Wrench3D

Represents a 3D wrench: a force plus a torque.

Parameters

Field	Type	Description
data	np.ndarray | list | tuple	Array-like input of shape (6,): [fx, fy, fz, tx, ty, tz], converted to a contiguous float32 array.

Raises

Exception	Condition
TypeError	data can't be converted to float32 (e.g. non-numeric elements)
ValueError	data is not rank-1, or its shape isn't (6,)
ValueError	data contains a non-finite value (NaN/Inf)

Attributes

Attribute	Type	Description
data	np.ndarray	Defensive copy of the underlying (6,) float32 array. Assigning a new value re-validates it the same way as construction.
shape	tuple[int, ...]	Always (6,).
ndim	int	Always 1.
dtype	np.dtype	Always float32.
size	int	Always 6.

Methods

Method	Description
to_numpy(copy=True)	Returns the wrench as np.ndarray. Pass copy=False for a reference to the internal array instead — faster, but mutating it mutates the Wrench3D too.
copy()	Returns a new Wrench3D with an independent copy of the data.
Wrench3D.coerce(value)	Returns value unchanged if it's already a Wrench3D; otherwise wraps an array-like into one. Raises TypeError for any other input.

Operators

Operation	Behavior
w == other	True only if other is also a Wrench3D with element-equal data. False for anything else.
len(w)	Always 6.
np.asarray(w)	Works directly via __array__. Always returns a copy; use to_numpy(copy=False) for a zero-copy view.
hash(w)	Not supported — mutable via the data setter.

Visualization

datatypes.visualize(wrench, entity_path=...) logs a static world-origin frame (labeled "origin"), a cyan force arrow labeled "f" from the origin, and a magenta torque arrow labeled "τ" from the origin. Passing label="..." attaches a floating text label at the static origin frame.

Example

"""Demonstrates the Telekinesis Wrench3D datatype."""

import time

import numpy as np
from loguru import logger
import rerun as rr

from telekinesis import datatypes

def wrench3d_example():
    """Demonstrate creation, access, visualization, update, NumPy interop, and serialization."""

    # ======================= Create ============================================
    values = np.array([1.0, 0.0, 0.0, 0.0, 0.0, 0.5], dtype=np.float32)
    wrench3d = datatypes.Wrench3D(values)

    logger.info(f"Input values: {values}")
    logger.info(f"Created Wrench3D: {wrench3d}")

    # ======================= Inspect ===========================================
    data = wrench3d.data
    shape = wrench3d.shape
    size = wrench3d.size
    dtype = wrench3d.dtype
    ndim = wrench3d.ndim
    numpy_array = wrench3d.to_numpy()
    wrench3d_copy = wrench3d.copy()

    logger.info(f"shape={shape}, size={size}, ndim={ndim}, dtype={dtype}")
    logger.info(f"Wrench3D data: {data}")
    logger.info(f"NumPy array: {numpy_array}")
    logger.info(f"Copied Wrench3D: {wrench3d_copy}")

    # ======================= Visualize =========================================
    rr.init("wrench3d_example", spawn=True)
    datatypes.visualize(wrench3d, entity_path="/Wrench3D", label="Original Wrench3D")

    # ======================= Update ============================================
    wrench3d.data = np.array([0.0, 2.0, 0.0, 0.0, 0.0, 1.5], dtype=np.float32)

    logger.info(f"Updated Wrench3D: {wrench3d}")
    datatypes.visualize(wrench3d, entity_path="/Wrench3D/updated", label="Updated Wrench3D")

    # ======================= NumPy Interop =====================================
    force = numpy_array[:3]
    torque = numpy_array[3:]
    force_magnitude = np.linalg.norm(force)
    torque_magnitude = np.linalg.norm(torque)

    logger.info(f"Force (fx, fy, fz): {force}")
    logger.info(f"Torque (tx, ty, tz): {torque}")
    logger.info(f"force_magnitude={force_magnitude}, torque_magnitude={torque_magnitude}")

    # ======================= Serialize / Deserialize ===========================
    start = time.perf_counter()
    serialized = datatypes.serialize(wrench3d)
    serialization_ms = (time.perf_counter() - start) * 1000

    start = time.perf_counter()
    deserialized = datatypes.deserialize(serialized)["param_0"]
    deserialization_ms = (time.perf_counter() - start) * 1000

    logger.info(f"Deserialized Wrench3D: {deserialized}")
    logger.info(f"Round-trip successful: {deserialized == wrench3d}")
    logger.info(f"Serialization time: {serialization_ms:.3f} ms")
    logger.info(f"Deserialization time: {deserialization_ms:.3f} ms")


if __name__ == "__main__":
    wrench3d_example()