Package mdp :: Package nodes :: Class BernoulliNBScikitsLearnNode
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Class BernoulliNBScikitsLearnNode



Naive Bayes classifier for multivariate Bernoulli models.

This node has been automatically generated by wrapping the ``sklearn.naive_bayes.BernoulliNB`` class
from the ``sklearn`` library.  The wrapped instance can be accessed
through the ``scikits_alg`` attribute.

Like MultinomialNB, this classifier is suitable for discrete data. The
difference is that while MultinomialNB works with occurrence counts,
BernoulliNB is designed for binary/boolean features.

Read more in the :ref:`User Guide <bernoulli_naive_bayes>`.

**Parameters**

alpha : float, optional (default=1.0)
    Additive (Laplace/Lidstone) smoothing parameter
    (0 for no smoothing).

binarize : float or None, optional
    Threshold for binarizing (mapping to booleans) of sample features.
    If None, input is presumed to already consist of binary vectors.

fit_prior : boolean
    Whether to learn class prior probabilities or not.
    If false, a uniform prior will be used.

class_prior : array-like, size=[n_classes,]
    Prior probabilities of the classes. If specified the priors are not
    adjusted according to the data.

**Attributes**

``class_log_prior_`` : array, shape = [n_classes]
    Log probability of each class (smoothed).

``feature_log_prob_`` : array, shape = [n_classes, n_features]
    Empirical log probability of features given a class, P(x_i|y).

``class_count_`` : array, shape = [n_classes]
    Number of samples encountered for each class during fitting. This
    value is weighted by the sample weight when provided.

``feature_count_`` : array, shape = [n_classes, n_features]
    Number of samples encountered for each (class, feature)
    during fitting. This value is weighted by the sample weight when
    provided.

**Examples**

>>> import numpy as np
>>> X = np.random.randint(2, size=(6, 100))
>>> Y = np.array([1, 2, 3, 4, 4, 5])
>>> from sklearn.naive_bayes import BernoulliNB
>>> clf = BernoulliNB()
>>> clf.fit(X, Y)
BernoulliNB(alpha=1.0, binarize=0.0, class_prior=None, fit_prior=True)
>>> print(clf.predict(X[2:3]))
[3]

**References**


C.D. Manning, P. Raghavan and H. Schuetze (2008). Introduction to
Information Retrieval. Cambridge University Press, pp. 234-265.
http://nlp.stanford.edu/IR-book/html/htmledition/the-bernoulli-model-1.html

A. McCallum and K. Nigam (1998). A comparison of event models for naive
Bayes text classification. Proc. AAAI/ICML-98 Workshop on Learning for
Text Categorization, pp. 41-48.

V. Metsis, I. Androutsopoulos and G. Paliouras (2006). Spam filtering with
naive Bayes -- Which naive Bayes? 3rd Conf. on Email and Anti-Spam (CEAS).

Instance Methods [hide private]
 
__init__(self, input_dim=None, output_dim=None, dtype=None, **kwargs)
Naive Bayes classifier for multivariate Bernoulli models.
 
_get_supported_dtypes(self)
Return the list of dtypes supported by this node. The types can be specified in any format allowed by numpy.dtype.
 
_label(self, x)
 
_stop_training(self, **kwargs)
Transform the data and labels lists to array objects and reshape them.
 
label(self, x)
Perform classification on an array of test vectors X.
 
stop_training(self, **kwargs)
Fit Naive Bayes classifier according to X, y

Inherited from PreserveDimNode (private): _set_input_dim, _set_output_dim

Inherited from unreachable.newobject: __long__, __native__, __nonzero__, __unicode__, next

Inherited from object: __delattr__, __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __subclasshook__

    Inherited from ClassifierCumulator
 
_check_train_args(self, x, labels)
 
_train(self, x, labels)
Cumulate all input data in a one dimensional list.
 
train(self, x, labels)
Cumulate all input data in a one dimensional list.
    Inherited from ClassifierNode
 
_execute(self, x)
 
_prob(self, x, *args, **kargs)
 
execute(self, x)
Process the data contained in x.
 
prob(self, x, *args, **kwargs)
Predict probability for each possible outcome.
 
rank(self, x, threshold=None)
Returns ordered list with all labels ordered according to prob(x) (e.g., [[3 1 2], [2 1 3], ...]).
    Inherited from Node
 
__add__(self, other)
 
__call__(self, x, *args, **kwargs)
Calling an instance of Node is equivalent to calling its execute method.
 
__repr__(self)
repr(x)
 
__str__(self)
str(x)
 
_check_input(self, x)
 
_check_output(self, y)
 
_get_train_seq(self)
 
_if_training_stop_training(self)
 
_inverse(self, x)
 
_pre_execution_checks(self, x)
This method contains all pre-execution checks.
 
_pre_inversion_checks(self, y)
This method contains all pre-inversion checks.
 
_refcast(self, x)
Helper function to cast arrays to the internal dtype.
 
