scikit-learn/sklearn/svm/sparse/classes.py

243 lines
7.9 KiB
Python

from ...base import ClassifierMixin, RegressorMixin
from .base import SparseBaseLibSVM, SparseBaseLibLinear
from ...linear_model.sparse.base import CoefSelectTransformerMixin
class SVC(SparseBaseLibSVM, ClassifierMixin):
"""SVC for sparse matrices (csr).
See :class:`sklearn.svm.SVC` for a complete list of parameters
Notes
-----
For best results, this accepts a matrix in csr format
(scipy.sparse.csr), but should be able to convert from any array-like
object (including other sparse representations).
Examples
--------
>>> import numpy as np
>>> X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
>>> y = np.array([1, 1, 2, 2])
>>> from sklearn.svm.sparse import SVC
>>> clf = SVC()
>>> clf.fit(X, y)
SVC(C=1.0, coef0=0.0, degree=3, gamma=0.25, kernel='rbf', probability=False,
shrinking=True, tol=0.001)
>>> print clf.predict([[-0.8, -1]])
[ 1.]
"""
def __init__(self, C=1.0, kernel='rbf', degree=3, gamma=0.0,
coef0=0.0, shrinking=True, probability=False,
tol=1e-3):
SparseBaseLibSVM.__init__(self, 'c_svc', kernel, degree, gamma, coef0,
tol, C, 0., 0.,
shrinking, probability)
class NuSVC (SparseBaseLibSVM, ClassifierMixin):
"""NuSVC for sparse matrices (csr).
See :class:`sklearn.svm.NuSVC` for a complete list of parameters
Notes
-----
For best results, this accepts a matrix in csr format
(scipy.sparse.csr), but should be able to convert from any array-like
object (including other sparse representations).
Examples
--------
>>> import numpy as np
>>> X = np.array([[-1, -1], [-2, -1], [1, 1], [2, 1]])
>>> y = np.array([1, 1, 2, 2])
>>> from sklearn.svm.sparse import NuSVC
>>> clf = NuSVC()
>>> clf.fit(X, y)
NuSVC(coef0=0.0, degree=3, gamma=0.25, kernel='rbf', nu=0.5,
probability=False, shrinking=True, tol=0.001)
>>> print clf.predict([[-0.8, -1]])
[ 1.]
"""
def __init__(self, nu=0.5, kernel='rbf', degree=3, gamma=0.0,
coef0=0.0, shrinking=True, probability=False,
tol=1e-3):
SparseBaseLibSVM.__init__(self, 'nu_svc', kernel, degree,
gamma, coef0, tol, 0., nu, 0.,
shrinking, probability)
class SVR (SparseBaseLibSVM, RegressorMixin):
"""SVR for sparse matrices (csr)
See :class:`sklearn.svm.SVR` for a complete list of parameters
Notes
-----
For best results, this accepts a matrix in csr format
(scipy.sparse.csr), but should be able to convert from any array-like
object (including other sparse representations).
Examples
--------
>>> from sklearn.svm.sparse import SVR
>>> import numpy as np
>>> n_samples, n_features = 10, 5
>>> np.random.seed(0)
>>> y = np.random.randn(n_samples)
>>> X = np.random.randn(n_samples, n_features)
>>> clf = SVR(C=1.0, epsilon=0.2)
>>> clf.fit(X, y)
SVR(C=1.0, coef0=0.0, degree=3, epsilon=0.2, gamma=0.1, kernel='rbf', nu=0.5,
probability=False, shrinking=True, tol=0.001)
"""
def __init__(self, kernel='rbf', degree=3, gamma=0.0, coef0=0.0,
tol=1e-3, C=1.0, nu=0.5, epsilon=0.1,
shrinking=True, probability=False):
SparseBaseLibSVM.__init__(self, 'epsilon_svr', kernel,
degree, gamma, coef0, tol, C, nu,
epsilon, shrinking, probability)
class NuSVR (SparseBaseLibSVM, RegressorMixin):
"""NuSVR for sparse matrices (csr)
See :class:`sklearn.svm.NuSVC` for a complete list of parameters
Notes
-----
For best results, this accepts a matrix in csr format
(scipy.sparse.csr), but should be able to convert from any array-like
object (including other sparse representations).
