Merge pull request #669 from skzhang1/cv_strategy

Support customized cross-validation strategy
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zsk 2022-08-24 09:12:04 -04:00 committed by GitHub
commit da2ae83765
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2 changed files with 72 additions and 24 deletions

View File

@ -366,6 +366,7 @@ class AutoMLState:
state.best_loss,
state.n_jobs,
state.learner_classes.get(estimator),
state.cv_score_agg_func,
state.log_training_metric,
this_estimator_kwargs,
)
@ -734,6 +735,7 @@ class AutoML(BaseEstimator):
settings["min_sample_size"] = settings.get("min_sample_size", MIN_SAMPLE_TRAIN)
settings["use_ray"] = settings.get("use_ray", False)
settings["metric_constraints"] = settings.get("metric_constraints", [])
settings["cv_score_agg_func"] = settings.get("cv_score_agg_func", None)
settings["fit_kwargs_by_estimator"] = settings.get(
"fit_kwargs_by_estimator", {}
)
@ -2144,6 +2146,7 @@ class AutoML(BaseEstimator):
use_ray=None,
metric_constraints=None,
custom_hp=None,
cv_score_agg_func=None,
skip_transform=None,
fit_kwargs_by_estimator=None,
**fit_kwargs,
@ -2366,6 +2369,38 @@ class AutoML(BaseEstimator):
}
```
cv_score_agg_func: customized cross-validation scores aggregate function. Default to average metrics across folds. If specificed, this function needs to
have the following signature:
```python
def cv_score_agg_func(val_loss_folds, log_metrics_folds):
return metric_to_minimize, metrics_to_log
```
val_loss_folds - list of floats, the loss scores of each fold; log_metrics_folds - list of dicts/floats, the metrics of each fold to log.
This function should return the final aggregate result of all folds. A float number of the minimization objective, and a dictionary as the metrics to log or None.
E.g.,
```python
def cv_score_agg_func(val_loss_folds, log_metrics_folds):
metric_to_minimize = sum(val_loss_folds)/len(val_loss_folds)
metrics_to_log = None
for single_fold in log_metrics_folds:
if metrics_to_log is None:
metrics_to_log = single_fold
elif isinstance(metrics_to_log, dict):
metrics_to_log = {k: metrics_to_log[k] + v for k, v in single_fold.items()}
else:
metrics_to_log += single_fold
if metrics_to_log:
n = len(val_loss_folds)
metrics_to_log = {k: v / n for k, v in metrics_to_log.items()} if isinstance(metrics_to_log, dict) else metrics_to_log / n
return metric_to_minimize, metrics_to_log
```
fit_kwargs_by_estimator: dict, default=None | The user specified keywords arguments, grouped by estimator name.
For TransformersEstimator, available fit_kwargs can be found from
[TrainingArgumentsForAuto](nlp/huggingface/training_args).
e.g.,
skip_transform: boolean, default=False | Whether to pre-process data prior to modeling.
fit_kwargs_by_estimator: dict, default=None | The user specified keywords arguments, grouped by estimator name.
For TransformersEstimator, available fit_kwargs can be found from
@ -2568,6 +2603,9 @@ class AutoML(BaseEstimator):
eval_method = self._decide_eval_method(eval_method, time_budget)
self._state.eval_method = eval_method
logger.info("Evaluation method: {}".format(eval_method))
self._state.cv_score_agg_func = cv_score_agg_func or self._settings.get(
"cv_score_agg_func"
)
self._retrain_in_budget = retrain_full == "budget" and (
eval_method == "holdout" and self._state.X_val is None

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@ -431,6 +431,26 @@ def get_val_loss(
return val_loss, metric_for_logging, train_time, pred_time
def default_cv_score_agg_func(val_loss_folds, log_metrics_folds):
metric_to_minimize = sum(val_loss_folds) / len(val_loss_folds)
metrics_to_log = None
for single_fold in log_metrics_folds:
if metrics_to_log is None:
metrics_to_log = single_fold
elif isinstance(metrics_to_log, dict):
metrics_to_log = {k: metrics_to_log[k] + v for k, v in single_fold.items()}
else:
metrics_to_log += single_fold
if metrics_to_log:
n = len(val_loss_folds)
metrics_to_log = (
{k: v / n for k, v in metrics_to_log.items()}
if isinstance(metrics_to_log, dict)
else metrics_to_log / n
)
return metric_to_minimize, metrics_to_log
def evaluate_model_CV(
config,
estimator,
@ -441,15 +461,18 @@ def evaluate_model_CV(
task,
eval_metric,
best_val_loss,
cv_score_agg_func=None,
log_training_metric=False,
fit_kwargs={},
):
if cv_score_agg_func is None:
cv_score_agg_func = default_cv_score_agg_func
start_time = time.time()
total_val_loss = 0
total_metric = None
val_loss_folds = []
log_metric_folds = []
metric = None
train_time = pred_time = 0
valid_fold_num = total_fold_num = 0
total_fold_num = 0
n = kf.get_n_splits()
X_train_split, y_train_split = X_train_all, y_train_all
if task in CLASSIFICATION:
@ -471,7 +494,6 @@ def evaluate_model_CV(
else:
kf = kf.split(X_train_split)
rng = np.random.RandomState(2020)
val_loss_list = []
budget_per_train = budget / n
if "sample_weight" in fit_kwargs:
weight = fit_kwargs["sample_weight"]
@ -514,33 +536,19 @@ def evaluate_model_CV(
log_training_metric=log_training_metric,
fit_kwargs=fit_kwargs,
)
if isinstance(metric_i, dict) and "intermediate_results" in metric_i.keys():
del metric_i["intermediate_results"]
if weight is not None:
fit_kwargs["sample_weight"] = weight
valid_fold_num += 1
total_fold_num += 1
total_val_loss += val_loss_i
if log_training_metric or not isinstance(eval_metric, str):
if isinstance(total_metric, dict):
total_metric = {k: total_metric[k] + v for k, v in metric_i.items()}
elif total_metric is not None:
total_metric += metric_i
else:
total_metric = metric_i
val_loss_folds.append(val_loss_i)
log_metric_folds.append(metric_i)
train_time += train_time_i
pred_time += pred_time_i
if valid_fold_num == n:
val_loss_list.append(total_val_loss / valid_fold_num)
total_val_loss = valid_fold_num = 0
elif time.time() - start_time >= budget:
val_loss_list.append(total_val_loss / valid_fold_num)
if time.time() - start_time >= budget:
break
val_loss = np.max(val_loss_list)
val_loss, metric = cv_score_agg_func(val_loss_folds, log_metric_folds)
n = total_fold_num
if log_training_metric or not isinstance(eval_metric, str):
if isinstance(total_metric, dict):
metric = {k: v / n for k, v in total_metric.items()}
else:
metric = total_metric / n
pred_time /= n
return val_loss, metric, train_time, pred_time
@ -562,6 +570,7 @@ def compute_estimator(
best_val_loss=np.Inf,
n_jobs=1,
estimator_class=None,
cv_score_agg_func=None,
log_training_metric=False,
fit_kwargs={},
):
@ -608,6 +617,7 @@ def compute_estimator(
task,
eval_metric,
best_val_loss,
cv_score_agg_func,
log_training_metric=log_training_metric,
fit_kwargs=fit_kwargs,
)