embdata 0.0.2

Data, types, pipes, manipulation for embodied learning.

mbodied-data

---

Table of Contents

• mbodied-data
  • Table of Contents
  • Installation
  • Classes
    • Coordinate
      • Pose
    • Episode
    • Exploratory data analysis for common minmax and standardization normalization methods.
    • Upsample and downsample the trajectory to a target frequency.
    • Make actions relative or absolute
  • Applications
    • What are the grasping positions in the world frame?
  • License
  • Design Decisions

Installation

pip install embdata

Classes

Coordinate

Classes for representing geometric data in cartesian and polar coordinates.

Pose

• (x, y, z, roll, pitch, and yaw) in some reference frame.
• Contains .numpy(), .dict(), .dataset() methods from Sample class we all know and love.

Example:

    >>> import math
    >>> pose_3d = Pose3D(x=1, y=2, theta=math.pi/2)
    >>> pose_3d.to("cm")
    Pose3D(x=100.0, y=200.0, theta=1.5707963267948966)

    >>> pose_3d.to("deg")
    Pose3D(x=1.0, y=2.0, theta=90.0)

    >>> class BoundedPose6D(Pose6D):
    ...     x: float = CoordinateField(bounds=(0, 5))

    >>> pose_6d = BoundedPose6D(x=10, y=2, z=3, roll=0, pitch=0, yaw=0)
    Traceback (most recent call last):
    ...
    ValueError: x value 10 is not within bounds (0, 5)

Episode

The Episode class provides a list-like interface for a sequence of observations, actions, and/or other data points. It is designed to streamline exploratory data analysis and manipulation of time series data. Episodes can be easily concatenated, iterated over, and manipulated similar to lists.

class Episode(Sample):
    """A list-like interface for a sequence of observations, actions, and/or other.

    Meant to streamline exploratory data analysis and manipulation of time series data.

    Just append to an episode like you would a list and you're ready to start training models.

    To iterate over the steps in an episode, use the `iter` method.

Example:

    >>> episode = Episode(steps=[TimeStep(), TimeStep(), TimeStep()])
    >>> for step in episode.iter():
    ...     print(step)

To concatenate two episodes, use the + operator.

Example:

    >>> episode1 = Episode(steps=[TimeStep(), TimeStep()])
    >>> episode2 = Episode(steps=[TimeStep(), TimeStep()])
    >>> combined_episode = episode1 + episode2
    >>> len(combined_episode)
    4 

 def from_list(cls, steps: List[Dict|Sample], observation_key:str, action_key: str, supervision_key:str = None) -> 'Episode':
        """Create an episode from a list of dictionaries.

        Args:
            steps (List[Dict|Sample]): The list of dictionaries representing the steps.
            action_key (str): The key for the action in each dictionary.
            observation_key (str): The key for the observation in each dictionary.
            supervision_key (str, optional): The key for the supervision in each dictionary. Defaults to None.

        Returns:
            'Episode': The created episode.

Example:

    >>> steps = [
    ...     {"observation": Image((224,224)), "action": Sample(1), "supervision": 0},
    ...     {"observation": Image((224,224)), "action": Sample(1), "supervision": 1},
    ...     {"observation": Image((224,224)), "action": Sample(100), "supervision": 0},
    ...     {"observation": Image((224,224)), "action": Sample(300), "supervision": 1},
    ... ]
    >>> episode = Episode.from_list(steps, "observation", "action", "supervision")
    >>> episode
    Episode(
        Stats(
            mean=[100.5]
            variance=[19867.0]
            skewness=[0.821]
            kurtosis=[-0.996]
            min=[1]
            max=[300]
            lower_quartile=[1.0]
            median=[50.5]
            upper_quartile=[150.0]
            non_zero_count=[4]
            zero_count=[0])
    )

Exploratory data analysis for common minmax and standardization normalization methods.

Example

    >>> steps = [
    ...     {"observation": Image((224,224)), "action": 1, "supervision": 0},
    ...     {"observation": Image((224,224)), "action": 1, "supervision": 1},
    ...     {"observation": Image((224,224)), "action": 100, "supervision": 0},
    ...     {"observation": Image((224,224)), "action": 300, "supervision": 1},
    ]
    >>> episode = Episode.from_list(steps, "observation", "action", "supervision")
    >>> episode.trajectory().transform("minmax")
    Episode(
        Stats(
            mean=[0.335]
            variance=[0.198]
            skewness=[0.821]
            kurtosis=[-0.996]
            min=[0.0]
            max=[1.0]
            lower_quartile=[0.0]
            median=[0.168]
            upper_quartile=[0.503]
            non_zero_count=[4]
            zero_count=[0])
    )
    >>> episode.trajectory().transform("standard")
    Episode(
        Stats(
            mean=[0.335]
            variance=[0.198]
            skewness=[0.821]
            kurtosis=[-0.996]
            min=[-1.0]
            max=[1.0]
            lower_quartile=[-1.0]
            median=[0.0]
            upper_quartile=[1.0]
            non_zero_count=[4]
            zero_count=[0])
    )
    >>> episode.trajectory().transform("unstandard", mean=0.335, std=0.198)
    Episode(
        Stats(
            mean=[100.5]
            variance=[19867.0]
            skewness=[0.821]
            kurtosis=[-0.996]
            min=[1]
            max=[300]
            lower_quartile=[1.0]
            median=[50.5]
            upper_quartile=[150.0]
            non_zero_count=[4]
            zero_count=[0])
    )
    >>> episode.trajectory().frequencies().show()  # .save("path/to/save.png") also works.
    >>> episode.trajectory().plot().show()

Upsample and downsample the trajectory to a target frequency.

• Uses bicupic and rotation spline interpolation to upsample and downsample the trajectory to a target frequency.

    >>> episode.trajectory().resample(target_hz=10).plot().show() # .save("path/to/save.png") also works.

Make actions relative or absolute

• Make actions relative or absolute to the previous action.

    >>> relative_actions = episode.trajectory("action").make_relative()
    >>>  absolute_again = episode.trajectory().make_absolute(initial_state=relative_actions[0])
    assert np.allclose(episode.trajectory("action"), absolute_again)

Applications

What are the grasping positions in the world frame?

    >>> initial_state = episode.trajectory('state').flatten(to='end_effector_pose')[0]
    >>> episode.trajectory('action').make_absolute(initial_state=initial_state).filter(lambda x: x.grasp == 1)

License

embdata is distributed under the terms of the apache-2.0 license.

Design Decisions

• Grasp value is [-1, 1] so that the default value is 0.
• Motion rather than Action to distinguish from non-physical actions.