Python linear_model.Lasso方法代碼示例

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_with_complementary_pairs_bootstrap():
    n, p, k = 500, 1000, 5

    X, y, important_betas = _generate_dummy_regression_data(n=n, k=k)

    base_estimator = Pipeline([
        ('scaler', StandardScaler()),
        ('model', Lasso())
    ])

    lambdas_grid = np.logspace(-1, 1, num=10)

    selector = StabilitySelection(base_estimator=base_estimator,
                                  lambda_name='model__alpha',
                                  lambda_grid=lambdas_grid,
                                  bootstrap_func='complementary_pairs')
    selector.fit(X, y)

    chosen_betas = selector.get_support(indices=True)

    assert_almost_equal(important_betas, chosen_betas) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_stability_selection_regression():
    n, p, k = 500, 1000, 5

    X, y, important_betas = _generate_dummy_regression_data(n=n, k=k)

    base_estimator = Pipeline([
        ('scaler', StandardScaler()),
        ('model', Lasso())
    ])

    lambdas_grid = np.logspace(-1, 1, num=10)

    selector = StabilitySelection(base_estimator=base_estimator,
                                  lambda_name='model__alpha',
                                  lambda_grid=lambdas_grid)
    selector.fit(X, y)

    chosen_betas = selector.get_support(indices=True)

    assert_almost_equal(important_betas, chosen_betas) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_different_shape():
    n, p, k = 100, 200, 5

    X, y, important_betas = _generate_dummy_regression_data(n=n, k=k)

    base_estimator = Pipeline([
        ('scaler', StandardScaler()),
        ('model', Lasso())
    ])

    lambdas_grid = np.logspace(-1, 1, num=10)

    selector = StabilitySelection(base_estimator=base_estimator,
                                  lambda_name='model__alpha',
                                  lambda_grid=lambdas_grid)
    selector.fit(X, y)
    selector.transform(X[:, :-2]) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_no_features():
    n, p, k = 100, 200, 0

    X, y, important_betas = _generate_dummy_regression_data(n=n, k=k)

    base_estimator = Pipeline([
        ('scaler', StandardScaler()),
        ('model', Lasso())
    ])

    lambdas_grid = np.logspace(-1, 1, num=10)

    selector = StabilitySelection(base_estimator=base_estimator,
                                  lambda_name='model__alpha',
                                  lambda_grid=lambdas_grid)
    selector.fit(X, y)

    assert_almost_equal(selector.transform(X),
                        np.empty(0).reshape((X.shape[0], 0))) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_stability_plot():
    n, p, k = 500, 200, 5

    X, y, important_betas = _generate_dummy_regression_data(n=n, k=k)

    base_estimator = Pipeline([
        ('scaler', StandardScaler()),
        ('model', Lasso())
    ])

    lambdas_grid = np.logspace(-1, 1, num=10)

    selector = StabilitySelection(base_estimator=base_estimator,
                                  lambda_name='model__alpha',
                                  lambda_grid=lambdas_grid)
    selector.fit(X, y)

    plot_stability_path(selector, threshold_highlight=0.5) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def build_ensemble(**kwargs):
    """Generate ensemble."""

    ens = SuperLearner(**kwargs)
    prep = {'Standard Scaling': [StandardScaler()],
            'Min Max Scaling': [MinMaxScaler()],
            'No Preprocessing': []}

    est = {'Standard Scaling':
               [ElasticNet(), Lasso(), KNeighborsRegressor()],
           'Min Max Scaling':
               [SVR()],
           'No Preprocessing':
               [RandomForestRegressor(random_state=SEED),
                GradientBoostingRegressor()]}

    ens.add(est, prep)

    ens.add(GradientBoostingRegressor(), meta=True)

