xgboost/tests/python/test_with_sklearn.py
Philip Hyunsu Cho 86d88c0758
Fix #3648: XGBClassifier.predict() should return margin scores when output_margin=True (#3651)
* Fix #3648: XGBClassifier.predict() should return margin scores when output_margin=True

* Fix tests to reflect correct implementation of XGBClassifier.predict(output_margin=True)

* Fix flaky test test_with_sklearn.test_sklearn_api_gblinear
2018-08-30 21:05:05 -07:00

543 lines
18 KiB
Python

import numpy as np
import xgboost as xgb
import testing as tm
import tempfile
import os
import shutil
from nose.tools import raises
rng = np.random.RandomState(1994)
class TemporaryDirectory(object):
"""Context manager for tempfile.mkdtemp()"""
def __enter__(self):
self.name = tempfile.mkdtemp()
return self.name
def __exit__(self, exc_type, exc_value, traceback):
shutil.rmtree(self.name)
def test_binary_classification():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
try:
from sklearn.model_selection import KFold
except:
from sklearn.cross_validation import KFold
digits = load_digits(2)
y = digits['target']
X = digits['data']
try:
kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
except TypeError: # sklearn.model_selection.KFold uses n_split
kf = KFold(
n_splits=2, shuffle=True, random_state=rng
).split(np.arange(y.shape[0]))
for train_index, test_index in kf:
xgb_model = xgb.XGBClassifier().fit(X[train_index], y[train_index])
preds = xgb_model.predict(X[test_index])
labels = y[test_index]
err = sum(1 for i in range(len(preds))
if int(preds[i] > 0.5) != labels[i]) / float(len(preds))
assert err < 0.1
def test_multiclass_classification():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_iris
try:
from sklearn.cross_validation import KFold
except:
from sklearn.model_selection import KFold
def check_pred(preds, labels, output_margin):
if output_margin:
err = sum(1 for i in range(len(preds))
if preds[i].argmax() != labels[i]) / float(len(preds))
else:
err = sum(1 for i in range(len(preds))
if preds[i] != labels[i]) / float(len(preds))
assert err < 0.4
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])
preds = xgb_model.predict(X[test_index])
# test other params in XGBClassifier().fit
preds2 = xgb_model.predict(X[test_index], output_margin=True, ntree_limit=3)
preds3 = xgb_model.predict(X[test_index], output_margin=True, ntree_limit=0)
preds4 = xgb_model.predict(X[test_index], output_margin=False, ntree_limit=3)
labels = y[test_index]
check_pred(preds, labels, output_margin=False)
check_pred(preds2, labels, output_margin=True)
check_pred(preds3, labels, output_margin=True)
check_pred(preds4, labels, output_margin=False)
def test_ranking():
tm._skip_if_no_sklearn()
# generate random data
x_train = np.random.rand(1000, 10)
y_train = np.random.randint(5, size=1000)
train_group = np.repeat(50, 20)
x_valid = np.random.rand(200, 10)
y_valid = np.random.randint(5, size=200)
valid_group = np.repeat(50, 4)
x_test = np.random.rand(100, 10)
params = {'objective': 'rank:pairwise', 'learning_rate': 0.1,
'gamma': 1.0, 'min_child_weight': 0.1,
'max_depth': 6, 'n_estimators': 4}
model = xgb.sklearn.XGBRanker(**params)
model.fit(x_train, y_train, train_group,
eval_set=[(x_valid, y_valid)], eval_group=[valid_group])
pred = model.predict(x_test)
train_data = xgb.DMatrix(x_train, y_train)
valid_data = xgb.DMatrix(x_valid, y_valid)
test_data = xgb.DMatrix(x_test)
train_data.set_group(train_group)
valid_data.set_group(valid_group)
params_orig = {'objective': 'rank:pairwise', 'eta': 0.1, 'gamma': 1.0,
'min_child_weight': 0.1, 'max_depth': 6}
xgb_model_orig = xgb.train(params_orig, train_data, num_boost_round=4,
evals=[(valid_data, 'validation')])
pred_orig = xgb_model_orig.predict(test_data)
np.testing.assert_almost_equal(pred, pred_orig)
def test_feature_importances():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
digits = load_digits(2)
y = digits['target']
X = digits['data']
xgb_model = xgb.XGBClassifier(seed=0).fit(X, y)
