autogen/flaml/ml.py

295 lines
12 KiB
Python

'''!
* Copyright (c) 2020-2021 Microsoft Corporation. All rights reserved.
* Licensed under the MIT License.
'''
import time
import numpy as np
import pandas as pd
from sklearn.metrics import mean_squared_error, r2_score, roc_auc_score, \
accuracy_score, mean_absolute_error, log_loss, average_precision_score, \
f1_score
from sklearn.model_selection import RepeatedStratifiedKFold
from .model import (
XGBoostEstimator, XGBoostSklearnEstimator, RandomForestEstimator,
LGBMEstimator, LRL1Classifier, LRL2Classifier, CatBoostEstimator,
ExtraTreeEstimator, KNeighborsEstimator)
import logging
logger = logging.getLogger(__name__)
def get_estimator_class(task, estimator_name):
''' when adding a new learner, need to add an elif branch '''
if 'xgboost' in estimator_name:
if 'regression' in task:
estimator_class = XGBoostEstimator
else:
estimator_class = XGBoostSklearnEstimator
elif 'rf' in estimator_name:
estimator_class = RandomForestEstimator
elif 'lgbm' in estimator_name:
estimator_class = LGBMEstimator
elif 'lrl1' in estimator_name:
estimator_class = LRL1Classifier
elif 'lrl2' in estimator_name:
estimator_class = LRL2Classifier
elif 'catboost' in estimator_name:
estimator_class = CatBoostEstimator
elif 'extra_tree' in estimator_name:
estimator_class = ExtraTreeEstimator
elif 'kneighbor' in estimator_name:
estimator_class = KNeighborsEstimator
else:
raise ValueError(
estimator_name + ' is not a built-in learner. '
'Please use AutoML.add_learner() to add a customized learner.')
return estimator_class
def sklearn_metric_loss_score(
metric_name, y_predict, y_true, labels=None, sample_weight=None
):
'''Loss using the specified metric
Args:
metric_name: A string of the metric name, one of
'r2', 'rmse', 'mae', 'mse', 'accuracy', 'roc_auc', 'log_loss',
'f1', 'ap', 'micro_f1', 'macro_f1'
y_predict: A 1d or 2d numpy array of the predictions which can be
used to calculate the metric. E.g., 2d for log_loss and 1d
for others.
y_true: A 1d numpy array of the true labels
labels: A 1d numpy array of the unique labels
sample_weight: A 1d numpy array of the sample weight
Returns:
score: A float number of the loss, the lower the better
'''
metric_name = metric_name.lower()
if 'r2' in metric_name:
score = 1.0 - r2_score(y_true, y_predict, sample_weight=sample_weight)
elif metric_name == 'rmse':
score = np.sqrt(mean_squared_error(
y_true, y_predict, sample_weight=sample_weight))
elif metric_name == 'mae':
score = mean_absolute_error(
y_true, y_predict, sample_weight=sample_weight)
elif metric_name == 'mse':
score = mean_squared_error(
y_true, y_predict, sample_weight=sample_weight)
elif metric_name == 'accuracy':
score = 1.0 - accuracy_score(
y_true, y_predict, sample_weight=sample_weight)
elif 'roc_auc' in metric_name:
score = 1.0 - roc_auc_score(
y_true, y_predict, sample_weight=sample_weight)
elif 'log_loss' in metric_name:
score = log_loss(
y_true, y_predict, labels=labels, sample_weight=sample_weight)
elif 'micro_f1' in metric_name:
score = 1 - f1_score(y_true, y_predict, sample_weight=sample_weight, average='micro')
elif 'macro_f1' in metric_name:
score = 1 - f1_score(y_true, y_predict, sample_weight=sample_weight, average='macro')
elif 'f1' in metric_name:
score = 1 - f1_score(y_true, y_predict, sample_weight=sample_weight)
elif 'ap' in metric_name:
score = 1 - average_precision_score(
y_true, y_predict, sample_weight=sample_weight)
else:
raise ValueError(
metric_name + ' is not a built-in metric, '
'currently built-in metrics are: '
'r2, rmse, mae, mse, accuracy, roc_auc, log_loss, f1, ap. '
'please pass a customized metric function to AutoML.fit(metric=func)')
return score
def get_y_pred(estimator, X, eval_metric, obj):
if eval_metric in ['roc_auc', 'ap'] and 'binary' in obj:
y_pred_classes = estimator.predict_proba(X)
y_pred = y_pred_classes[
:, 1] if y_pred_classes.ndim > 1 else y_pred_classes
elif eval_metric in ['log_loss', 'roc_auc']:
y_pred = estimator.predict_proba(X)
else:
y_pred = estimator.predict(X)
return y_pred
def get_test_loss(
estimator, X_train, y_train, X_test, y_test, weight_test,
eval_metric, obj, labels=None, budget=None, train_loss=False, fit_kwargs={}
):
start = time.time()
train_time = estimator.fit(X_train, y_train, budget, **fit_kwargs)
if isinstance(eval_metric, str):
test_pred_y = get_y_pred(estimator, X_test, eval_metric, obj)
test_loss = sklearn_metric_loss_score(eval_metric, test_pred_y, y_test,
labels, weight_test)
if train_loss is not False:
test_pred_y = get_y_pred(estimator, X_train, eval_metric, obj)
train_loss = sklearn_metric_loss_score(
eval_metric, test_pred_y,
y_train, labels, fit_kwargs.get('sample_weight'))
else: # customized metric function
test_loss, train_loss = eval_metric(
X_test, y_test, estimator, labels, X_train, y_train,
weight_test, fit_kwargs.get('sample_weight'))
