skactiveml.stream.budgetmanager.SplitBudgetManager

class skactiveml.stream.budgetmanager.SplitBudgetManager(budget=None, w=100, theta=1.0, s=0.01, v=0.1, random_state=None)

Bases: EstimatedBudgetZliobaite

Budget manager which checks, whether the specified budget has been exhausted already. If not, an instance is queried, when the utility is higher than the specified budget. 100*v% of instances will be queried randomly and in 100*(1-v)% of will be queried cases according to VariableUncertainty

This budget manager calculates the estimated budget spent in the last w steps and compares that to the budget. If the ratio is smaller than the specified budget, i.e., budget - u_t / w > 0 , the budget manager samples an instance when its utility is higher than the budget. u is the estimate of how many true lables were queried within the last w steps. The recursive funktion, u_t = u_t-1 * (w-1) / w + labeling_t , is used to calculate u at time t. See also EstimatedBudgetZliobaite

Parameters

budgetfloat, optional (default=None)

Specifies the ratio of instances which are allowed to be queried, with 0 <= budget <= 1. See Also BudgetManager.

wint, optional (default=100)

Specifies the size of the memory window. Controlles the budget in the last w steps taken. Default = 100

thetafloat, optional (default=1.0)

Specifies the starting threshold in wich instances are purchased. This value of theta will recalculated after each instance. Default = 1

sfloat, optional (default=0.01)

Specifies the value in wich theta is decresed or increased based on the purchase of the given label. Default = 0.01

vfloat, optional (default=0.1)

Specifies the percent value of instances queried randomly.

random_stateint | np.random.RandomState, optional (default=None)

Random state for candidate selection.

See also

EstimatedBudgetZliobaite

BudgetManager implementing the base class for Zliobaite based budget managers

Methods

get_metadata_routing()	Get metadata routing of this object.
get_params([deep])	Get parameters for this estimator.
query_by_utility(utilities)	Ask the budget manager which utilities are sufficient to query the corresponding instance.
set_params(**params)	Set the parameters of this estimator.
update(candidates, queried_indices)	Updates the budget manager.

get_metadata_routing()

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns

routingMetadataRequest

A MetadataRequest encapsulating routing information.

get_params(deep=True)

Get parameters for this estimator.

Parameters

deepbool, default=True

If True, will return the parameters for this estimator and contained subobjects that are estimators.

Returns

paramsdict

Parameter names mapped to their values.

query_by_utility(utilities)

Ask the budget manager which utilities are sufficient to query the corresponding instance.

Parameters

utilitiesndarray of shape (n_samples,)

The utilities provided by the stream-based active learning strategy, which are used to determine whether sampling an instance is worth it given the budgeting constraint.

Returns

queried_indicesndarray of shape (n_queried_instances,)

The indices of instances represented by utilities which should be queried, with 0 <= n_queried_instances <= n_samples.

set_params(**params)

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters

**paramsdict

Estimator parameters.

Returns

selfestimator instance

Estimator instance.

update(candidates, queried_indices)

Updates the budget manager.

Parameters

candidates{array-like, sparse matrix} of shape

(n_samples, n_features)

The instances which could be queried. Sparse matrices are accepted only if they are supported by the base query strategy.

queried_indicesarray-like of shape (n_samples,)

Indicates which instances from candidates have been queried.

Returns

selfSplitBudgetManager

The SplitBudget returns itself, after it is updated.