trajectory

Script for analyzing trajectory of a point on optical elements.

correct_rot(src, angle, cent, off=0)

Remove the rotation of an element from a point. For example undo corotation from a point on the LATR.

Parameters:

Name	Type	Description	Default
src	NDArray[float64]	The data to rotate. Should be (npoint, ndim).	required
angle	NDArray[float64]	The angle in degrees of the element at each data point. Should by (npoint,).	required
cent	NDArray[float64]	The center of rotation of the point. Should be (ndim,).	required

Returns:

Name	Type	Description
src	NDArray[float64]	The data with the rotation removed. The input is also modified in place.

Source code in lat_alignment/trajectory.py

def correct_rot(
    src: NDArray[np.float64],
    angle: NDArray[np.float64],
    cent: NDArray[np.float64],
    off: float = 0,
) -> NDArray[np.float64]:
    """
    Remove the rotation of an element from a point.
    For example undo corotation from a point on the LATR.

    Parameters
    ----------
    src : NDArray[np.float64]
        The data to rotate.
        Should be `(npoint, ndim)`.
    angle : NDArray[np.float64]
        The angle in degrees of the element at each data point.
        Should by `(npoint,)`.
    cent : NDArray[np.float64]
        The center of rotation of the point.
        Should be `(ndim,)`.

    Returns
    -------
    src : NDArray[np.float64]
        The data with the rotation removed.
        The input is also modified in place.
    """
    for i, (pt, ang) in enumerate(zip(src, angle)):
        rot = Rotation.from_euler("Y", -1 * (ang - off), degrees=True)
        src[i] = rot.apply(pt - cent) + rot.apply(cent)
    return src

get_angle(data, mode, start, sep, logger)

Reconstruct the angle of an opitcal element from data of a point.

Parameters:

Name	Type	Description	Default
data	NDArray[float64]	A (npoint, ndim) array describing the motion of a point.	required
mode	str	The mode this data was taken in. Should be continious or step.	required
start	float	The angle of the element at the first data point. Should be in degrees.	required
sep	float	The seperation between measurements. If we are in continious mode this should be in mm. If we are in step mode this should be in deg.	required
logger	Logger	The logger object to use.	required

Returns:

Name	Type	Description
angle	NDArray[float64]	The reconstructed angle in degrees. Will be a (npoint,) array.
center	NDArray[float64]	The center of rotation.

Source code in lat_alignment/trajectory.py

def get_angle(
    data: NDArray[np.float64],
    mode: str,
    start: float,
    sep: float,
    logger: logging.Logger,
) -> tuple[NDArray[np.float64], NDArray[np.float64]]:
    """
    Reconstruct the angle of an opitcal element from data of a point.

    Parameters
    ----------
    data : NDArray[np.float64]
        A `(npoint, ndim)` array describing the motion of a point.
    mode : str
        The mode this data was taken in.
        Should be `continious` or `step`.
    start : float
        The angle of the element at the first data point.
        Should be in degrees.
    sep : float
        The seperation between measurements.
        If we are in `continious` mode this should be in mm.
        If we are in `step` mode this should be in deg.
    logger : logging.Logger
        The logger object to use.

    Returns
    -------
    angle : NDArray[np.float64]
        The reconstructed angle in degrees.
        Will be a `(npoint,)` array.
    center : NDArray[np.float64]
        The center of rotation.
    """
    logger.info(
        "\tReconstructing angle in %s mode using a start of %f deg and a seperation of %f",
        mode,
        start,
        sep,
    )
    # Recover the angle
    theta, sphere = _get_sphere_and_angle(data, start, logger)

    # Convert delta to an angle delta
    if mode == "continious":
        logger.warning(
            "\t\tReconstructing angle from continious data, this is approximate and should not be used for pointing corrections! Trajectory Errors will also only be approximate!"
        )
        dtheta = np.rad2deg(sep / sphere.radius) / 32.0
    elif mode == "step":
        dtheta = sep
    else:
        raise ValueError(f"Invalid mode: {mode}")

    # Quantize
    theta_corr = _quantize_angle(theta, dtheta, start)

    return theta_corr, np.array(sphere.point, np.float64)