Rework the MAP metric. (#8931)

- The new implementation is more strict as only binary labels are accepted. The previous implementation converts values greater than 1 to 1.
- Deterministic GPU. (no atomic add).
- Fix top-k handling.
- Precise definition of MAP. (There are other variants on how to handle top-k).
- Refactor GPU ranking tests.
This commit is contained in:
Jiaming Yuan
2023-03-22 17:45:20 +08:00
committed by GitHub
parent b240f055d3
commit 5891f752c8
18 changed files with 458 additions and 323 deletions

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@@ -177,4 +177,36 @@ TEST(NDCGCache, InitFromCPU) {
Context ctx;
TestNDCGCache(&ctx);
}
void TestMAPCache(Context const* ctx) {
auto p_fmat = EmptyDMatrix();
MetaInfo& info = p_fmat->Info();
LambdaRankParam param;
param.UpdateAllowUnknown(Args{});
std::vector<float> h_data(32);
common::Iota(ctx, h_data.begin(), h_data.end(), 0.0f);
info.labels.Reshape(h_data.size());
info.num_row_ = h_data.size();
info.labels.Data()->HostVector() = std::move(h_data);
auto fail = [&]() { std::make_shared<MAPCache>(ctx, info, param); };
// binary label
ASSERT_THROW(fail(), dmlc::Error);
h_data = std::vector<float>(32, 0.0f);
h_data[1] = 1.0f;
info.labels.Data()->HostVector() = h_data;
auto p_cache = std::make_shared<MAPCache>(ctx, info, param);
ASSERT_EQ(p_cache->Acc(ctx).size(), info.num_row_);
ASSERT_EQ(p_cache->NumRelevant(ctx).size(), info.num_row_);
}
TEST(MAPCache, InitFromCPU) {
Context ctx;
ctx.Init(Args{});
TestMAPCache(&ctx);
}
} // namespace xgboost::ltr

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@@ -95,4 +95,10 @@ TEST(NDCGCache, InitFromGPU) {
ctx.UpdateAllowUnknown(Args{{"gpu_id", "0"}});
TestNDCGCache(&ctx);
}
TEST(MAPCache, InitFromGPU) {
Context ctx;
ctx.UpdateAllowUnknown(Args{{"gpu_id", "0"}});
TestMAPCache(&ctx);
}
} // namespace xgboost::ltr

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@@ -6,4 +6,6 @@
namespace xgboost::ltr {
void TestNDCGCache(Context const* ctx);
void TestMAPCache(Context const* ctx);
} // namespace xgboost::ltr

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@@ -141,7 +141,7 @@ TEST(Metric, DeclareUnifiedTest(MAP)) {
// Rank metric with group info
EXPECT_NEAR(GetMetricEval(metric,
{0.1f, 0.9f, 0.2f, 0.8f, 0.4f, 1.7f},
{2, 7, 1, 0, 5, 0}, // Labels
{1, 1, 1, 0, 1, 0}, // Labels
{}, // Weights
{0, 2, 5, 6}), // Group info
0.8611f, 0.001f);

