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Linear model fitted by minimizing a regularized empirical loss with SGD This node has been automatically generated by wrapping the ``sklearn.linear_model.stochastic_gradient.SGDRegressor`` class from the ``sklearn`` library. The wrapped instance can be accessed through the ``scikits_alg`` attribute. SGD stands for Stochastic Gradient Descent: the gradient of the loss is estimated each sample at a time and the model is updated along the way with a decreasing strength schedule (aka learning rate). The regularizer is a penalty added to the loss function that shrinks model parameters towards the zero vector using either the squared euclidean norm L2 or the absolute norm L1 or a combination of both (Elastic Net). If the parameter update crosses the 0.0 value because of the regularizer, the update is truncated to 0.0 to allow for learning sparse models and achieve online feature selection. This implementation works with data represented as dense numpy arrays of floating point values for the features. Read more in the :ref:`User Guide <sgd>`. **Parameters** loss : str, 'squared_loss', 'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive' The loss function to be used. Defaults to 'squared_loss' which refers to the ordinary least squares fit. 'huber' modifies 'squared_loss' to focus less on getting outliers correct by switching from squared to linear loss past a distance of epsilon. 'epsilon_insensitive' ignores errors less than epsilon and is linear past that; this is the loss function used in SVR. 'squared_epsilon_insensitive' is the same but becomes squared loss past a tolerance of epsilon. penalty : str, 'none', 'l2', 'l1', or 'elasticnet' The penalty (aka regularization term) to be used. Defaults to 'l2' which is the standard regularizer for linear SVM models. 'l1' and 'elasticnet' might bring sparsity to the model (feature selection) not achievable with 'l2'. alpha : float Constant that multiplies the regularization term. Defaults to 0.0001 Also used to compute learning_rate when set to 'optimal'. l1_ratio : float The Elastic Net mixing parameter, with 0 <= l1_ratio <= 1. l1_ratio=0 corresponds to L2 penalty, l1_ratio=1 to L1. Defaults to 0.15. fit_intercept : bool Whether the intercept should be estimated or not. If False, the data is assumed to be already centered. Defaults to True. n_iter : int, optional The number of passes over the training data (aka epochs). The number of iterations is set to 1 if using partial_fit. Defaults to 5. shuffle : bool, optional Whether or not the training data should be shuffled after each epoch. Defaults to True. random_state : int seed, RandomState instance, or None (default) The seed of the pseudo random number generator to use when shuffling the data. verbose : integer, optional The verbosity level. epsilon : float Epsilon in the epsiloninsensitive loss functions; only if `loss` is 'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'. For 'huber', determines the threshold at which it becomes less important to get the prediction exactly right. For epsiloninsensitive, any differences between the current prediction and the correct label are ignored if they are less than this threshold. learning_rate : string, optional The learning rate:  constant: eta = eta0  optimal: eta = 1.0/(alpha * t)  invscaling: eta = eta0 / pow(t, power_t) [default] eta0 : double, optional The initial learning rate [default 0.01]. power_t : double, optional The exponent for inverse scaling learning rate [default 0.25]. warm_start : bool, optional When set to True, reuse the solution of the previous call to fit as initialization, otherwise, just erase the previous solution. average : bool or int, optional When set to True, computes the averaged SGD weights and stores the result in the ``coef_`` attribute. If set to an int greater than 1, averaging will begin once the total number of samples seen reaches average. So ``average=10 will`` begin averaging after seeing 10 samples. **Attributes** ``coef_`` : array, shape (n_features,) Weights assigned to the features. ``intercept_`` : array, shape (1,) The intercept term. ``average_coef_`` : array, shape (n_features,) Averaged weights assigned to the features. ``average_intercept_`` : array, shape (1,) The averaged intercept term. **Examples** >>> import numpy as np >>> from sklearn import linear_model >>> 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 = linear_model.SGDRegressor() >>> clf.fit(X, y) ... #doctest: +NORMALIZE_WHITESPACE SGDRegressor(alpha=0.0001, average=False, epsilon=0.1, eta0=0.01, fit_intercept=True, l1_ratio=0.15, learning_rate='invscaling', loss='squared_loss', n_iter=5, penalty='l2', power_t=0.25, random_state=None, shuffle=True, verbose=0, warm_start=False) See also Ridge, ElasticNet, Lasso, SVR














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supported_dtypes Supported dtypes 