    return ens 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_transform_target_regressor_error():
    X, y = friedman
    # provide a transformer and functions at the same time
    regr = TransformedTargetRegressor(regressor=LinearRegression(),
                                      transformer=StandardScaler(),
                                      func=np.exp, inverse_func=np.log)
    assert_raises_regex(ValueError, "'transformer' and functions"
                        " 'func'/'inverse_func' cannot both be set.",
                        regr.fit, X, y)
    # fit with sample_weight with a regressor which does not support it
    sample_weight = np.ones((y.shape[0],))
    regr = TransformedTargetRegressor(regressor=Lasso(),
                                      transformer=StandardScaler())
    assert_raises_regex(TypeError, r"fit\(\) got an unexpected keyword "
                        "argument 'sample_weight'", regr.fit, X, y,
                        sample_weight=sample_weight)
    # func is given but inverse_func is not
    regr = TransformedTargetRegressor(func=np.exp)
    assert_raises_regex(ValueError, "When 'func' is provided, 'inverse_func'"
                        " must also be provided", regr.fit, X, y) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_multi_target_regression_partial_fit():
    X, y = datasets.make_regression(n_targets=3)
    X_train, y_train = X[:50], y[:50]
    X_test, y_test = X[50:], y[50:]

    references = np.zeros_like(y_test)
    half_index = 25
    for n in range(3):
        sgr = SGDRegressor(random_state=0, max_iter=5)
        sgr.partial_fit(X_train[:half_index], y_train[:half_index, n])
        sgr.partial_fit(X_train[half_index:], y_train[half_index:, n])
        references[:, n] = sgr.predict(X_test)

    sgr = MultiOutputRegressor(SGDRegressor(random_state=0, max_iter=5))

    sgr.partial_fit(X_train[:half_index], y_train[:half_index])
    sgr.partial_fit(X_train[half_index:], y_train[half_index:])

    y_pred = sgr.predict(X_test)
    assert_almost_equal(references, y_pred)
    assert not hasattr(MultiOutputRegressor(Lasso), 'partial_fit') 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_rank_deficient_design():
    # consistency test that checks that LARS Lasso is handling rank
    # deficient input data (with n_features < rank) in the same way
    # as coordinate descent Lasso
    y = [5, 0, 5]
    for X in (
              [[5, 0],
               [0, 5],
               [10, 10]],
              [[10, 10, 0],
               [1e-32, 0, 0],
               [0, 0, 1]]
             ):
        # To be able to use the coefs to compute the objective function,
        # we need to turn off normalization
        lars = linear_model.LassoLars(.1, normalize=False)
        coef_lars_ = lars.fit(X, y).coef_
        obj_lars = (1. / (2. * 3.)
                    * linalg.norm(y - np.dot(X, coef_lars_)) ** 2
                    + .1 * linalg.norm(coef_lars_, 1))
        coord_descent = linear_model.Lasso(.1, tol=1e-6, normalize=False)
        coef_cd_ = coord_descent.fit(X, y).coef_
        obj_cd = ((1. / (2. * 3.)) * linalg.norm(y - np.dot(X, coef_cd_)) ** 2
                  + .1 * linalg.norm(coef_cd_, 1))
        assert_less(obj_lars, obj_cd * (1. + 1e-8)) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def test_lasso_lars_vs_lasso_cd_early_stopping():
    # Test that LassoLars and Lasso using coordinate descent give the
    # same results when early stopping is used.
    # (test : before, in the middle, and in the last part of the path)
    alphas_min = [10, 0.9, 1e-4]

    for alpha_min in alphas_min:
        alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
                                                       alpha_min=alpha_min)
        lasso_cd = linear_model.Lasso(fit_intercept=False, tol=1e-8)
        lasso_cd.alpha = alphas[-1]
        lasso_cd.fit(X, y)
        error = linalg.norm(lasso_path[:, -1] - lasso_cd.coef_)
        assert_less(error, 0.01)

