def process(b: int):
# sample bootstrap from batch logged bandit feedback
boot_bandit_feedback = obd.sample_bootstrap_bandit_feedback(
test_size=test_size, is_timeseries_split=True, random_state=b
)
# train an evaluation on the training set of the logged bandit feedback data
action_dist = counterfactual_policy.fit(
context=boot_bandit_feedback["context"],
action=boot_bandit_feedback["action"],
reward=boot_bandit_feedback["reward"],
pscore=boot_bandit_feedback["pscore"],
position=boot_bandit_feedback["position"],
)
# make action selections (predictions)
action_dist = counterfactual_policy.predict(
context=boot_bandit_feedback["context_test"]
)
# estimate the policy value of a given counterfactual algorithm by the three OPE estimators.
ipw = InverseProbabilityWeighting()
return ipw.estimate_policy_value(
reward=boot_bandit_feedback["reward_test"],
action=boot_bandit_feedback["action_test"],
position=boot_bandit_feedback["position_test"],
pscore=boot_bandit_feedback["pscore_test"],
action_dist=action_dist,
)
def test_ipw_init_using_invalid_inputs(
lambda_,
use_estimated_pscore,
err,
description,
):
with pytest.raises(err, match=f"{description}*"):
_ = InverseProbabilityWeighting(
lambda_=lambda_, use_estimated_pscore=use_estimated_pscore
)
def test_ipw_using_random_evaluation_policy(
synthetic_bandit_feedback: BanditFeedback, random_action_dist: np.ndarray
) -> None:
"""
Test the format of ipw variants using synthetic bandit data and random evaluation policy
"""
action_dist = random_action_dist
# prepare input dict
input_dict = {
k: v
for k, v in synthetic_bandit_feedback.items()
if k in ["reward", "action", "pscore", "position"]
}
input_dict["action_dist"] = action_dist
# ipw estimators can be used without estimated_rewards_by_reg_model
for estimator in [ipw, snipw, ipw_tuning_mse, ipw_tuning_slope]:
estimated_policy_value = estimator.estimate_policy_value(**input_dict)
assert isinstance(
estimated_policy_value, float
), f"invalid type response: {estimator}"
# ipw with estimated pscore
ipw_estimated_pscore = InverseProbabilityWeighting(use_estimated_pscore=True)
snipw_estimated_pscore = SelfNormalizedInverseProbabilityWeighting(
use_estimated_pscore=True
)
ipw_tuning_estimated_pscore = InverseProbabilityWeightingTuning(
lambdas=[10, 1000], use_estimated_pscore=True
)
input_dict["estimated_pscore"] = input_dict["pscore"]
del input_dict["pscore"]
for estimator in [
ipw_estimated_pscore,
snipw_estimated_pscore,
ipw_tuning_estimated_pscore,
]:
estimated_policy_value = estimator.estimate_policy_value(**input_dict)
assert isinstance(
estimated_policy_value, float
), f"invalid type response: {estimator}"
# remove necessary keys
del input_dict["reward"]
del input_dict["action"]
for estimator in [ipw, snipw]:
with pytest.raises(
TypeError,
match=re.escape(
"estimate_policy_value() missing 2 required positional arguments: 'reward' and 'action'"
),
):
_ = estimator.estimate_policy_value(**input_dict)
# hyperparameter for the regression model used in model dependent OPE estimators
with open("./conf/hyperparams.yaml", "rb") as f:
hyperparams = yaml.safe_load(f)
base_model_dict = dict(
logistic_regression=LogisticRegression,
lightgbm=HistGradientBoostingClassifier,
random_forest=RandomForestClassifier,
)
# compared OPE estimators
ope_estimators = [
DirectMethod(),
InverseProbabilityWeighting(),
SelfNormalizedInverseProbabilityWeighting(),
DoublyRobust(),
SelfNormalizedDoublyRobust(),
SwitchDoublyRobust(tau=1.0, estimator_name="switch-dr (tau=1)"),
SwitchDoublyRobust(tau=100.0, estimator_name="switch-dr (tau=100)"),
DoublyRobustWithShrinkage(lambda_=1.0, estimator_name="dr-os (lambda=1)"),
DoublyRobustWithShrinkage(lambda_=100.0, estimator_name="dr-os (lambda=100)"),
]
if __name__ == "__main__":
parser = argparse.ArgumentParser(
description="evaluate off-policy estimators with synthetic bandit data."
