Python model_selection.RandomizedSearchCV方法代碼示例

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def getTunedModel( self, baseModel ):
        n_estimators = [100, 200, 300, 400, 500]
        max_features = ['auto', 'sqrt']
        max_depth = [5, 10, 20, 30, 40, 50]
        min_samples_split = [2, 5, 10]
        min_samples_leaf = [1, 2, 4]
        bootstrap = [True, False]
        
        random_grid = {'n_estimators': n_estimators,
                       'max_features': max_features,
                       'max_depth': max_depth,
                       'min_samples_split': min_samples_split,
                       'min_samples_leaf': min_samples_leaf,
                       'bootstrap': bootstrap}
        #print(random_grid)
        
        model_tuned = RandomizedSearchCV(estimator = baseModel, param_distributions = random_grid, n_iter = 2, cv = 2, verbose=0, random_state=100 , n_jobs = -1)
        return model_tuned
        
  

        
        

###################################################################################################################################### 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def fit(self, X, y=None, groups=None):
            """Run fit on the estimator with randomly drawn parameters.

            Parameters
            ----------

            X : array-like, shape=(n_samples, n_features)
                Training vector, where n_samples is the number of samples and
                n_features is the number of features.

            y : array-like, shape=(n_samples,) or (n_samples, n_output), optional (default=None)
                Target relative to X for classification or regression;
                None for unsupervised learning.

            groups : array-like, shape=(n_samples,), optional (default=None)
                Group labels for the samples used while splitting the dataset into
                train/test set.
            """
            return super(RandomizedSearchCV, self).fit(X, _as_numpy(y), groups) 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def _prepare_classifier(self, params, n_jobs=1):

        X_train, y_train = params

        tuned_parameters = [{
            'kernel': ['rbf'], 
            'gamma': [1e-4,1e-3,1e-2,1e-1,1e+0,1e+1,1e+2,1e+3,1e+4],
            'C': [1e+0,1e+1,1e+2,1e+3,1e+4,1e+5,1e+6,1e+7,1e+8,1e+9]
        }]

        clf=RandomizedSearchCV(svm.SVC(random_state=self.random_state), 
                               tuned_parameters[0], 
                               n_iter=self.n_randomized_search_iter, 
                               n_jobs=n_jobs, random_state=self.random_state)
        clf.fit(X_train, y_train)
              
        params=clf.best_params_
        clf=svm.SVC(kernel=params['kernel'], C=params['C'], 
            gamma=params['gamma'], probability=True, 
            random_state=self.random_state)
        clf.fit(X_train, y_train)

        return clf 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_empty_cv_iterator_error():
    # Use global X, y

    # create cv
    cv = KFold(n_splits=3).split(X)

    # pop all of it, this should cause the expected ValueError
    [u for u in cv]
    # cv is empty now

    train_size = 100
    ridge = RandomizedSearchCV(Ridge(), {'alpha': [1e-3, 1e-2, 1e-1]},
                               cv=cv, n_jobs=-1)

    # assert that this raises an error
    with pytest.raises(ValueError,
                       match='No fits were performed. '
                             'Was the CV iterator empty\\? '
                             'Were there no candidates\\?'):
        ridge.fit(X[:train_size], y[:train_size]) 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_random_search_bad_cv():
    # Use global X, y

    class BrokenKFold(KFold):
        def get_n_splits(self, *args, **kw):
            return 1

    # create bad cv
    cv = BrokenKFold(n_splits=3)

    train_size = 100
    ridge = RandomizedSearchCV(Ridge(), {'alpha': [1e-3, 1e-2, 1e-1]},
                               cv=cv, n_jobs=-1)

    # assert that this raises an error
    with pytest.raises(ValueError,
                       match='cv.split and cv.get_n_splits returned '
                             'inconsistent results. Expected \\d+ '
                             'splits, got \\d+'):
        ridge.fit(X[:train_size], y[:train_size]) 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def randomized_search(self, **kwargs):
        """Randomized search using sklearn.model_selection.RandomizedSearchCV.

        Any parameters typically associated with RandomizedSearchCV (see
        sklearn documentation) can be passed as keyword arguments to this
        function.

        The final dictionary used for the randomized search is saved to
        `self.randomized_search_params`. This is updated with any parameters
        that are passed.

