xgboost/tests/python/test_updaters.py

275 lines
10 KiB
Python

from random import choice
from string import ascii_lowercase
import testing as tm
import pytest
import xgboost as xgb
import numpy as np
from hypothesis import given, strategies, settings, note
exact_parameter_strategy = strategies.fixed_dictionaries({
'nthread': strategies.integers(1, 4),
'max_depth': strategies.integers(1, 11),
'min_child_weight': strategies.floats(0.5, 2.0),
'alpha': strategies.floats(0.0, 2.0),
'lambda': strategies.floats(1e-5, 2.0),
'eta': strategies.floats(0.01, 0.5),
'gamma': strategies.floats(0.0, 2.0),
'seed': strategies.integers(0, 10),
# We cannot enable subsampling as the training loss can increase
# 'subsample': strategies.floats(0.5, 1.0),
'colsample_bytree': strategies.floats(0.5, 1.0),
'colsample_bylevel': strategies.floats(0.5, 1.0),
})
hist_parameter_strategy = strategies.fixed_dictionaries({
'max_depth': strategies.integers(1, 11),
'max_leaves': strategies.integers(0, 1024),
'max_bin': strategies.integers(2, 512),
'grow_policy': strategies.sampled_from(['lossguide', 'depthwise']),
}).filter(lambda x: (x['max_depth'] > 0 or x['max_leaves'] > 0) and (
x['max_depth'] > 0 or x['grow_policy'] == 'lossguide'))
def train_result(param, dmat, num_rounds):
result = {}
xgb.train(param, dmat, num_rounds, [(dmat, 'train')], verbose_eval=False,
evals_result=result)
return result
class TestTreeMethod:
@given(exact_parameter_strategy, strategies.integers(1, 20),
tm.dataset_strategy)
@settings(deadline=None, print_blob=True)
def test_exact(self, param, num_rounds, dataset):
param['tree_method'] = 'exact'
param = dataset.set_params(param)
result = train_result(param, dataset.get_dmat(), num_rounds)
assert tm.non_increasing(result['train'][dataset.metric])
@given(
exact_parameter_strategy,
hist_parameter_strategy,
strategies.integers(1, 20),
tm.dataset_strategy,
)
@settings(deadline=None, print_blob=True)
def test_approx(self, param, hist_param, num_rounds, dataset):
param["tree_method"] = "approx"
param = dataset.set_params(param)
param.update(hist_param)
result = train_result(param, dataset.get_dmat(), num_rounds)
note(result)
assert tm.non_increasing(result["train"][dataset.metric])
@pytest.mark.skipif(**tm.no_sklearn())
def test_pruner(self):
import sklearn
params = {'tree_method': 'exact'}
cancer = sklearn.datasets.load_breast_cancer()
X = cancer['data']
y = cancer["target"]
dtrain = xgb.DMatrix(X, y)
booster = xgb.train(params, dtrain=dtrain, num_boost_round=10)
grown = str(booster.get_dump())
params = {'updater': 'prune', 'process_type': 'update', 'gamma': '0.2'}
booster = xgb.train(params, dtrain=dtrain, num_boost_round=10,
xgb_model=booster)
after_prune = str(booster.get_dump())
assert grown != after_prune
booster = xgb.train(params, dtrain=dtrain, num_boost_round=10,
xgb_model=booster)
second_prune = str(booster.get_dump())
# Second prune should not change the tree
assert after_prune == second_prune
@given(exact_parameter_strategy, hist_parameter_strategy, strategies.integers(1, 20),
tm.dataset_strategy)
@settings(deadline=None, print_blob=True)
def test_hist(self, param, hist_param, num_rounds, dataset):
param['tree_method'] = 'hist'
param = dataset.set_params(param)
param.update(hist_param)
result = train_result(param, dataset.get_dmat(), num_rounds)
note(result)
assert tm.non_increasing(result['train'][dataset.metric])
def test_hist_categorical(self):
# hist must be same as exact on all-categorial data
dpath = 'demo/data/'
ag_dtrain = xgb.DMatrix(dpath + 'agaricus.txt.train')
ag_dtest = xgb.DMatrix(dpath + 'agaricus.txt.test')
ag_param = {'max_depth': 2,
'tree_method': 'hist',
'eta': 1,
'verbosity': 0,
'objective': 'binary:logistic',
'eval_metric': 'auc'}
hist_res = {}
exact_res = {}
xgb.train(ag_param, ag_dtrain, 10,
[(ag_dtrain, 'train'), (ag_dtest, 'test')],
evals_result=hist_res)
ag_param["tree_method"] = "exact"
xgb.train(ag_param, ag_dtrain, 10,
[(ag_dtrain, 'train'), (ag_dtest, 'test')],
evals_result=exact_res)
assert hist_res['train']['auc'] == exact_res['train']['auc']
assert hist_res['test']['auc'] == exact_res['test']['auc']
@pytest.mark.skipif(**tm.no_sklearn())
def test_hist_degenerate_case(self):
# Test a degenerate case where the quantile sketcher won't return any
# quantile points for a particular feature (the second feature in
# this example). Source: https://github.com/dmlc/xgboost/issues/2943
nan = np.nan
param = {'missing': nan, 'tree_method': 'hist'}
model = xgb.XGBRegressor(**param)
X = np.array([[6.18827160e+05, 1.73000000e+02], [6.37345679e+05, nan],
[6.38888889e+05, nan], [6.28086420e+05, nan]])
y = [1000000., 0., 0., 500000.]
