⚫ lambda_l1/lambda_l2: trial.suggest_loguniform('lambda_l1', 1e-8, 10.0) ⚫ num_leaves: trial.suggest_loguniform('lambda_l2', 1e-8, 10.0) ⚫ min_child_samples: trial.suggest_int('num_leaves', 2, 2 ** max_depth) ⚫ bagging_fraction: min(trial.suggest_uniform('bagging_fraction', 0.4, 1.0 + EPS), 1.0) ⚫ bagging_freq: trial.suggest_int('bagging_freq', 1, 7) 注) maxdepth = 8, EPS=1e-12 https://github.com/optuna/optuna/blob/master/optuna/integration/lightgbm_tuner/optimize.py#L201-L225