)
parser.add_argument(
"--n_runs", type=int, default=1, help="number of simulations in the experiment."
data_path = Path("../open_bandit_dataset")
obd = OpenBanditDataset(
behavior_policy=behavior_policy, campaign=campaign, data_path=data_path
)
# hyparparameters for counterfactual policies
kwargs = dict(
n_actions=obd.n_actions, len_list=obd.len_list, random_state=random_state
)
if counterfactual_policy == "bts":
kwargs["alpha"] = production_prior_for_bts[campaign]["alpha"]
kwargs["beta"] = production_prior_for_bts[campaign]["beta"]
kwargs["batch_size"] = production_batch_size_for_bts[campaign]
policy = counterfactual_policy_dict[counterfactual_policy](**kwargs)
# compared OPE estimators
ope_estimators = [DirectMethod(), InverseProbabilityWeighting(), DoublyRobust()]
# a base ML model for regression model used in Direct Method and Doubly Robust
base_model = CalibratedClassifierCV(LogisticRegression(**hyperparams))
# ground-truth policy value of a counterfactual policy
# , which is estimated with factual (observed) rewards (on-policy estimation)
ground_truth_policy_value = OpenBanditDataset.calc_on_policy_policy_value_estimate(
behavior_policy=counterfactual_policy, campaign=campaign, data_path=data_path
)
evaluation_of_ope_results = {
est.estimator_name: np.zeros(n_boot_samples) for est in ope_estimators
}
for b in np.arange(n_boot_samples):
# sample bootstrap from batch logged bandit feedback
boot_bandit_feedback = obd.sample_bootstrap_bandit_feedback(random_state=b)
# run a counterfactual bandit algorithm on logged bandit feedback data
def test_ipw_using_invalid_input_data(
action_dist: np.ndarray,
action: np.ndarray,
reward: np.ndarray,
pscore: np.ndarray,
position: np.ndarray,
use_estimated_pscore: bool,
estimated_pscore: np.ndarray,
description: str,
) -> None:
# prepare ipw instances
ipw = InverseProbabilityWeighting(use_estimated_pscore=use_estimated_pscore)
snipw = SelfNormalizedInverseProbabilityWeighting(
use_estimated_pscore=use_estimated_pscore
)
sgipw = SubGaussianInverseProbabilityWeighting(
use_estimated_pscore=use_estimated_pscore
)
ipw_tuning = InverseProbabilityWeightingTuning(
lambdas=[10, 1000], use_estimated_pscore=use_estimated_pscore
)
sgipw_tuning = SubGaussianInverseProbabilityWeightingTuning(
lambdas=[0.01, 0.1], use_estimated_pscore=use_estimated_pscore
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = ipw.estimate_policy_value(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = ipw.estimate_interval(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = snipw.estimate_policy_value(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = snipw.estimate_interval(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = ipw_tuning.estimate_policy_value(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = ipw_tuning.estimate_interval(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = sgipw.estimate_policy_value(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = sgipw.estimate_interval(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = sgipw_tuning.estimate_policy_value(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
with pytest.raises(ValueError, match=f"{description}*"):
_ = sgipw_tuning.estimate_interval(
action_dist=action_dist,
action=action,
reward=reward,
pscore=pscore,
position=position,
estimated_pscore=estimated_pscore,
)
def main(cfg: DictConfig) -> None:
print(cfg)
logger.info(f"The current working directory is {Path().cwd()}")
start_time = time.time()
logger.info("initializing experimental condition..")
# compared ope estimators
lambdas = list(dict(cfg.estimator_hyperparams)["lambdas"])
ope_estimators = [
InverseProbabilityWeighting(estimator_name="IPW"),
SelfNormalizedInverseProbabilityWeighting(estimator_name="SNIPW"),
DirectMethod(estimator_name="DM"),
DoublyRobust(estimator_name="DR"),
SelfNormalizedDoublyRobust(estimator_name="SNDR"),
SwitchDoublyRobustTuning(lambdas=lambdas, estimator_name="Switch-DR"),
DoublyRobustWithShrinkageTuning(lambdas=lambdas,
estimator_name="DRos"),
]
# configurations
n_seeds = cfg.setting.n_seeds
sample_size = cfg.setting.sample_size
reg_model = cfg.setting.reg_model
campaign = cfg.setting.campaign
behavior_policy = cfg.setting.behavior_policy
test_size = cfg.setting.test_size
is_timeseries_split = cfg.setting.is_timeseries_split
n_folds = cfg.setting.n_folds
obd_path = (Path().cwd().parents[5] /
"open_bandit_dataset" if cfg.setting.is_full_obd else None)
random_state = cfg.setting.random_state
np.random.seed(random_state)
# define dataset
dataset_ts = OpenBanditDataset(behavior_policy="bts",
campaign=campaign,
data_path=obd_path)
dataset_ur = OpenBanditDataset(behavior_policy="random",
campaign=campaign,
data_path=obd_path)
# prepare logged bandit feedback and evaluation policies
if behavior_policy == "random":
if is_timeseries_split:
bandit_feedback_ur = dataset_ur.obtain_batch_bandit_feedback(
test_size=test_size,
is_timeseries_split=True,
)[0]
else:
bandit_feedback_ur = dataset_ur.obtain_batch_bandit_feedback()
bandit_feedbacks = [bandit_feedback_ur]
# obtain the ground-truth policy value
ground_truth_ts = OpenBanditDataset.calc_on_policy_policy_value_estimate(
behavior_policy="bts",
campaign=campaign,
data_path=obd_path,
test_size=test_size,
is_timeseries_split=is_timeseries_split,
)
# obtain action choice probabilities and define evaluation policies
policy_ts = BernoulliTS(
n_actions=dataset_ts.n_actions,
len_list=dataset_ts.len_list,
random_state=random_state,
is_zozotown_prior=True,
campaign=campaign,
)
action_dist_ts = policy_ts.compute_batch_action_dist(n_rounds=1000000)
evaluation_policies = [(ground_truth_ts, action_dist_ts)]
else:
if is_timeseries_split:
bandit_feedback_ts = dataset_ts.obtain_batch_bandit_feedback(
test_size=test_size,
is_timeseries_split=True,
)[0]
else:
bandit_feedback_ts = dataset_ts.obtain_batch_bandit_feedback()
bandit_feedbacks = [bandit_feedback_ts]
# obtain the ground-truth policy value
ground_truth_ur = OpenBanditDataset.calc_on_policy_policy_value_estimate(
behavior_policy="random",
campaign=campaign,
data_path=obd_path,
test_size=test_size,
is_timeseries_split=is_timeseries_split,
)
# obtain action choice probabilities and define evaluation policies
policy_ur = Random(
n_actions=dataset_ur.n_actions,
len_list=dataset_ur.len_list,
random_state=random_state,
)
action_dist_ur = policy_ur.compute_batch_action_dist(n_rounds=1000000)
evaluation_policies = [(ground_truth_ur, action_dist_ur)]
# regression models used in ope estimators
hyperparams = dict(cfg.reg_model_hyperparams)[reg_model]
regression_models = [reg_model_dict[reg_model](**hyperparams)]
# define an evaluator class
evaluator = InterpretableOPEEvaluator(
random_states=np.arange(n_seeds),
bandit_feedbacks=bandit_feedbacks,
evaluation_policies=evaluation_policies,
ope_estimators=ope_estimators,
regression_models=regression_models,
)
# conduct an evaluation of OPE experiment
logger.info("experiment started")
_ = evaluator.estimate_policy_value(sample_size=sample_size,
n_folds_=n_folds)
# calculate statistics
mean = evaluator.calculate_mean(root=True)
mean_scaled = evaluator.calculate_mean(scale=True, root=True)
# save results of the evaluation of off-policy estimators
log_path = Path("./outputs")
log_path.mkdir(exist_ok=True, parents=True)
# save root mse
root_mse_df = DataFrame()
root_mse_df["estimator"] = list(mean.keys())
root_mse_df["mean"] = list(mean.values())
root_mse_df["mean(scaled)"] = list(mean_scaled.values())
root_mse_df.to_csv(log_path / "root_mse.csv")
# conduct pairwise t-tests
se_df = DataFrame(evaluator.calculate_squared_error())
se_df = DataFrame(se_df.stack()).reset_index(1)
se_df.rename(columns={"level_1": "estimators", 0: "se"}, inplace=True)
nonparam_ttests = (pg.pairwise_ttests(
data=se_df,
dv="se",
parametric=False,
between="estimators",
).round(4).drop(["Contrast", "Parametric", "Paired"], axis=1))
nonparam_ttests.to_csv(log_path / "nonparam_ttests.csv")
# save reg model metrics
DataFrame(evaluator.reg_model_metrics).describe().to_csv(
log_path / "reg_model_metrics.csv")
# print result
print(root_mse_df)
experiment = f"{campaign}-{behavior_policy}-{sample_size}"
elapsed_time = np.round((time.time() - start_time) / 60, 2)
logger.info(f"finish experiment {experiment} in {elapsed_time}min")
# sample bootstrap from batch logged bandit feedback
boot_bandit_feedback = obd.sample_bootstrap_bandit_feedback(
test_size=test_size, is_timeseries_split=True, random_state=b)
# train an evaluation on the training set of the logged bandit feedback data
action_dist = evaluation_policy.fit(
context=boot_bandit_feedback["context"],
action=boot_bandit_feedback["action"],
reward=boot_bandit_feedback["reward"],
pscore=boot_bandit_feedback["pscore"],
position=boot_bandit_feedback["position"],
)
# make action selections (predictions)
action_dist = evaluation_policy.predict(
context=boot_bandit_feedback["context_test"])
# estimate the policy value of a given counterfactual algorithm by the three OPE estimators.
ipw = InverseProbabilityWeighting()
ope_results[b] = (ipw.estimate_policy_value(
reward=boot_bandit_feedback["reward_test"],
action=boot_bandit_feedback["action_test"],
position=boot_bandit_feedback["position_test"],
pscore=boot_bandit_feedback["pscore_test"],
action_dist=action_dist,
) / ground_truth)
print(
f"{b+1}th iteration: {np.round((time.time() - start) / 60, 2)}min")
ope_results_dict = estimate_confidence_interval_by_bootstrap(
samples=ope_results, random_state=random_state)
ope_results_dict["mean(no-boot)"] = ope_results.mean()
ope_results_dict["std"] = np.std(ope_results, ddof=1)
ope_results_df = pd.DataFrame(ope_results_dict, index=["ipw"])