_set_dtype(self, t)
 
copy(self, protocol=None)
Return a deep copy of the node.
 
get_current_train_phase(self)
Return the index of the current training phase.
 
get_dtype(self)
Return dtype.
 
get_input_dim(self)
Return input dimensions.
 
get_output_dim(self)
Return output dimensions.
 
get_remaining_train_phase(self)
Return the number of training phases still to accomplish.
 
get_supported_dtypes(self)
Return dtypes supported by the node as a list of dtype objects.
 
has_multiple_training_phases(self)
Return True if the node has multiple training phases.
 
inverse(self, y, *args, **kwargs)
Invert y.
 
is_training(self)
Return True if the node is in the training phase, False otherwise.
 
save(self, filename, protocol=-1)
Save a pickled serialization of the node to filename. If filename is None, return a string.
 
set_dtype(self, t)
Set internal structures' dtype.
 
set_input_dim(self, n)
Set input dimensions.
 
set_output_dim(self, n)
Set output dimensions.
Static Methods [hide private]
 
is_invertible()
Return True if the node can be inverted, False otherwise.
 
is_trainable()
Return True if the node can be trained, False otherwise.
Properties [hide private]

Inherited from object: __class__

    Inherited from Node
  _train_seq
List of tuples:
  dtype
dtype
  input_dim
Input dimensions
  output_dim
Output dimensions
  supported_dtypes
Supported dtypes
Method Details [hide private]

__init__(self, input_dim=None, output_dim=None, dtype=None, **kwargs)
(Constructor)

 

Naive Bayes classifier for multivariate Bernoulli models.

This node has been automatically generated by wrapping the ``sklearn.naive_bayes.BernoulliNB`` class
from the ``sklearn`` library.  The wrapped instance can be accessed
through the ``scikits_alg`` attribute.

Like MultinomialNB, this classifier is suitable for discrete data. The
difference is that while MultinomialNB works with occurrence counts,
BernoulliNB is designed for binary/boolean features.

Read more in the :ref:`User Guide <bernoulli_naive_bayes>`.

**Parameters**

alpha : float, optional (default=1.0)
    Additive (Laplace/Lidstone) smoothing parameter
    (0 for no smoothing).

binarize : float or None, optional
    Threshold for binarizing (mapping to booleans) of sample features.
    If None, input is presumed to already consist of binary vectors.

fit_prior : boolean
    Whether to learn class prior probabilities or not.
    If false, a uniform prior will be used.

class_prior : array-like, size=[n_classes,]
    Prior probabilities of the classes. If specified the priors are not
    adjusted according to the data.

**Attributes**

``class_log_prior_`` : array, shape = [n_classes]
    Log probability of each class (smoothed).

``feature_log_prob_`` : array, shape = [n_classes, n_features]
    Empirical log probability of features given a class, P(x_i|y).

``class_count_`` : array, shape = [n_classes]
    Number of samples encountered for each class during fitting. This
    value is weighted by the sample weight when provided.

``feature_count_`` : array, shape = [n_classes, n_features]
    Number of samples encountered for each (class, feature)
    during fitting. This value is weighted by the sample weight when
    provided.

**Examples**

>>> import numpy as np
>>> X = np.random.randint(2, size=(6, 100))
>>> Y = np.array([1, 2, 3, 4, 4, 5])
>>> from sklearn.naive_bayes import BernoulliNB
>>> clf = BernoulliNB()
>>> clf.fit(X, Y)
BernoulliNB(alpha=1.0, binarize=0.0, class_prior=None, fit_prior=True)
>>> print(clf.predict(X[2:3]))
[3]

**References**


C.D. Manning, P. Raghavan and H. Schuetze (2008). Introduction to
Information Retrieval. Cambridge University Press, pp. 234-265.
http://nlp.stanford.edu/IR-book/html/htmledition/the-bernoulli-model-1.html

A. McCallum and K. Nigam (1998). A comparison of event models for naive
Bayes text classification. Proc. AAAI/ICML-98 Workshop on Learning for
Text Categorization, pp. 41-48.

V. Metsis, I. Androutsopoulos and G. Paliouras (2006). Spam filtering with
naive Bayes -- Which naive Bayes? 3rd Conf. on Email and Anti-Spam (CEAS).

Overrides: object.__init__

_get_supported_dtypes(self)

 
Return the list of dtypes supported by this node. The types can be specified in any format allowed by numpy.dtype.
Overrides: Node._get_supported_dtypes

_label(self, x)

 
Overrides: ClassifierNode._label

_stop_training(self, **kwargs)

 
Transform the data and labels lists to array objects and reshape them.

Overrides: Node._stop_training

is_invertible()
Static Method

 
Return True if the node can be inverted, False otherwise.
Overrides: Node.is_invertible
(inherited documentation)

is_trainable()
Static Method

 
Return True if the node can be trained, False otherwise.
Overrides: Node.is_trainable

label(self, x)

 

Perform classification on an array of test vectors X.

This node has been automatically generated by wrapping the sklearn.naive_bayes.BernoulliNB class from the sklearn library. The wrapped instance can be accessed through the scikits_alg attribute.

Parameters

X : array-like, shape = [n_samples, n_features]

Returns

C : array, shape = [n_samples]
Predicted target values for X
Overrides: ClassifierNode.label

stop_training(self, **kwargs)

 

Fit Naive Bayes classifier according to X, y

This node has been automatically generated by wrapping the sklearn.naive_bayes.BernoulliNB class from the sklearn library. The wrapped instance can be accessed through the scikits_alg attribute.

Parameters

X : {array-like, sparse matrix}, shape = [n_samples, n_features]
Training vectors, where n_samples is the number of samples and n_features is the number of features.
y : array-like, shape = [n_samples]
Target values.
sample_weight : array-like, shape = [n_samples], optional
Weights applied to individual samples (1. for unweighted).

Returns

self : object
Returns self.
Overrides: Node.stop_training