mvpa2.clfs.warehouse.MulticlassClassifier

Inheritance diagram of MulticlassClassifier

class mvpa2.clfs.warehouse.MulticlassClassifier(clf, bclf_type='1-vs-1', **kwargs)

CombinedClassifier to perform multiclass using a list of BinaryClassifier.

such as 1-vs-1 (ie in pairs like libsvm doesn) or 1-vs-all (which is yet to think about)

Notes

Available conditional attributes:

  • calling_time+: Time (in seconds) it took to call the node
  • 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: Computed results before invoking postproc. Stored only if postproc is not None.
  • trained_dataset: The dataset it has been trained on
  • trained_nsamples+: Number of samples it has been trained on
  • trained_targets+: Set of unique targets it has been trained on
  • training_stats: Confusion matrix of learning performance
  • training_time+: Time (in seconds) it took to train the learner

(Conditional attributes enabled by default suffixed with +)

Methods

clone() Create full copy of the classifier.
generate(ds) Yield processing results.
get_postproc() Returns the post-processing node or None.
get_sensitivity_analyzer(**kwargs) Return an appropriate SensitivityAnalyzer
get_space() Query the processing space name of this node.
is_trained([dataset]) Either classifier was already trained.
predict(obj, data, *args, **kwargs)
repredict(obj, data, *args, **kwargs)
reset()
retrain(dataset, **kwargs) Helper to avoid check if data was changed actually changed Useful if just some aspects of classifier were changed since its previous training.
set_postproc(node) Assigns a post-processing node Set to None to disable postprocessing.
set_space(name) Set the processing space name of this node.
summary() Provide summary for the CombinedClassifier.
train(ds) The default implementation calls _pretrain(), _train(), and finally _posttrain().
untrain() Reverts changes in the state of this node caused by previous training

Initialize the instance

Parameters:

clf : Classifier

classifier based on which multiple classifiers are created for multiclass

bclf_type :

“1-vs-1” or “1-vs-all”, determines the way to generate binary classifiers

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

clfs : list of Classifier

list of classifier instances to use

combiner : PredictionsCombiner

callable which takes care about combining multiple results into a single one (e.g. maximal vote for classification, MeanPrediction for regression))

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.

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

Methods

clone() Create full copy of the classifier.
generate(ds) Yield processing results.
get_postproc() Returns the post-processing node or None.
get_sensitivity_analyzer(**kwargs) Return an appropriate SensitivityAnalyzer
get_space() Query the processing space name of this node.
is_trained([dataset]) Either classifier was already trained.
predict(obj, data, *args, **kwargs)
repredict(obj, data, *args, **kwargs)
reset()
retrain(dataset, **kwargs) Helper to avoid check if data was changed actually changed Useful if just some aspects of classifier were changed since its previous training.
set_postproc(node) Assigns a post-processing node Set to None to disable postprocessing.
set_space(name) Set the processing space name of this node.
summary() Provide summary for the CombinedClassifier.
train(ds) The default implementation calls _pretrain(), _train(), and finally _posttrain().
untrain() Reverts changes in the state of this node caused by previous training

NeuroDebian

NITRC-listed