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@@ -1,194 +1,130 @@
import itertools
import os
import shutil
import urllib.request
import zipfile
from typing import Dict
import numpy as np
import pytest
import xgboost
from xgboost import testing as tm
pytestmark = tm.timeout(10)
pytestmark = tm.timeout(30)
class TestRanking:
@classmethod
def setup_class(cls):
"""
Download and setup the test fixtures
"""
from sklearn.datasets import load_svmlight_files
def comp_training_with_rank_objective(
dtrain: xgboost.DMatrix,
dtest: xgboost.DMatrix,
rank_objective: str,
metric_name: str,
tolerance: float = 1e-02,
) -> None:
"""Internal method that trains the dataset using the rank objective on GPU and CPU,
evaluates the metric and determines if the delta between the metric is within the
tolerance level.
# download the test data
cls.dpath = os.path.join(tm.demo_dir(__file__), "rank/")
src = 'https://s3-us-west-2.amazonaws.com/xgboost-examples/MQ2008.zip'
target = os.path.join(cls.dpath, "MQ2008.zip")
"""
# specify validations set to watch performance
watchlist = [(dtest, "eval"), (dtrain, "train")]
if os.path.exists(cls.dpath) and os.path.exists(target):
print("Skipping dataset download...")
else:
urllib.request.urlretrieve(url=src, filename=target)
with zipfile.ZipFile(target, 'r') as f:
f.extractall(path=cls.dpath)
params = {
"booster": "gbtree",
"tree_method": "gpu_hist",
"gpu_id": 0,
"predictor": "gpu_predictor",
}
(x_train, y_train, qid_train, x_test, y_test, qid_test,
x_valid, y_valid, qid_valid) = load_svmlight_files(
(cls.dpath + "MQ2008/Fold1/train.txt",
cls.dpath + "MQ2008/Fold1/test.txt",
cls.dpath + "MQ2008/Fold1/vali.txt"),
query_id=True, zero_based=False)
# instantiate the matrices
cls.dtrain = xgboost.DMatrix(x_train, y_train)
cls.dvalid = xgboost.DMatrix(x_valid, y_valid)
cls.dtest = xgboost.DMatrix(x_test, y_test)
# set the group counts from the query IDs
cls.dtrain.set_group([len(list(items))
for _key, items in itertools.groupby(qid_train)])
cls.dtest.set_group([len(list(items))
for _key, items in itertools.groupby(qid_test)])
cls.dvalid.set_group([len(list(items))
for _key, items in itertools.groupby(qid_valid)])
# save the query IDs for testing
cls.qid_train = qid_train
cls.qid_test = qid_test
cls.qid_valid = qid_valid
num_trees = 100
check_metric_improvement_rounds = 10
def setup_weighted(x, y, groups):
# Setup weighted data
data = xgboost.DMatrix(x, y)
groups_segment = [len(list(items))
for _key, items in itertools.groupby(groups)]
data.set_group(groups_segment)
n_groups = len(groups_segment)
weights = np.ones((n_groups,))
data.set_weight(weights)
return data
evals_result: Dict[str, Dict] = {}
params["objective"] = rank_objective
params["eval_metric"] = metric_name
bst = xgboost.train(
params,
dtrain,
num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist,
evals_result=evals_result,
)
gpu_scores = evals_result["train"][metric_name][-1]
cls.dtrain_w = setup_weighted(x_train, y_train, qid_train)
cls.dtest_w = setup_weighted(x_test, y_test, qid_test)
cls.dvalid_w = setup_weighted(x_valid, y_valid, qid_valid)
evals_result = {}
# model training parameters
cls.params = {'booster': 'gbtree',
'tree_method': 'gpu_hist',
'gpu_id': 0,
'predictor': 'gpu_predictor'}
cls.cpu_params = {'booster': 'gbtree',
'tree_method': 'hist',
'gpu_id': -1,
'predictor': 'cpu_predictor'}
cpu_params = {
"booster": "gbtree",
"tree_method": "hist",
"gpu_id": -1,
"predictor": "cpu_predictor",
}
cpu_params["objective"] = rank_objective
cpu_params["eval_metric"] = metric_name
bstc = xgboost.train(
cpu_params,
dtrain,
num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist,
evals_result=evals_result,
)
cpu_scores = evals_result["train"][metric_name][-1]
@classmethod
def teardown_class(cls):
"""
Cleanup test artifacts from download and unpacking
:return:
"""
os.remove(os.path.join(cls.dpath, "MQ2008.zip"))
shutil.rmtree(os.path.join(cls.dpath, "MQ2008"))
info = (rank_objective, metric_name)
assert np.allclose(gpu_scores, cpu_scores, tolerance, tolerance), info
assert np.allclose(bst.best_score, bstc.best_score, tolerance, tolerance), info
@classmethod
def __test_training_with_rank_objective(cls, rank_objective, metric_name, tolerance=1e-02):
"""
Internal method that trains the dataset using the rank objective on GPU and CPU, evaluates
the metric and determines if the delta between the metric is within the tolerance level
:return:
"""
# specify validations set to watch performance
watchlist = [(cls.dtest, 'eval'), (cls.dtrain, 'train')]
evals_result_weighted: Dict[str, Dict] = {}
