获取叶节点索引的演示

import os

import xgboost as xgb

# load data in do training
CURRENT_DIR = os.path.dirname(__file__)
dtrain = xgb.DMatrix(
    os.path.join(CURRENT_DIR, "../data/agaricus.txt.train?format=libsvm")
)
dtest = xgb.DMatrix(
    os.path.join(CURRENT_DIR, "../data/agaricus.txt.test?format=libsvm")
)
param = {"max_depth": 2, "eta": 1, "objective": "binary:logistic"}
watchlist = [(dtest, "eval"), (dtrain, "train")]
num_round = 3
bst = xgb.train(param, dtrain, num_round, watchlist)

print("start testing predict the leaf indices")
# predict using first 2 tree
leafindex = bst.predict(
    dtest, iteration_range=(0, 2), pred_leaf=True, strict_shape=True
)
print(leafindex.shape)
print(leafindex)
# predict all trees
leafindex = bst.predict(dtest, pred_leaf=True)
print(leafindex.shape)