train_time = time.time() - start
return test_loss, train_time, train_loss
def train_model(estimator, X_train, y_train, budget, fit_kwargs={}):
train_time = estimator.fit(X_train, y_train, budget, **fit_kwargs)
return train_time
def evaluate_model(
estimator, X_train, y_train, X_val, y_val, weight_val,
budget, kf, task, eval_method, eval_metric, best_val_loss, train_loss=False,
fit_kwargs={}
):
if 'holdout' in eval_method:
val_loss, train_loss, train_time = evaluate_model_holdout(
estimator, X_train, y_train, X_val, y_val, weight_val, budget,
task, eval_metric, best_val_loss, train_loss=train_loss,
fit_kwargs=fit_kwargs)
else:
val_loss, train_loss, train_time = evaluate_model_CV(
estimator, X_train, y_train, budget, kf, task,
eval_metric, best_val_loss, train_loss=train_loss,
fit_kwargs=fit_kwargs)
return val_loss, train_loss, train_time
def evaluate_model_holdout(
estimator, X_train, y_train, X_val, y_val,
weight_val, budget, task, eval_metric, best_val_loss, train_loss=False,
fit_kwargs={}
):
val_loss, train_time, train_loss = get_test_loss(
estimator, X_train, y_train, X_val, y_val, weight_val, eval_metric,
task, budget=budget, train_loss=train_loss, fit_kwargs=fit_kwargs)
return val_loss, train_loss, train_time
def evaluate_model_CV(
estimator, X_train_all, y_train_all, budget, kf,
task, eval_metric, best_val_loss, train_loss=False, fit_kwargs={}
):
start_time = time.time()
total_val_loss = total_train_loss = 0
train_time = 0
valid_fold_num = 0
n = kf.get_n_splits()
X_train_split, y_train_split = X_train_all, y_train_all
if task == 'regression':
labels = None
else:
labels = np.unique(y_train_all)
if isinstance(kf, RepeatedStratifiedKFold):
kf = kf.split(X_train_split, y_train_split)
else:
kf = kf.split(X_train_split)
rng = np.random.RandomState(2020)
val_loss_list = []
budget_per_train = budget / (n + 1)
if 'sample_weight' in fit_kwargs:
weight = fit_kwargs['sample_weight']
weight_val = None
else:
weight = weight_val = None
for train_index, val_index in kf:
train_index = rng.permutation(train_index)
if isinstance(X_train_all, pd.DataFrame):
X_train, X_val = X_train_split.iloc[
train_index], X_train_split.iloc[val_index]
else:
X_train, X_val = X_train_split[
train_index], X_train_split[val_index]
if isinstance(y_train_all, pd.Series):
y_train, y_val = y_train_split.iloc[
train_index], y_train_split.iloc[val_index]
else:
y_train, y_val = y_train_split[
train_index], y_train_split[val_index]
estimator.cleanup()
if weight is not None:
fit_kwargs['sample_weight'], weight_val = weight[
train_index], weight[val_index]
val_loss_i, train_time_i, train_loss_i = get_test_loss(
estimator, X_train, y_train, X_val, y_val, weight_val,
eval_metric, task, labels, budget_per_train,
train_loss=train_loss, fit_kwargs=fit_kwargs)
if weight is not None:
fit_kwargs['sample_weight'] = weight
valid_fold_num += 1
total_val_loss += val_loss_i
if train_loss is not False:
if total_train_loss != 0:
total_train_loss += train_loss_i
else:
total_train_loss = train_loss_i
train_time += train_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)
break
val_loss = np.max(val_loss_list)
if train_loss is not False:
train_loss = total_train_loss / n
budget -= time.time() - start_time
if val_loss < best_val_loss and budget > budget_per_train:
estimator.cleanup()
estimator.fit(X_train_all, y_train_all, budget, **fit_kwargs)
return val_loss, train_loss, train_time
def compute_estimator(
X_train, y_train, X_val, y_val, weight_val, budget, kf,
config_dic, task, estimator_name, eval_method, eval_metric,
best_val_loss=np.Inf, n_jobs=1, estimator_class=None, train_loss=False,
fit_kwargs={}
):
start_time = time.time()
estimator_class = estimator_class or get_estimator_class(
task, estimator_name)
estimator = estimator_class(
**config_dic, task=task, n_jobs=n_jobs)
val_loss, train_loss, train_time = evaluate_model(
estimator, X_train, y_train, X_val, y_val, weight_val, budget, kf, task,
eval_method, eval_metric, best_val_loss, train_loss=train_loss,
fit_kwargs=fit_kwargs)
all_time = time.time() - start_time
return estimator, val_loss, train_loss, train_time, all_time
def train_estimator(
X_train, y_train, config_dic, task,
estimator_name, n_jobs=1, estimator_class=None, budget=None, fit_kwargs={}
):
start_time = time.time()
estimator_class = estimator_class or get_estimator_class(
task, estimator_name)
estimator = estimator_class(**config_dic, task=task, n_jobs=n_jobs)
if X_train is not None:
train_time = train_model(
estimator, X_train, y_train, budget, fit_kwargs)
else:
estimator = estimator.estimator_class(**estimator.params)
train_time = time.time() - start_time
return estimator, train_time
def get_classification_objective(num_labels: int) -> str:
if num_labels == 2:
objective_name = 'binary:logistic'
else:
objective_name = 'multi:softmax'
return objective_name