w = [0, 0, 1, 0]
model.fit(X, y, sample_weight=w)
def run_invalid_category(self, tree_method: str) -> None:
rng = np.random.default_rng()
# too large
X = rng.integers(low=0, high=4, size=1000).reshape(100, 10)
y = rng.normal(loc=0, scale=1, size=100)
X[13, 7] = np.iinfo(np.int32).max + 1
# Check is performed during sketching.
Xy = xgb.DMatrix(X, y, feature_types=["c"] * 10)
with pytest.raises(ValueError):
xgb.train({"tree_method": tree_method}, Xy)
X[13, 7] = 16777216
Xy = xgb.DMatrix(X, y, feature_types=["c"] * 10)
with pytest.raises(ValueError):
xgb.train({"tree_method": tree_method}, Xy)
# mixed positive and negative values
X = rng.normal(loc=0, scale=1, size=1000).reshape(100, 10)
y = rng.normal(loc=0, scale=1, size=100)
Xy = xgb.DMatrix(X, y, feature_types=["c"] * 10)
with pytest.raises(ValueError):
xgb.train({"tree_method": tree_method}, Xy)
if tree_method == "gpu_hist":
import cupy as cp
X, y = cp.array(X), cp.array(y)
with pytest.raises(ValueError):
Xy = xgb.DeviceQuantileDMatrix(X, y, feature_types=["c"] * 10)
def test_invalid_category(self) -> None:
self.run_invalid_category("approx")
self.run_invalid_category("hist")
def run_max_cat(self, tree_method: str) -> None:
"""Test data with size smaller than number of categories."""
import pandas as pd
n_cat = 100
n = 5
X = pd.Series(
["".join(choice(ascii_lowercase) for i in range(3)) for i in range(n_cat)],
dtype="category",
)[:n].to_frame()
reg = xgb.XGBRegressor(
enable_categorical=True,
tree_method=tree_method,
n_estimators=10,
)
y = pd.Series(range(n))
reg.fit(X=X, y=y, eval_set=[(X, y)])
assert tm.non_increasing(reg.evals_result()["validation_0"]["rmse"])
@pytest.mark.parametrize("tree_method", ["hist", "approx"])
def test_max_cat(self, tree_method) -> None:
self.run_max_cat(tree_method)
def run_categorical_basic(self, rows, cols, rounds, cats, tree_method):
onehot, label = tm.make_categorical(rows, cols, cats, True)
cat, _ = tm.make_categorical(rows, cols, cats, False)
by_etl_results = {}
by_builtin_results = {}
predictor = "gpu_predictor" if tree_method == "gpu_hist" else None
# Use one-hot exclusively
parameters = {
"tree_method": tree_method, "predictor": predictor, "max_cat_to_onehot": 9999
}
m = xgb.DMatrix(onehot, label, enable_categorical=False)
xgb.train(
parameters,
m,
num_boost_round=rounds,
evals=[(m, "Train")],
evals_result=by_etl_results,
)
m = xgb.DMatrix(cat, label, enable_categorical=True)
xgb.train(
parameters,
m,
num_boost_round=rounds,
evals=[(m, "Train")],
evals_result=by_builtin_results,
)
# There are guidelines on how to specify tolerance based on considering output as
# random variables. But in here the tree construction is extremely sensitive to
# floating point errors. An 1e-5 error in a histogram bin can lead to an entirely
# different tree. So even though the test is quite lenient, hypothesis can still
# pick up falsifying examples from time to time.
np.testing.assert_allclose(
np.array(by_etl_results["Train"]["rmse"]),
np.array(by_builtin_results["Train"]["rmse"]),
rtol=1e-3,
)
assert tm.non_increasing(by_builtin_results["Train"]["rmse"])
by_grouping: xgb.callback.TrainingCallback.EvalsLog = {}
parameters["max_cat_to_onehot"] = 1
parameters["reg_lambda"] = 0
m = xgb.DMatrix(cat, label, enable_categorical=True)
xgb.train(
parameters,
m,
num_boost_round=rounds,
evals=[(m, "Train")],
evals_result=by_grouping,
)
rmse_oh = by_builtin_results["Train"]["rmse"]
rmse_group = by_grouping["Train"]["rmse"]
# always better or equal to onehot when there's no regularization.
for a, b in zip(rmse_oh, rmse_group):
assert a >= b
parameters["reg_lambda"] = 1.0
by_grouping = {}
xgb.train(
parameters,
m,
num_boost_round=32,
evals=[(m, "Train")],
evals_result=by_grouping,
)
assert tm.non_increasing(by_grouping["Train"]["rmse"]), by_grouping
@given(strategies.integers(10, 400), strategies.integers(3, 8),
strategies.integers(1, 2), strategies.integers(4, 7))
@settings(deadline=None, print_blob=True)
@pytest.mark.skipif(**tm.no_pandas())
def test_categorical(self, rows, cols, rounds, cats):
self.run_categorical_basic(rows, cols, rounds, cats, "approx")
self.run_categorical_basic(rows, cols, rounds, cats, "hist")