exp = np.array([0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.00833333, 0.,
0., 0., 0., 0., 0., 0., 0., 0.025, 0.14166667, 0., 0., 0.,
0., 0., 0., 0.00833333, 0.25833333, 0., 0., 0., 0.,
0.03333334, 0.03333334, 0., 0.32499999, 0., 0., 0., 0.,
0.05, 0.06666667, 0., 0., 0., 0., 0., 0., 0., 0.04166667,
0., 0., 0., 0., 0., 0., 0., 0.00833333, 0., 0., 0., 0.,
0.], dtype=np.float32)
np.testing.assert_almost_equal(xgb_model.feature_importances_, exp)
# numeric columns
import pandas as pd
y = pd.Series(digits['target'])
X = pd.DataFrame(digits['data'])
xgb_model = xgb.XGBClassifier(seed=0).fit(X, y)
np.testing.assert_almost_equal(xgb_model.feature_importances_, exp)
xgb_model = xgb.XGBClassifier(seed=0).fit(X, y)
np.testing.assert_almost_equal(xgb_model.feature_importances_, exp)
def test_boston_housing_regression():
tm._skip_if_no_sklearn()
from sklearn.metrics import mean_squared_error
from sklearn.datasets import load_boston
from sklearn.cross_validation import KFold
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])
preds = xgb_model.predict(X[test_index])
# test other params in XGBRegressor().fit
preds2 = xgb_model.predict(X[test_index], output_margin=True, ntree_limit=3)
preds3 = xgb_model.predict(X[test_index], output_margin=True, ntree_limit=0)
preds4 = xgb_model.predict(X[test_index], output_margin=False, ntree_limit=3)
labels = y[test_index]
assert mean_squared_error(preds, labels) < 25
assert mean_squared_error(preds2, labels) < 350
assert mean_squared_error(preds3, labels) < 25
assert mean_squared_error(preds4, labels) < 350
def test_parameter_tuning():
tm._skip_if_no_sklearn()
from sklearn.grid_search import GridSearchCV
from sklearn.datasets import load_boston
boston = load_boston()
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)
assert clf.best_score_ < 0.7
assert clf.best_params_ == {'n_estimators': 100, 'max_depth': 4}
def test_regression_with_custom_objective():
tm._skip_if_no_sklearn()
from sklearn.metrics import mean_squared_error
from sklearn.datasets import load_boston
from sklearn.cross_validation import KFold
def objective_ls(y_true, y_pred):
grad = (y_pred - y_true)
hess = np.ones(len(y_true))
return grad, hess
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(objective=objective_ls).fit(
X[train_index], y[train_index]
)
preds = xgb_model.predict(X[test_index])
labels = y[test_index]
assert mean_squared_error(preds, labels) < 25
# Test that the custom objective function is actually used
class XGBCustomObjectiveException(Exception):
pass
def dummy_objective(y_true, y_pred):
raise XGBCustomObjectiveException()
xgb_model = xgb.XGBRegressor(objective=dummy_objective)
np.testing.assert_raises(XGBCustomObjectiveException, xgb_model.fit, X, y)
def test_classification_with_custom_objective():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
from sklearn.cross_validation import KFold
def logregobj(y_true, y_pred):
y_pred = 1.0 / (1.0 + np.exp(-y_pred))
grad = y_pred - y_true
hess = y_pred * (1.0 - y_pred)
return grad, hess
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(objective=logregobj)
xgb_model.fit(X[train_index], y[train_index])
preds = xgb_model.predict(X[test_index])
labels = y[test_index]
err = sum(1 for i in range(len(preds))
if int(preds[i] > 0.5) != labels[i]) / float(len(preds))
assert err < 0.1
# Test that the custom objective function is actually used
class XGBCustomObjectiveException(Exception):
pass
def dummy_objective(y_true, y_preds):
raise XGBCustomObjectiveException()
xgb_model = xgb.XGBClassifier(objective=dummy_objective)
np.testing.assert_raises(
XGBCustomObjectiveException,
xgb_model.fit,
X, y
)
def test_sklearn_api():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_iris
from sklearn.cross_validation import train_test_split
iris = load_iris()
tr_d, te_d, tr_l, te_l = train_test_split(iris.data, iris.target, train_size=120)
classifier = xgb.XGBClassifier(booster='gbtree', n_estimators=10)
