mvpa2.clfs.warehouse.LinearNuSVMC

class mvpa2.clfs.warehouse.LinearNuSVMC(nu=0.5, **kwargs)

Nu-SVM classifier using linear kernel.

See documentation of AttributesCollector for more information

Attributes

auto_train	Whether the Learner performs automatic trainingwhen called untrained.
descr	Description of the object if any
force_train	Whether the Learner enforces training upon every call.
kernel_params
model
pass_attr	Which attributes of the dataset or self.ca to pass into result dataset upon call
postproc	Node to perform post-processing of results
space	Processing space name of this node
trained	Either classifier was already trained

Methods

__call__(ds)
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)	Returns 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
set_postproc(node)	Assigns a post-processing node
set_space(name)	Set the processing space name of this node.
summary()	Provide quick summary over the SVM classifier
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 instance of LinearNuSVMC

Parameters:

kernel

Kernel object. [Default: None]

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

tube_epsilon

Epsilon in epsilon-insensitive loss function of epsilon-SVM regression (SVR). [Default: 0.01]

C

Trade-off parameter between width of the margin and number of support vectors. Higher C – more rigid margin SVM. In linear kernel, negative values provide automatic scaling of their value according to the norm of the data. [Default: -1.0]

weight : list(float), optional

Custom weights per label. Constraints: value must be convertible to list(float). [Default: []]

probability

Flag to signal either probability estimate is obtained within LIBSVM. [Default: 0]

epsilon

Tolerance of termination criteria. (For nu-SVM default is 0.001). [Default: 5e-05]

weight_label : list(int), optional

To be used in conjunction with weight for custom per-label weight. Constraints: value must be convertible to list(int). [Default: []]

shrinking

Either shrinking is to be conducted. [Default: 1]

nu

Fraction of datapoints within the margin. [Default: 0.5]

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

Attributes

auto_train	Whether the Learner performs automatic trainingwhen called untrained.
descr	Description of the object if any
force_train	Whether the Learner enforces training upon every call.
kernel_params
model
pass_attr	Which attributes of the dataset or self.ca to pass into result dataset upon call
postproc	Node to perform post-processing of results
space	Processing space name of this node
trained	Either classifier was already trained

Methods

__call__(ds)
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)	Returns 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
set_postproc(node)	Assigns a post-processing node
set_space(name)	Set the processing space name of this node.
summary()	Provide quick summary over the SVM classifier
train(ds)	The default implementation calls _pretrain(), _train(), and finally _posttrain().
untrain()	Reverts changes in the state of this node caused by previous training