python - Problems in LightGBM internals -
can't understand what's going on lightgbm (windows platform). had algorithm powerful, performance bad.
for comparison (default parameters in each algorithm) lightgbm performs according simple diff-metric = (actual - prediction):
- catboostregressor() - 18142884
- xgboostregressor() - 20235110
- gradientboostingregressor() - 20437130
- lgbmregressor() - 60296698 (version=2.0.5)
i trying find better parameters hyperopt, without success
lgbm_space = { 'type': 'lgbm', 'task': hp.choice('lgbm_task', ['train', 'prediction']), 'boosting_type': hp.choice('lgbm_boosting_type', ['gbdt', 'dart']), 'objective': hp.choice('lgbm_objective', ['regression']), 'n_estimators': hp.choice('lgbm_n_estimators', range(10, 201, 5)), 'learning_rate': hp.uniform('lgbm_learning_rate', 0.05, 1.0), 'num_leaves': hp.choice('lgbm_num_leaves', range(2, 7, 1)), 'tree_learner': hp.choice('lgbm_tree_learner', ['serial', 'feature', 'data']), 'metric': hp.choice('lgbm_metric', ['l1', 'l2', 'huber', 'fair']), 'huber_delta': hp.uniform('lgbm_huber_delta', 0.0, 1.0), 'fair_c': hp.uniform('lgbm_fair_c', 0.0, 1.0), 'max_depth': hp.choice('lgbm_max_depth', range(3, 11)), 'min_data_in_leaf': hp.choice('lgbm_min_data_in_leaf', range(0, 6, 1)), 'min_sum_hessian_in_leaf': hp.loguniform('lgbm_min_sum_hessian_in_leaf', -16, 5), 'feature_fraction': hp.uniform('lgbm_feature_fractionf', 0.0, 1.0), 'feature_fraction_seed': hp.choice('lgbm_feature_fraction_seed', [12345]), 'bagging_fraction': hp.uniform('lgbm_bagging_fraction', 0.0, 1.0), 'bagging_freq': hp.choice('lgbm_bagging_freq', range(0, 16, 1)), 'bagging_seed': hp.choice('lgbm_bagging_seed', [12345]), 'min_gain_to_split': hp.uniform('lgbm_min_gain_to_split', 0.0, 1.0), 'drop_rate': hp.uniform('lgbm_drop_rate', 0.0, 1.0), 'skip_drop': hp.uniform('lgbm_skip_drop', 0.0, 1.0), 'max_drop': hp.choice('lgbm_max_drop', [-1] + range(2, 51, 1)), 'drop_seed': hp.choice('lgbm_uniform_drop', [12345]), 'verbose': hp.choice('lgbm_verbose', [-1]), 'num_threads': hp.choice('lgbm_threads', [2]), } the best result 450422301, super bad in comparing above.
example of using scikit-learn api:
model = lgbmregressor() model.fit(x, y) model.predict(xt)
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