xgboost/demo/guide-python/sklearn_evals_result.py
Jiaming Yuan c024c42dce
Modernize XGBoost Python document. (#7468)
* Use sphinx gallery to integrate examples.
* Remove mock objects.
* Add dask doc inventory.
2021-11-23 23:24:52 +08:00

45 lines
1.2 KiB
Python

"""
Demo for accessing the xgboost eval metrics by using sklearn interface
======================================================================
"""
import xgboost as xgb
import numpy as np
from sklearn.datasets import make_hastie_10_2
X, y = make_hastie_10_2(n_samples=2000, random_state=42)
# Map labels from {-1, 1} to {0, 1}
labels, y = np.unique(y, return_inverse=True)
X_train, X_test = X[:1600], X[1600:]
y_train, y_test = y[:1600], y[1600:]
param_dist = {'objective':'binary:logistic', 'n_estimators':2}
clf = xgb.XGBModel(**param_dist)
# Or you can use: clf = xgb.XGBClassifier(**param_dist)
clf.fit(X_train, y_train,
eval_set=[(X_train, y_train), (X_test, y_test)],
eval_metric='logloss',
verbose=True)
# Load evals result by calling the evals_result() function
evals_result = clf.evals_result()
print('Access logloss metric directly from validation_0:')
print(evals_result['validation_0']['logloss'])
print('')
print('Access metrics through a loop:')
for e_name, e_mtrs in evals_result.items():
print('- {}'.format(e_name))
for e_mtr_name, e_mtr_vals in e_mtrs.items():
print(' - {}'.format(e_mtr_name))
print(' - {}'.format(e_mtr_vals))
print('')
print('Access complete dict:')
print(evals_result)