dtest.set_weight(np.ones((dtest.get_group().size,)))
dtrain.set_weight(np.ones((dtrain.get_group().size,)))
watchlist = [(dtest, "eval"), (dtrain, "train")]
bst_w = xgboost.train(
params,
dtrain,
num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist,
evals_result=evals_result_weighted,
)
weighted_metric = evals_result_weighted["train"][metric_name][-1]
num_trees = 100
check_metric_improvement_rounds = 10
tolerance = 1e-5
assert np.allclose(bst_w.best_score, bst.best_score, tolerance, tolerance)
assert np.allclose(weighted_metric, gpu_scores, tolerance, tolerance)
evals_result = {}
cls.params['objective'] = rank_objective
cls.params['eval_metric'] = metric_name
bst = xgboost.train(
cls.params, cls.dtrain, num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist, evals_result=evals_result)
gpu_map_metric = evals_result['train'][metric_name][-1]
evals_result = {}
cls.cpu_params['objective'] = rank_objective
cls.cpu_params['eval_metric'] = metric_name
bstc = xgboost.train(
cls.cpu_params, cls.dtrain, num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist, evals_result=evals_result)
cpu_map_metric = evals_result['train'][metric_name][-1]
@pytest.mark.parametrize(
"objective,metric",
[
("rank:pairwise", "auc"),
("rank:pairwise", "ndcg"),
("rank:pairwise", "map"),
("rank:ndcg", "auc"),
("rank:ndcg", "ndcg"),
("rank:ndcg", "map"),
("rank:map", "auc"),
("rank:map", "ndcg"),
("rank:map", "map"),
],
)
def test_with_mq2008(objective, metric) -> None:
(
x_train,
y_train,
qid_train,
x_test,
y_test,
qid_test,
x_valid,
y_valid,
qid_valid,
) = tm.get_mq2008(os.path.join(os.path.join(tm.demo_dir(__file__), "rank")))
assert np.allclose(gpu_map_metric, cpu_map_metric, tolerance,
tolerance)
assert np.allclose(bst.best_score, bstc.best_score, tolerance,
tolerance)
if metric.find("map") != -1 or objective.find("map") != -1:
y_train[y_train <= 1] = 0.0
y_train[y_train > 1] = 1.0
y_test[y_test <= 1] = 0.0
y_test[y_test > 1] = 1.0
evals_result_weighted = {}
watchlist = [(cls.dtest_w, 'eval'), (cls.dtrain_w, 'train')]
bst_w = xgboost.train(
cls.params, cls.dtrain_w, num_boost_round=num_trees,
early_stopping_rounds=check_metric_improvement_rounds,
evals=watchlist, evals_result=evals_result_weighted)
weighted_metric = evals_result_weighted['train'][metric_name][-1]
# GPU Ranking is not deterministic due to `AtomicAddGpair`,
# remove tolerance once the issue is resolved.
# https://github.com/dmlc/xgboost/issues/5561
assert np.allclose(bst_w.best_score, bst.best_score,
tolerance, tolerance)
assert np.allclose(weighted_metric, gpu_map_metric,
tolerance, tolerance)
dtrain = xgboost.DMatrix(x_train, y_train, qid=qid_train)
dtest = xgboost.DMatrix(x_test, y_test, qid=qid_test)
def test_training_rank_pairwise_map_metric(self):
"""
Train an XGBoost ranking model with pairwise objective function and compare map metric
"""
self.__test_training_with_rank_objective('rank:pairwise', 'map')
def test_training_rank_pairwise_auc_metric(self):
"""
Train an XGBoost ranking model with pairwise objective function and compare auc metric
"""
self.__test_training_with_rank_objective('rank:pairwise', 'auc')
def test_training_rank_pairwise_ndcg_metric(self):
"""
Train an XGBoost ranking model with pairwise objective function and compare ndcg metric
"""
self.__test_training_with_rank_objective('rank:pairwise', 'ndcg')
def test_training_rank_ndcg_map(self):
"""
Train an XGBoost ranking model with ndcg objective function and compare map metric
"""
self.__test_training_with_rank_objective('rank:ndcg', 'map')
def test_training_rank_ndcg_auc(self):
"""
Train an XGBoost ranking model with ndcg objective function and compare auc metric
"""
self.__test_training_with_rank_objective('rank:ndcg', 'auc')
def test_training_rank_ndcg_ndcg(self):
"""
Train an XGBoost ranking model with ndcg objective function and compare ndcg metric
"""
self.__test_training_with_rank_objective('rank:ndcg', 'ndcg')
def test_training_rank_map_map(self):
"""
Train an XGBoost ranking model with map objective function and compare map metric
"""
self.__test_training_with_rank_objective('rank:map', 'map')
def test_training_rank_map_auc(self):
"""
Train an XGBoost ranking model with map objective function and compare auc metric
"""
self.__test_training_with_rank_objective('rank:map', 'auc')
def test_training_rank_map_ndcg(self):
"""
Train an XGBoost ranking model with map objective function and compare ndcg metric
"""
self.__test_training_with_rank_objective('rank:map', 'ndcg')
comp_training_with_rank_objective(dtrain, dtest, objective, metric)