    # same test, with normalization
    for alpha_min in alphas_min:
        alphas, _, lasso_path = linear_model.lars_path(X, y, method='lasso',
                                                       alpha_min=alpha_min)
        lasso_cd = linear_model.Lasso(fit_intercept=True, normalize=True,
                                      tol=1e-8)
        lasso_cd.alpha = alphas[-1]
        lasso_cd.fit(X, y)
        error = linalg.norm(lasso_path[:, -1] - lasso_cd.coef_)
        assert_less(error, 0.01) 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def lasso(df, dependent_variable, independent_variables, interaction_terms=[], model_limit=5):
    considered_independent_variables_per_model, patsy_models = \
    construct_models(df, dependent_variable, independent_variables, interaction_terms, table_layout=MCT.ALL_VARIABLES.value)
    y, X = dmatrices(patsy_models[0], df, return_type='dataframe')

    clf = linear_model.Lasso(
        alpha = 1.0,
        normalize=True
    )
    clf.fit(X, y)
    fit_coef = clf.coef_
    column_means = np.apply_along_axis(np.mean, 1, X)

    selected_variables = [ independent_variable for (i, independent_variable) in enumerate(independent_variables) if ( abs(fit_coef[i]) >= column_means[i] ) ]

    return selected_variables 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def getModels():
    result = []
    result.append("LinearRegression")
    result.append("BayesianRidge")
    result.append("ARDRegression")
    result.append("ElasticNet")
    result.append("HuberRegressor")
    result.append("Lasso")
    result.append("LassoLars")
    result.append("Rigid")
    result.append("SGDRegressor")
    result.append("SVR")
    result.append("MLPClassifier")
    result.append("KNeighborsClassifier")
    result.append("SVC")
    result.append("GaussianProcessClassifier")
    result.append("DecisionTreeClassifier")
    result.append("RandomForestClassifier")
    result.append("AdaBoostClassifier")
    result.append("GaussianNB")
    result.append("LogisticRegression")
    result.append("QuadraticDiscriminantAnalysis")
    return result 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def comp_attack_vld(self,clf,wxc,bxc,wyc,byc,otherargs):
        n = self.vldx.shape[0]
        res = (clf.predict(self.vldx)-self.vldy)

        gradx = np.dot(self.vldx, wxc)   + bxc
        grady = np.dot(self.vldx, wyc.T) + byc

        attackx = np.dot(res,gradx) / n
        attacky = np.dot(res,grady) / n

        return attackx, attacky


############################################################################################
# Implements GD Poisoning for Lasso Linear Regression
############################################################################################ 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def learn_model(self, x, y, clf, lam = None):
        if (lam is None and self.initlam != -1): # hack for first training
            lam = self.initlam
        if clf is None:
            if lam is None:
                clf = linear_model.LassoCV(max_iter=10000)
                clf.fit(x, y)
                lam = clf.alpha_
            clf = linear_model.Lasso(alpha = lam, \
                                 max_iter = 10000, \
                                 warm_start = True)
        clf.fit(x, y)
        return clf, lam


############################################################################################
# Implements GD Poisoning for Ridge Linear Regression
############################################################################################ 

# 需要導入模塊: from sklearn import linear_model [as 別名]
# 或者: from sklearn.linear_model import Lasso [as 別名]
def lasso_correlation_matrix(vec1, vec2, random_state=None):
  """Computes correlation matrix of two representations using Lasso Regression.

  Args:
    vec1: 2d array of representations with axis 0 the batch dimension and axis 1
      the representation dimension.
    vec2: 2d array of representations with axis 0 the batch dimension and axis 1
      the representation dimension.
    random_state: int used to seed an RNG used for model training.

  Returns:
    A 2d array with the correlations between all pairwise combinations of
    elements of both representations are computed. Elements of vec1 correspond
    to axis 0 and elements of vec2 correspond to axis 1.
  """
  assert vec1.shape == vec2.shape
  model = linear_model.Lasso(random_state=random_state, alpha=0.1)
  model.fit(vec1, vec2)
  return np.transpose(np.absolute(model.coef_))