

Return type:

RotationSequence

interp(time, check_bounds=True)

Interpolate the rotation sequence at the given times to return Rotation(s).

Return type:

Rotation

Parameters:

• time (Time)

• check_bounds (bool)

property rots: Rotation

Get the underlying scipy Rotation object containing all rotations.

property time: Time

Get the Time object associated with the rotation sequence.