mvpa2.clfs.meta.CombinedClassifier

class mvpa2.clfs.meta.CombinedClassifier(clfs=None, combiner='auto', **kwargs)

BoostedClassifier which combines predictions using some PredictionsCombiner functor.

Notes

Available conditional attributes:

• calling_time+: None
• estimates+: Internal classifier estimates the most recent predictions are based on
• predicting_time+: Time (in seconds) which took classifier to predict
• predictions+: Most recent set of predictions
• raw_estimates: Estimates obtained from each classifier
• raw_predictions: Predictions obtained from each classifier
• raw_results: None
• trained_dataset: None
• trained_nsamples+: None
• trained_targets+: None
• training_stats: Confusion matrix of learning performance
• training_time+: None

(Conditional attributes enabled by default suffixed with +)

Methods

get_sensitivity_analyzer(**kwargs)	Return an appropriate SensitivityAnalyzer
summary()	Provide summary for the CombinedClassifier.

Initialize the instance.

Parameters:

clfs : list of Classifier

list of classifier instances to use

combiner : PredictionsCombiner, optional

callable which takes care about combining multiple results into a single one. If default (‘auto’) chooses MaximalVote for classification and MeanPrediction for regression. If None is provided – no combination is done

enable_ca : None or list of str

Names of the conditional attributes which should be enabled in addition to the default ones

disable_ca : None or list of str

Names of the conditional attributes which should be disabled

propagate_ca : bool

either to propagate enabled ca into slave classifiers. It is in effect only when slaves get assigned - so if state is enabled not during construction, it would not necessarily propagate into slaves

auto_train : bool

Flag whether the learner will automatically train itself on the input dataset when called untrained.

force_train : bool

Flag whether the learner will enforce training on the input dataset upon every call.

space : str, optional

Name of the ‘processing space’. The actual meaning of this argument heavily depends on the sub-class implementation. In general, this is a trigger that tells the node to compute and store information about the input data that is “interesting” in the context of the corresponding processing in the output dataset.

pass_attr : str, list of str|tuple, optional

Additional attributes to pass on to an output dataset. Attributes can be taken from all three attribute collections of an input dataset (sa, fa, a – see Dataset.get_attr()), or from the collection of conditional attributes (ca) of a node instance. Corresponding collection name prefixes should be used to identify attributes, e.g. ‘ca.null_prob’ for the conditional attribute ‘null_prob’, or ‘fa.stats’ for the feature attribute stats. In addition to a plain attribute identifier it is possible to use a tuple to trigger more complex operations. The first tuple element is the attribute identifier, as described before. The second element is the name of the target attribute collection (sa, fa, or a). The third element is the axis number of a multidimensional array that shall be swapped with the current first axis. The fourth element is a new name that shall be used for an attribute in the output dataset. Example: (‘ca.null_prob’, ‘fa’, 1, ‘pvalues’) will take the conditional attribute ‘null_prob’ and store it as a feature attribute ‘pvalues’, while swapping the first and second axes. Simplified instructions can be given by leaving out consecutive tuple elements starting from the end.

postproc : Node instance, optional

Node to perform post-processing of results. This node is applied in __call__() to perform a final processing step on the to be result dataset. If None, nothing is done.

descr : str

Description of the instance

NB: `combiner` might need to operate not on ‘predictions’ discrete :

labels but rather on raw ‘class’ estimates classifiers estimate (which is pretty much what is stored under estimates)

Methods

get_sensitivity_analyzer(**kwargs)	Return an appropriate SensitivityAnalyzer
summary()	Provide summary for the CombinedClassifier.

combiner

summary()

Provide summary for the CombinedClassifier.