pytransform3d.transform_manager.TransformGraphBase¶

class pytransform3d.transform_manager.TransformGraphBase(strict_check=True, check=True)[source]¶

Bases: ABC

Base class for all graphs of rigid transformations.

Parameters:

strict_checkbool, optional (default: True): Raise a ValueError if the transformation matrix is not numerically close enough to a real transformation matrix. Otherwise we print a warning.
checkbool, optional (default: True): Check if transformation matrices are valid and requested nodes exist, which might significantly slow down some operations.

__init__(strict_check=True, check=True)[source]¶

Methods

`__init__`([strict_check, check])
`add_transform`(from_frame, to_frame, A2B)	Register a transformation.
`check_consistency`()	Check consistency of the known transformations.
`connected_components`()	Get number of connected components.
`get_transform`(from_frame, to_frame)	Request a transformation.
`has_frame`(frame)	Check if frame has been registered.
`remove_transform`(from_frame, to_frame)	Remove a transformation.

Attributes

transforms

Rigid transformations between nodes.

abstract property transforms¶: Rigid transformations between nodes.

has_frame(frame)[source]¶

Check if frame has been registered.

Parameters:

frameHashable: Frame name

Returns:

has_framebool: Frame is registered

add_transform(from_frame, to_frame, A2B)[source]¶

Parameters:

from_frameHashable: Name of the frame for which the transformation is added in the to_frame coordinate system
to_frameHashable: Name of the frame in which the transformation is defined
A2BAny: Transformation from ‘from_frame’ to ‘to_frame’

Returns:

selfTransformManager: This object for chaining

remove_transform(from_frame, to_frame)[source]¶

Remove a transformation.

Nothing happens if there is no such transformation.

Parameters:

from_frameHashable: Name of the frame for which the transformation is added in the to_frame coordinate system
to_frameHashable: Name of the frame in which the transformation is defined

Returns:

selfTransformManager: This object for chaining

get_transform(from_frame, to_frame)[source]¶

Request a transformation.

Parameters:

from_frameHashable: Name of the frame for which the transformation is requested in the to_frame coordinate system
to_frameHashable: Name of the frame in which the transformation is defined

Returns:

A2BAny: Transformation from ‘from_frame’ to ‘to_frame’

Raises:

KeyError: If one of the frames is unknown or there is no connection between them

connected_components()[source]¶

Get number of connected components.

If the number is larger than 1 there will be frames without connections.

Returns:

n_connected_componentsint: Number of connected components.

check_consistency()[source]¶

Check consistency of the known transformations.

The complexity of this is between $O(n^2)$ and $O(n^3)$ , where $n$ is the number of nodes. In graphs where each pair of nodes is directly connected the complexity is $O(n^2)$ . In graphs that are actually paths, the complexity is $O(n^3)$ .