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@@ -128,12 +128,23 @@ def test_ranking():
x_test = np.random.rand(100, 10)
params = {'tree_method': 'exact', 'objective': 'rank:pairwise',
'learning_rate': 0.1, 'gamma': 1.0, 'min_child_weight': 0.1,
'max_depth': 6, 'n_estimators': 4}
params = {
"tree_method": "exact",
"learning_rate": 0.1,
"gamma": 1.0,
"min_child_weight": 0.1,
"max_depth": 6,
"eval_metric": "ndcg",
"n_estimators": 4,
}
model = xgb.sklearn.XGBRanker(**params)
model.fit(x_train, y_train, group=train_group,
eval_set=[(x_valid, y_valid)], eval_group=[valid_group])
model.fit(
x_train,
y_train,
group=train_group,
eval_set=[(x_valid, y_valid)],
eval_group=[valid_group],
)
assert model.evals_result()
pred = model.predict(x_test)
@@ -145,11 +156,18 @@ def test_ranking():
assert train_data.get_label().shape[0] == x_train.shape[0]
valid_data.set_group(valid_group)
params_orig = {'tree_method': 'exact', 'objective': 'rank:pairwise',
'eta': 0.1, 'gamma': 1.0,
'min_child_weight': 0.1, 'max_depth': 6}
xgb_model_orig = xgb.train(params_orig, train_data, num_boost_round=4,
evals=[(valid_data, 'validation')])
params_orig = {
"tree_method": "exact",
"objective": "rank:pairwise",
"eta": 0.1,
"gamma": 1.0,
"min_child_weight": 0.1,
"max_depth": 6,
"eval_metric": "ndcg",
}
xgb_model_orig = xgb.train(
params_orig, train_data, num_boost_round=4, evals=[(valid_data, "validation")]
)
pred_orig = xgb_model_orig.predict(test_data)
np.testing.assert_almost_equal(pred, pred_orig)
@@ -165,7 +183,11 @@ def test_ranking_metric() -> None:
# sklearn compares the number of mis-classified docs, while the one in xgboost
# compares the number of mis-classified pairs.
ltr = xgb.XGBRanker(
eval_metric=roc_auc_score, n_estimators=10, tree_method="hist", max_depth=2
eval_metric=roc_auc_score,
n_estimators=10,
tree_method="hist",
max_depth=2,
objective="rank:pairwise",
)
ltr.fit(
X,