classifier.fit(tr_d, tr_l)
preds = classifier.predict(te_d)
labels = te_l
err = sum([1 for p, l in zip(preds, labels) if p != l]) * 1.0 / len(te_l)
assert err < 0.2
def test_sklearn_api_gblinear():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_iris
from sklearn.cross_validation import train_test_split
iris = load_iris()
tr_d, te_d, tr_l, te_l = train_test_split(iris.data, iris.target, train_size=120)
classifier = xgb.XGBClassifier(booster='gblinear', n_estimators=100)
classifier.fit(tr_d, tr_l)
preds = classifier.predict(te_d)
labels = te_l
err = sum([1 for p, l in zip(preds, labels) if p != l]) * 1.0 / len(te_l)
assert err < 0.5
def test_sklearn_plotting():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_iris
iris = load_iris()
classifier = xgb.XGBClassifier()
classifier.fit(iris.data, iris.target)
import matplotlib
matplotlib.use('Agg')
from matplotlib.axes import Axes
from graphviz import Digraph
ax = xgb.plot_importance(classifier)
assert isinstance(ax, Axes)
assert ax.get_title() == 'Feature importance'
assert ax.get_xlabel() == 'F score'
assert ax.get_ylabel() == 'Features'
assert len(ax.patches) == 4
g = xgb.to_graphviz(classifier, num_trees=0)
assert isinstance(g, Digraph)
ax = xgb.plot_tree(classifier, num_trees=0)
assert isinstance(ax, Axes)
def test_sklearn_nfolds_cv():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
from sklearn.model_selection import StratifiedKFold
digits = load_digits(3)
X = digits['data']
y = digits['target']
dm = xgb.DMatrix(X, label=y)
params = {
'max_depth': 2,
'eta': 1,
'silent': 1,
'objective':
'multi:softprob',
'num_class': 3
}
seed = 2016
nfolds = 5
skf = StratifiedKFold(n_splits=nfolds, shuffle=True, random_state=seed)
cv1 = xgb.cv(params, dm, num_boost_round=10, nfold=nfolds, seed=seed)
cv2 = xgb.cv(params, dm, num_boost_round=10, nfold=nfolds, folds=skf, seed=seed)
cv3 = xgb.cv(params, dm, num_boost_round=10, nfold=nfolds, stratified=True, seed=seed)
assert cv1.shape[0] == cv2.shape[0] and cv2.shape[0] == cv3.shape[0]
assert cv2.iloc[-1, 0] == cv3.iloc[-1, 0]
def test_split_value_histograms():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
digits_2class = load_digits(2)
X = digits_2class['data']
y = digits_2class['target']
dm = xgb.DMatrix(X, label=y)
params = {'max_depth': 6, 'eta': 0.01, 'silent': 1, 'objective': 'binary:logistic'}
gbdt = xgb.train(params, dm, num_boost_round=10)
assert gbdt.get_split_value_histogram("not_there", as_pandas=True).shape[0] == 0
assert gbdt.get_split_value_histogram("not_there", as_pandas=False).shape[0] == 0
assert gbdt.get_split_value_histogram("f28", bins=0).shape[0] == 1
assert gbdt.get_split_value_histogram("f28", bins=1).shape[0] == 1
assert gbdt.get_split_value_histogram("f28", bins=2).shape[0] == 2
assert gbdt.get_split_value_histogram("f28", bins=5).shape[0] == 2
assert gbdt.get_split_value_histogram("f28", bins=None).shape[0] == 2
def test_sklearn_random_state():
tm._skip_if_no_sklearn()
clf = xgb.XGBClassifier(random_state=402)
assert clf.get_xgb_params()['seed'] == 402
clf = xgb.XGBClassifier(seed=401)
assert clf.get_xgb_params()['seed'] == 401
def test_sklearn_n_jobs():
tm._skip_if_no_sklearn()
clf = xgb.XGBClassifier(n_jobs=1)
assert clf.get_xgb_params()['nthread'] == 1
clf = xgb.XGBClassifier(nthread=2)
assert clf.get_xgb_params()['nthread'] == 2
def test_kwargs():
tm._skip_if_no_sklearn()
params = {'updater': 'grow_gpu', 'subsample': .5, 'n_jobs': -1}
clf = xgb.XGBClassifier(n_estimators=1000, **params)
assert clf.get_params()['updater'] == 'grow_gpu'
assert clf.get_params()['subsample'] == .5
assert clf.get_params()['n_estimators'] == 1000
@raises(TypeError)
def test_kwargs_error():
tm._skip_if_no_sklearn()
params = {'updater': 'grow_gpu', 'subsample': .5, 'n_jobs': -1}
clf = xgb.XGBClassifier(n_jobs=1000, **params)
assert isinstance(clf, xgb.XGBClassifier)
def test_sklearn_clone():
tm._skip_if_no_sklearn()
from sklearn.base import clone
clf = xgb.XGBClassifier(n_jobs=2, nthread=3)