        Examples
        --------
        # Passing kwargs.
        self.randomized_search(param_distributions={'max_depth':[2,3,5,10]}, refit=True)

        """
        self.randomized_search_params.update(kwargs)
        self.rand_search_ = RandomizedSearchCV(**self.randomized_search_params)
        self.rand_search_.fit(self.x_train, self.transformed_y_train)
        return self.rand_search_ 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def fit(self, X, y):
        """Deploys `fit` jobs to each worker in the cluster.
        """
        timestamp = str(int(time.time()))
        self.task_name = self.task_name or '{}.{}.{}'.format(self.cluster_id, self.image_name, timestamp)
        self._done = False
        self._cancelled = False

        X_uri, y_uri, _ = self._upload_data(X, y)

        if type(self.search) == GridSearchCV:
            handler = self._handle_grid_search
        elif type(self.search) == RandomizedSearchCV:
            handler = self._handle_randomized_search
        elif type(self.search) == BayesSearchCV:
            handler = self._handle_bayes_search

        print('Fitting {}'.format(type(self.search)))
        handler(X_uri, y_uri)

        self.persist() 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def random_forest(verbose: int = 0, n_jobs: int = 1):
  """Setup a random forest pipeline with cross-validation."""
  rf = ensemble.RandomForestClassifier()

  n_estimators = [100]
  max_features = ['auto', 'sqrt']
  max_depth = [5, 10, 20]
  max_depth.append(None)
  min_samples_split = [2, 5, 10]
  min_samples_leaf = [1, 2, 4]
  random_grid = {'n_estimators': n_estimators,
                 'max_features': max_features,
                 'max_depth': max_depth,
                 'min_samples_split': min_samples_split,
                 'min_samples_leaf': min_samples_leaf}

  pipe = model_selection.RandomizedSearchCV(
      rf, param_distributions=random_grid, n_iter=7, cv=3, n_jobs=n_jobs,
      iid=False, verbose=verbose)
  return pipe 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_with_randomizedsearchcv(self):
        from sklearn.model_selection import RandomizedSearchCV
        from sklearn.datasets import load_iris
        from sklearn.metrics import accuracy_score, make_scorer
        from scipy.stats.distributions import uniform
        import numpy as np
        lr = LogisticRegression()
        parameters = {'solver':('liblinear', 'lbfgs'), 'penalty':['l2']}
        ranges, cat_idx = lr.get_param_ranges()
        min_C, max_C, default_C = ranges['C']
        # specify parameters and distributions to sample from
        #the loguniform distribution needs to be taken care of properly
        param_dist = {"solver": ranges['solver'],
                      "C": uniform(min_C, np.log(max_C))}
        # run randomized search
        n_iter_search = 5
        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            random_search = RandomizedSearchCV(
                lr, param_distributions=param_dist, n_iter=n_iter_search, cv=5,
                scoring=make_scorer(accuracy_score))
            iris = load_iris()
            random_search.fit(iris.data, iris.target) 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def _select_classifier_from_sk_search(estimator, X, A):
    """Return best model from a scikit-learn Search-estimator model.

    Args:
        estimator (GridSearchCV | RandomizedSearchCV): An initialized sklearn SearchCV classifier.
        X (np.ndarray): Covariate matrix size (num_samples, num_features)
        A (np.ndarray): binary labels indicating the source and target populations (num_samples,)

    Returns:
        classifier: model.best_estimator_ - best-performing classifier.
                    See scikit-learn's GridSearchCV and RandomizedSearchCV documentation for details on their return
                    values.
    """
    estimator.fit(X, A)
    best_estimator = clone(estimator.best_estimator_)
    return best_estimator 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def learn(self):
        X, y = self.__get_data()
        feature_names =list(X.columns.values)
        if self._undersampling:
            X, y = self.__undersample(feature_names, X, y)

        if self._feature_selection:
            X = self.__select_features(X, y, feature_names)

        if self._scaling:
            logging.info("Scaling...")
            X = preprocessing.scale(X)

        rgs = RandomizedSearchCV(estimator=self._classifier[1], param_distributions=self._classifier[2],
                                 error_score=0, cv=QuincyConfig.CV, n_iter=QuincyConfig.ITERS, refit=True,
                                 n_jobs=-1, scoring=QuincyConfig.METRIC, iid=False)
        rgs.fit(X, y)
        logging.info("Best SCORE: %s" % str(rgs.best_score_))
        logging.info("Best Params: %s" % str(rgs.best_params_))
        self._optimized_model = rgs 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_search_cv_timing():
    svc = LinearSVC(random_state=0)

