EX: Show example of pickling and parallel use.

demo/guide-python/sklearn_examples.py

@@ -4,60 +4,86 @@
 
 @author: Jamie Hall
 '''
+if __name__ == "__main__":
+    # NOTE: This *has* to be here and in the `__name__ == "__main__"` clause
+    # to run XGBoost in parallel, if XGBoost was built with OpenMP support.
+    # Otherwise, you can use fork, which is the default backend for joblib,
+    # and omit this.
+    from multiprocessing import set_start_method
+    set_start_method("forkserver")
 
-import xgboost as xgb
-
-import numpy as np
-from sklearn.cross_validation import KFold
-from sklearn.grid_search import GridSearchCV
-from sklearn.metrics import confusion_matrix, mean_squared_error
-from sklearn.datasets import load_iris, load_digits, load_boston
-
-rng = np.random.RandomState(31337)
-
-
-print("Zeros and Ones from the Digits dataset: binary classification")
-digits = load_digits(2)
-y = digits['target']
-X = digits['data']
-kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
-for train_index, test_index in kf:
-    xgb_model = xgb.XGBClassifier().fit(X[train_index],y[train_index])
-    predictions = xgb_model.predict(X[test_index])
-    actuals = y[test_index]
-    print(confusion_matrix(actuals, predictions))
-
-print("Iris: multiclass classification")
-iris = load_iris()
-y = iris['target']
-X = iris['data']
-kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
-for train_index, test_index in kf:
-    xgb_model = xgb.XGBClassifier().fit(X[train_index],y[train_index])
-    predictions = xgb_model.predict(X[test_index])
-    actuals = y[test_index]
-    print(confusion_matrix(actuals, predictions))
-
-print("Boston Housing: regression")
-boston = load_boston()
-y = boston['target']
-X = boston['data']
-kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
-for train_index, test_index in kf:
-    xgb_model = xgb.XGBRegressor().fit(X[train_index],y[train_index])
-    predictions = xgb_model.predict(X[test_index])
-    actuals = y[test_index]
-    print(mean_squared_error(actuals, predictions))
-
-print("Parameter optimization")
-y = boston['target']
-X = boston['data']
-xgb_model = xgb.XGBRegressor()
-clf = GridSearchCV(xgb_model,
-                   {'max_depth': [2,4,6],
-                    'n_estimators': [50,100,200]}, verbose=1)
-clf.fit(X,y)
-print(clf.best_score_)
-print(clf.best_params_)
+    import pickle
+    import os
+    import xgboost as xgb
 
+    import numpy as np
+    from sklearn.cross_validation import KFold
+    from sklearn.grid_search import GridSearchCV
+    from sklearn.metrics import confusion_matrix, mean_squared_error
+    from sklearn.datasets import load_iris, load_digits, load_boston
 
+    rng = np.random.RandomState(31337)
+
+    print("Zeros and Ones from the Digits dataset: binary classification")
+    digits = load_digits(2)
+    y = digits['target']
+    X = digits['data']
+    kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
+    for train_index, test_index in kf:
+        xgb_model = xgb.XGBClassifier().fit(X[train_index],y[train_index])
+        predictions = xgb_model.predict(X[test_index])
+        actuals = y[test_index]
+        print(confusion_matrix(actuals, predictions))
+
+    print("Iris: multiclass classification")
+    iris = load_iris()
+    y = iris['target']
+    X = iris['data']
+    kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
+    for train_index, test_index in kf:
+        xgb_model = xgb.XGBClassifier().fit(X[train_index],y[train_index])
+        predictions = xgb_model.predict(X[test_index])
+        actuals = y[test_index]
+        print(confusion_matrix(actuals, predictions))
+
+    print("Boston Housing: regression")
+    boston = load_boston()
+    y = boston['target']
+    X = boston['data']
+    kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
+    for train_index, test_index in kf:
+        xgb_model = xgb.XGBRegressor().fit(X[train_index],y[train_index])
+        predictions = xgb_model.predict(X[test_index])
+        actuals = y[test_index]
+        print(mean_squared_error(actuals, predictions))
+
+    print("Parameter optimization")
+    y = boston['target']
+    X = boston['data']
+    xgb_model = xgb.XGBRegressor()
+    clf = GridSearchCV(xgb_model,
+                       {'max_depth': [2,4,6],
+                        'n_estimators': [50,100,200]}, verbose=1)
+    clf.fit(X,y)
+    print(clf.best_score_)
+    print(clf.best_params_)
+
+    # The sklearn API models are picklable
+    print("Pickling sklearn API models")
+    # must open in binary format to pickle
+    pickle.dump(clf, open("best_boston.pkl", "wb"))
+    clf2 = pickle.load(open("best_boston.pkl", "rb"))
+    print(np.allclose(clf.predict(X), clf2.predict(X)))
+
+    print("Parallel Parameter optimization")
+    os.environ["OMP_NUM_THREADS"] = "1"
+    y = boston['target']
+    X = boston['data']
+    xgb_model = xgb.XGBRegressor()
+    clf = GridSearchCV(xgb_model,
+                       {'max_depth': [2,4,6],
+                        'n_estimators': [50,100,200]}, verbose=1,
+                       n_jobs=2)
+    clf.fit(X, y)
+    print(clf.best_score_)
+    print(clf.best_params_)