Linear model fitted by minimizing a regularized empirical loss with SGD This node has been automatically generated by wrapping the ``sklearn.linear_model.stochastic_gradient.SGDRegressor`` class from the ``sklearn`` library. The wrapped instance can be accessed through the ``scikits_alg`` attribute. SGD stands for Stochastic Gradient Descent: the gradient of the loss is estimated each sample at a time and the model is updated along the way with a decreasing strength schedule (aka learning rate). The regularizer is a penalty added to the loss function that shrinks model parameters towards the zero vector using either the squared euclidean norm L2 or the absolute norm L1 or a combination of both (Elastic Net). If the parameter update crosses the 0.0 value because of the regularizer, the update is truncated to 0.0 to allow for learning sparse models and achieve online feature selection. This implementation works with data represented as dense numpy arrays of floating point values for the features. Read more in the :ref:`User Guide <sgd>`. **Parameters** loss : str, 'squared_loss', 'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive' The loss function to be used. Defaults to 'squared_loss' which refers to the ordinary least squares fit. 'huber' modifies 'squared_loss' to focus less on getting outliers correct by switching from squared to linear loss past a distance of epsilon. 'epsilon_insensitive' ignores errors less than epsilon and is linear past that; this is the loss function used in SVR. 'squared_epsilon_insensitive' is the same but becomes squared loss past a tolerance of epsilon. penalty : str, 'none', 'l2', 'l1', or 'elasticnet' The penalty (aka regularization term) to be used. Defaults to 'l2' which is the standard regularizer for linear SVM models. 'l1' and 'elasticnet' might bring sparsity to the model (feature selection) not achievable with 'l2'. alpha : float Constant that multiplies the regularization term. Defaults to 0.0001 Also used to compute learning_rate when set to 'optimal'. l1_ratio : float The Elastic Net mixing parameter, with 0 <= l1_ratio <= 1. l1_ratio=0 corresponds to L2 penalty, l1_ratio=1 to L1. Defaults to 0.15. fit_intercept : bool Whether the intercept should be estimated or not. If False, the data is assumed to be already centered. Defaults to True. n_iter : int, optional The number of passes over the training data (aka epochs). The number of iterations is set to 1 if using partial_fit. Defaults to 5. shuffle : bool, optional Whether or not the training data should be shuffled after each epoch. Defaults to True. random_state : int seed, RandomState instance, or None (default) The seed of the pseudo random number generator to use when shuffling the data. verbose : integer, optional The verbosity level. epsilon : float Epsilon in the epsiloninsensitive loss functions; only if `loss` is 'huber', 'epsilon_insensitive', or 'squared_epsilon_insensitive'. For 'huber', determines the threshold at which it becomes less important to get the prediction exactly right. For epsiloninsensitive, any differences between the current prediction and the correct label are ignored if they are less than this threshold. learning_rate : string, optional The learning rate:  constant: eta = eta0  optimal: eta = 1.0/(alpha * t)  invscaling: eta = eta0 / pow(t, power_t) [default] eta0 : double, optional The initial learning rate [default 0.01]. power_t : double, optional The exponent for inverse scaling learning rate [default 0.25]. warm_start : bool, optional When set to True, reuse the solution of the previous call to fit as initialization, otherwise, just erase the previous solution. average : bool or int, optional When set to True, computes the averaged SGD weights and stores the result in the ``coef_`` attribute. If set to an int greater than 1, averaging will begin once the total number of samples seen reaches average. So ``average=10 will`` begin averaging after seeing 10 samples. **Attributes** ``coef_`` : array, shape (n_features,) Weights assigned to the features. ``intercept_`` : array, shape (1,) The intercept term. ``average_coef_`` : array, shape (n_features,) Averaged weights assigned to the features. ``average_intercept_`` : array, shape (1,) The averaged intercept term. **Examples** >>> import numpy as np >>> from sklearn import linear_model >>> 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 = linear_model.SGDRegressor() >>> clf.fit(X, y) ... #doctest: +NORMALIZE_WHITESPACE SGDRegressor(alpha=0.0001, average=False, epsilon=0.1, eta0=0.01, fit_intercept=True, l1_ratio=0.15, learning_rate='invscaling', loss='squared_loss', n_iter=5, penalty='l2', power_t=0.25, random_state=None, shuffle=True, verbose=0, warm_start=False) See also Ridge, ElasticNet, Lasso, SVR




DEPRECATED: Support to use estimators as feature selectors will be removed in version 0.19. Use SelectFromModel instead. This node has been automatically generated by wrapping the ``sklearn.linear_model.stochastic_gradient.SGDRegressor`` class from the ``sklearn`` library. The wrapped instance can be accessed through the ``scikits_alg`` attribute. Reduce X to its most important features. Uses ``coef_`` or ``feature_importances_`` to determine the most important features. For models with a ``coef_`` for each class, the absolute sum over the classes is used. Parameters  X : array or scipy sparse matrix of shape [n_samples, n_features] The input samples. threshold : string, float or None, optional (default=None) The threshold value to use for feature selection. Features whose importance is greater or equal are kept while the others are discarded. If "median" (resp. "mean"), then the threshold value is the median (resp. the mean) of the feature importances. A scaling factor (e.g., "1.25*mean") may also be used. If None and if available, the object attribute ``threshold`` is used. Otherwise, "mean" is used by default. Returns  X_r : array of shape [n_samples, n_selected_features] The input samples with only the selected features.



Fit linear model with Stochastic Gradient Descent. This node has been automatically generated by wrapping the sklearn.linear_model.stochastic_gradient.SGDRegressor class from the sklearn library. The wrapped instance can be accessed through the scikits_alg attribute. Parameters
Returns self : returns an instance of self.

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