Examples
--------
>>> from sklearn.svm.sparse import NuSVR
>>> import numpy as np
>>> n_samples, n_features = 10, 5
>>> np.random.seed(0)
>>> y = np.random.randn(n_samples)
>>> X = np.random.randn(n_samples, n_features)
>>> clf = NuSVR(nu=0.1, C=1.0)
>>> clf.fit(X, y)
NuSVR(C=1.0, coef0=0.0, degree=3, epsilon=0.1, gamma=0.1, kernel='rbf',
nu=0.1, probability=False, shrinking=True, tol=0.001)
"""
def __init__(self, nu=0.5, C=1.0, kernel='rbf', degree=3,
gamma=0.0, coef0=0.0, shrinking=True, epsilon=0.1,
probability=False, tol=1e-3):
SparseBaseLibSVM.__init__(self, 'nu_svr', kernel,
degree, gamma, coef0, tol, C, nu,
epsilon, shrinking, probability)
class OneClassSVM (SparseBaseLibSVM):
"""NuSVR for sparse matrices (csr)
See :class:`sklearn.svm.NuSVC` for a complete list of parameters
Notes
-----
For best results, this accepts a matrix in csr format
(scipy.sparse.csr), but should be able to convert from any array-like
object (including other sparse representations).
"""
def __init__(self, kernel='rbf', degree=3, gamma=0.0, coef0=0.0,
tol=1e-3, nu=0.5, shrinking=True,
probability=False):
SparseBaseLibSVM.__init__(self, 'one_class', kernel, degree,
gamma, coef0, tol, 0.0, nu, 0.0,
shrinking, probability)
def fit(self, X, class_weight={}, sample_weight=[]):
super(OneClassSVM, self).fit(
X, [], class_weight=class_weight, ample_weight=sample_weight)
class LinearSVC(SparseBaseLibLinear, ClassifierMixin,
CoefSelectTransformerMixin):
"""
Linear Support Vector Classification, Sparse Version
Similar to SVC with parameter kernel='linear', but uses internally
liblinear rather than libsvm, so it has more flexibility in the
choice of penalties and loss functions and should be faster for
huge datasets.
Parameters
----------
loss : string, 'l1' or 'l2' (default 'l2')
Specifies the loss function. With 'l1' it is the standard SVM
loss (a.k.a. hinge Loss) while with 'l2' it is the squared loss.
(a.k.a. squared hinge Loss)
penalty : string, 'l1' or 'l2' (default 'l2')
Specifies the norm used in the penalization. The 'l2' penalty
is the standard used in SVC. The 'l1' leads to ``coef_``
vectors that are sparse.
C : float, optional (default=1.0)
penalty parameter C of the error term.
dual : bool, (default True)
Select the algorithm to either solve the dual or primal
optimization problem.
intercept_scaling : float, default: 1
when self.fit_intercept is True, instance vector x becomes
[x, self.intercept_scaling],
i.e. a "synthetic" feature with constant value equals to
intercept_scaling is appended to the instance vector.
The intercept becomes intercept_scaling * synthetic feature weight
Note! the synthetic feature weight is subject to l1/l2 regularization
as all other features.
To lessen the effect of regularization on synthetic feature weight
(and therefore on the intercept) intercept_scaling has to be increased
Attributes
----------
`coef_` : array, shape = [n_features] if n_classes == 2 else [n_classes, n_features]
Wiehgiths asigned to the features (coefficients in the primal
problem). This is only available in the case of linear kernel.
`intercept_` : array, shape = [1] if n_classes == 2 else [n_classes]
constants in decision function
Notes
-----
The underlying C implementation uses a random number generator to
select features when fitting the model. It is thus not uncommon,
to have slightly different results for the same input data. If
that happens, try with a smaller eps parameter.
See also
--------
SVC
References
----------
LIBLINEAR -- A Library for Large Linear Classification
http://www.csie.ntu.edu.tw/~cjlin/liblinear/
"""
pass