InverseKinematics#
- class bayesflow.simulators.InverseKinematics(scales: ndarray = None, l1: float = 0.5, l2: float = 0.5, l3: float = 1.0, rng: Generator = None)[source]#
Bases:
BenchmarkSimulator
Inverse Kinematics simulated benchmark See: https://arxiv.org/pdf/2101.10763.pdf
- Parameters:
- scales: np.ndarray of shape (4, ) or None, optional, default: None
The four scales of the Gaussian prior. If
None
provided, the scales from https://arxiv.org/pdf/2101.10763.pdf will be used: [0.25, 0.5, 0.5, 0.5].- l1: float, optional, default: 0.5
The length of the first segment.
- l2: float, optional, default: 0.5
The length of the second segment.
- l3: float, optional, default: 1.0
The length of the third segment.
- rng: np.random.Generator or None, optional, default: None
An optional random number generator to use.
- prior()[source]#
Generates a random draw from a 4-dimensional Gaussian prior distribution with a spherical convariance matrix. The parameters represent a robot’s arm configuration, with the first parameter indicating the arm’s height and the remaining three are angles.
- Returns:
- paramsnp.ndarray of shape (4, )
A single draw from the 4-dimensional Gaussian prior.
- rejection_sample(batch_shape: tuple[int, ...], predicate: Callable[[dict[str, ndarray]], ndarray], *, axis: int = 0, sample_size: int = None, **kwargs) dict[str, ndarray] #
- sample(batch_shape: tuple[int, ...], **kwargs) dict[str, ndarray] #
Runs simulated benchmark and returns batch_size parameter and observation batches
- Parameters:
- batch_shape: tuple
Number of parameter-observation batches to simulate.
- Returns:
- dict[str, np.ndarray]: simulated parameters and observables
with shapes (batch_size, …)
- sample_batched(batch_shape: tuple[int, ...], *, sample_size: int, **kwargs)#
Sample the desired number of simulations in smaller batches.
Limited resources, especially memory, can make it necessary to run simulations in smaller batches. The number of samples per simulated batch is specified by sample_size.
- observation_model(params: ndarray)[source]#
Returns the 2D coordinates of a robot arm given parameter vector. The first parameter represents the arm’s height and the remaining three correspond to angles.
- Parameters:
- paramsnp.ndarray of shape (params, )
The four model parameters which will determine the coordinates
- Returns:
- xnp.ndarray of shape (2, )
The 2D coordinates of the arm