    X = [[1, ], [2, ], [3, ], [4, ]]
    y = [0, 1, 1, 0]

    gs = GridSearchCV(svc, {'C': [0, 1]}, cv=2, error_score=0)
    rs = RandomizedSearchCV(svc, {'C': [0, 1]}, cv=2, error_score=0, n_iter=2)

    for search in (gs, rs):
        search.fit(X, y)
        for key in ['mean_fit_time', 'std_fit_time']:
            # NOTE The precision of time.time in windows is not high
            # enough for the fit/score times to be non-zero for trivial X and y
            assert_true(np.all(search.cv_results_[key] >= 0))
            assert_true(np.all(search.cv_results_[key] < 1))

        for key in ['mean_score_time', 'std_score_time']:
            assert_true(search.cv_results_[key][1] >= 0)
            assert_true(search.cv_results_[key][0] == 0.0)
            assert_true(np.all(search.cv_results_[key] < 1)) 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def get_algorithm(estimator,
                  scoring_metric,
                  hyperparameter_grid,
                  randomized_search,
                  number_iteration_samples=10,
                  **non_randomized_estimator_kwargs):
    """
    Given an estimator and various params, initialize an algorithm with optional randomized search.

    Args:
        estimator (sklearn.base.BaseEstimator): a scikit-learn estimator (for example: KNeighborsClassifier)
        scoring_metric (str): The scoring metric to optimized for if using random search. See
            http://scikit-learn.org/stable/modules/model_evaluation.html
        hyperparameter_grid (dict): An object containing key value pairs of the specific hyperparameter space to search
            through.
        randomized_search (bool): Whether the method should return a randomized search estimator (as opposed to a
            simple algorithm).
        number_iteration_samples (int): If performing randomized search, this is the number of samples that are run in 
            the hyperparameter space. Higher numbers will be slower, but end up with better results, since it is more
            likely that the true optimal hyperparameter is found.
        **non_randomized_estimator_kwargs: Keyword arguments that you can pass directly to the algorithm. Only used when
            radomized_search is False

    Returns:
        sklearn.base.BaseEstimator: a scikit learn algorithm ready to `.fit()`

    """
    if randomized_search:
        algorithm = RandomizedSearchCV(estimator=estimator(),
                                       scoring=scoring_metric,
                                       param_distributions=hyperparameter_grid,
                                       n_iter=number_iteration_samples,
                                       verbose=0,
                                       n_jobs=1)

    else:
        algorithm = estimator(**non_randomized_estimator_kwargs)

    return algorithm 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_randomgridsearch_slm(make_gaus_data):

    X, y, Xs, ys = make_gaus_data

    slm = StandardLinearModel(LinearBasis(onescol=True))

    param_dict = {
        'var': [Parameter(1.0 / v, Positive()) for v in range(1, 6)]
    }
    estimator = RandomizedSearchCV(slm, param_dict, n_jobs=-1, n_iter=2)

    estimator.fit(X, y)
    Ey = estimator.predict(Xs)
    assert len(ys) == len(Ey)  # we just want to make sure this all runs 

# 需要導入模塊: from sklearn import model_selection [as 別名]
# 或者: from sklearn.model_selection import RandomizedSearchCV [as 別名]
def test_randomgridsearch_glm(make_gaus_data):

    X, y, Xs, ys = make_gaus_data

    glm = GeneralizedLinearModel(Gaussian(), LinearBasis(onescol=True),
                                 random_state=1, maxiter=100)

    param_dict = {'batch_size': range(1, 11)}
    estimator = RandomizedSearchCV(glm, param_dict, verbose=1, n_jobs=-1,
                                   n_iter=2)

    estimator.fit(X, y)
    Ey = estimator.predict(Xs)
    assert len(ys) == len(Ey)  # we just want to make sure this all runs