alibi_detect.cd.pytorch.mmd_online

MMDDriftOnlineTorch

Inherits from: BaseMultiDriftOnline, BaseDetector, StateMixin, ABC

Constructor

MMDDriftOnlineTorch(self, x_ref: Union[numpy.ndarray, list], ert: float, window_size: int, preprocess_fn: Optional[Callable] = None, x_ref_preprocessed: bool = False, kernel: Callable = <class 'alibi_detect.utils.pytorch.kernels.GaussianRBF'>, sigma: Optional[numpy.ndarray] = None, n_bootstraps: int = 1000, device: Union[typing_extensions.Literal['cuda', 'gpu', 'cpu'], ForwardRef('torch.device'), NoneType] = None, verbose: bool = True, input_shape: Optional[tuple] = None, data_type: Optional[str] = None) -> None

Name	Type	Default	Description
x_ref	Union[numpy.ndarray, list]		Data used as reference distribution.
ert	float		The expected run-time (ERT) in the absence of drift. For the multivariate detectors, the ERT is defined as the expected run-time from t=0.
window_size	int		The size of the sliding test-window used to compute the test-statistic. Smaller windows focus on responding quickly to severe drift, larger windows focus on ability to detect slight drift.
preprocess_fn	Optional[Callable]	None	Function to preprocess the data before computing the data drift metrics.
x_ref_preprocessed	bool	False	Whether the given reference data x_ref has been preprocessed yet. If x_ref_preprocessed=True, only the test data x will be preprocessed at prediction time. If x_ref_preprocessed=False, the reference data will also be preprocessed.
kernel	Callable	<class 'alibi_detect.utils.pytorch.kernels.GaussianRBF'>	Kernel used for the MMD computation, defaults to Gaussian RBF kernel.
sigma	Optional[numpy.ndarray]	None	Optionally set the GaussianRBF kernel bandwidth. Can also pass multiple bandwidth values as an array. The kernel evaluation is then averaged over those bandwidths. If sigma is not specified, the 'median heuristic' is adopted whereby sigma is set as the median pairwise distance between reference samples.
n_bootstraps	int	1000	The number of bootstrap simulations used to configure the thresholds. The larger this is the more accurately the desired ERT will be targeted. Should ideally be at least an order of magnitude larger than the ERT.
device	Union[Literal[cuda, gpu, cpu], torch.device, None]	None	Device type used. The default tries to use the GPU and falls back on CPU if needed. Can be specified by passing either 'cuda', 'gpu', 'cpu' or an instance of torch.device. Only relevant for 'pytorch' backend.
verbose	bool	True	Whether or not to print progress during configuration.
input_shape	Optional[tuple]	None	Shape of input data.
data_type	Optional[str]	None	Optionally specify the data type (tabular, image or time-series). Added to metadata.

Methods

score

score(x_t: Union[numpy.ndarray, typing.Any]) -> float

Compute the test-statistic (squared MMD) between the reference window and test window.

Name	Type	Default	Description
x_t	Union[numpy.ndarray, typing.Any]		A single instance to be added to the test-window.

Returns

• Type: float