Linear Support Vector Regression.
Similar to SVR with parameter kernel='linear', but implemented in terms of liblinear rather than libsvm, so it has more flexibility in the choice of penalties and loss functions and should scale better to large numbers of samples.
This class supports both dense and sparse input.
Read more in the :ref:`User Guide <svm_regression>`.
.. versionadded:: 0.16
Parameters ---------- epsilon : float, default=0.0 Epsilon parameter in the epsilon-insensitive loss function. Note that the value of this parameter depends on the scale of the target variable y. If unsure, set ``epsilon=0``.
tol : float, default=1e-4 Tolerance for stopping criteria.
C : float, default=1.0 Regularization parameter. The strength of the regularization is inversely proportional to C. Must be strictly positive.
loss : 'epsilon_insensitive', 'squared_epsilon_insensitive'
, default='epsilon_insensitive' Specifies the loss function. The epsilon-insensitive loss (standard SVR) is the L1 loss, while the squared epsilon-insensitive loss ('squared_epsilon_insensitive') is the L2 loss.
fit_intercept : bool, default=True Whether to calculate the intercept for this model. If set to false, no intercept will be used in calculations (i.e. data is expected to be already centered).
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.
dual : bool, default=True Select the algorithm to either solve the dual or primal optimization problem. Prefer dual=False when n_samples > n_features.
verbose : int, default=0 Enable verbose output. Note that this setting takes advantage of a per-process runtime setting in liblinear that, if enabled, may not work properly in a multithreaded context.
random_state : int or RandomState instance, default=None Controls the pseudo random number generation for shuffling the data. Pass an int for reproducible output across multiple function calls. See :term:`Glossary <random_state>`.
max_iter : int, default=1000 The maximum number of iterations to be run.
Attributes ---------- coef_ : ndarray of shape (n_features) if n_classes == 2 else (n_classes, n_features) Weights assigned to the features (coefficients in the primal problem). This is only available in the case of a linear kernel.
`coef_` is a readonly property derived from `raw_coef_` that follows the internal memory layout of liblinear.
intercept_ : ndarray of shape (1) if n_classes == 2 else (n_classes) Constants in decision function.
n_iter_ : int Maximum number of iterations run across all classes.
Examples -------- >>> from sklearn.svm import LinearSVR >>> from sklearn.pipeline import make_pipeline >>> from sklearn.preprocessing import StandardScaler >>> from sklearn.datasets import make_regression >>> X, y = make_regression(n_features=4, random_state=0) >>> regr = make_pipeline(StandardScaler(), ... LinearSVR(random_state=0, tol=1e-5)) >>> regr.fit(X, y) Pipeline(steps=('standardscaler', StandardScaler()),
('linearsvr', LinearSVR(random_state=0, tol=1e-05))
)
>>> print(regr.named_steps'linearsvr'
.coef_) 18.582... 27.023... 44.357... 64.522...
>>> print(regr.named_steps'linearsvr'
.intercept_) -4...
>>> print(regr.predict([0, 0, 0, 0]
)) -2.384...
See also -------- LinearSVC Implementation of Support Vector Machine classifier using the same library as this class (liblinear).
SVR Implementation of Support Vector Machine regression using libsvm: the kernel can be non-linear but its SMO algorithm does not scale to large number of samples as LinearSVC does.
sklearn.linear_model.SGDRegressor SGDRegressor can optimize the same cost function as LinearSVR by adjusting the penalty and loss parameters. In addition it requires less memory, allows incremental (online) learning, and implements various loss functions and regularization regimes.