clf.n_jobs = -1
clone(clf)
def test_validation_weights_xgbmodel():
tm._skip_if_no_sklearn()
from sklearn.datasets import make_hastie_10_2
# prepare training and test data
X, y = make_hastie_10_2(n_samples=2000, random_state=42)
labels, y = np.unique(y, return_inverse=True)
X_train, X_test = X[:1600], X[1600:]
y_train, y_test = y[:1600], y[1600:]
# instantiate model
param_dist = {'objective': 'binary:logistic', 'n_estimators': 2,
'random_state': 123}
clf = xgb.sklearn.XGBModel(**param_dist)
# train it using instance weights only in the training set
weights_train = np.random.choice([1, 2], len(X_train))
clf.fit(X_train, y_train,
sample_weight=weights_train,
eval_set=[(X_test, y_test)],
eval_metric='logloss',
verbose=False)
# evaluate logloss metric on test set *without* using weights
evals_result_without_weights = clf.evals_result()
logloss_without_weights = evals_result_without_weights["validation_0"]["logloss"]
# now use weights for the test set
np.random.seed(0)
weights_test = np.random.choice([1, 2], len(X_test))
clf.fit(X_train, y_train,
sample_weight=weights_train,
eval_set=[(X_test, y_test)],
sample_weight_eval_set=[weights_test],
eval_metric='logloss',
verbose=False)
evals_result_with_weights = clf.evals_result()
logloss_with_weights = evals_result_with_weights["validation_0"]["logloss"]
# check that the logloss in the test set is actually different when using weights
# than when not using them
assert all((logloss_with_weights[i] != logloss_without_weights[i] for i in [0, 1]))
def test_validation_weights_xgbclassifier():
tm._skip_if_no_sklearn()
from sklearn.datasets import make_hastie_10_2
# prepare training and test data
X, y = make_hastie_10_2(n_samples=2000, random_state=42)
labels, y = np.unique(y, return_inverse=True)
X_train, X_test = X[:1600], X[1600:]
y_train, y_test = y[:1600], y[1600:]
# instantiate model
param_dist = {'objective': 'binary:logistic', 'n_estimators': 2,
'random_state': 123}
clf = xgb.sklearn.XGBClassifier(**param_dist)
# train it using instance weights only in the training set
weights_train = np.random.choice([1, 2], len(X_train))
clf.fit(X_train, y_train,
sample_weight=weights_train,
eval_set=[(X_test, y_test)],
eval_metric='logloss',
verbose=False)
# evaluate logloss metric on test set *without* using weights
evals_result_without_weights = clf.evals_result()
logloss_without_weights = evals_result_without_weights["validation_0"]["logloss"]
# now use weights for the test set
np.random.seed(0)
weights_test = np.random.choice([1, 2], len(X_test))
clf.fit(X_train, y_train,
sample_weight=weights_train,
eval_set=[(X_test, y_test)],
sample_weight_eval_set=[weights_test],
eval_metric='logloss',
verbose=False)
evals_result_with_weights = clf.evals_result()
logloss_with_weights = evals_result_with_weights["validation_0"]["logloss"]
# check that the logloss in the test set is actually different when using weights
# than when not using them
assert all((logloss_with_weights[i] != logloss_without_weights[i] for i in [0, 1]))
def test_save_load_model():
tm._skip_if_no_sklearn()
from sklearn.datasets import load_digits
try:
from sklearn.model_selection import KFold
except:
from sklearn.cross_validation import KFold
digits = load_digits(2)
y = digits['target']
X = digits['data']
try:
kf = KFold(y.shape[0], n_folds=2, shuffle=True, random_state=rng)
except TypeError: # sklearn.model_selection.KFold uses n_split
kf = KFold(
n_splits=2, shuffle=True, random_state=rng
).split(np.arange(y.shape[0]))
with TemporaryDirectory() as tempdir:
model_path = os.path.join(tempdir, 'digits.model')
for train_index, test_index in kf:
xgb_model = xgb.XGBClassifier().fit(X[train_index], y[train_index])
xgb_model.save_model(model_path)
xgb_model = xgb.XGBModel()
xgb_model.load_model(model_path)
preds = xgb_model.predict(X[test_index])
labels = y[test_index]
err = sum(1 for i in range(len(preds))
if int(preds[i] > 0.5) != labels[i]) / float(len(preds))
assert err < 0.1