class Predictor():
"""
slim class to make predictions on trained model
Args:
model - your model (nn.Module)
device - the device to send the inputs to
callbacks - (optional) list of lpd.callbacks to apply during the predictions phases and states
callbacks will be executed by the order of the list
name - a friendly identifier
Methods:
from_trainer - for creating a new Predictor instance from given Trainer
from_checkpoint - for creating a new Predictor instance from a saved Trainer checkpoint
predict_sample - make prediction on single sample
predict_batch - make prediction on single batch
predict_data_loader - make prediction on data loader (DataLoader/Iterable/Generator)
"""
def __init__(self, model, device, callbacks=None, name='lpd predictor'):
self._inner = Trainer(model=model,
device=device,
loss_func=None,
optimizer=None,
scheduler=None,
metrics=None,
train_data_loader=None,
val_data_loader=None,
train_steps=0,
val_steps=0,
callbacks=callbacks,
name=name)
@staticmethod
def from_trainer(trainer):
print(f'[Predictor] - Loading from trainer {trainer.name}')
predictor = Predictor(model=trainer.model,
device=trainer.device,
callbacks=trainer.callbacks,
name=f'Predictor-for-Trainer-{trainer.name}')
return predictor
@staticmethod
def from_checkpoint(dir_path, file_name, model, device):
full_path = dir_path + file_name
checkpoint = T.load(full_path, map_location=device)
print(f'[Predictor] - Loading from {full_path}')
model.load_state_dict(checkpoint['model'])
callbacks = None
if 'callbacks' in checkpoint:
callbacks = checkpoint['callbacks']
name = None
if 'name' in checkpoint:
name = checkpoint['name']
predictor = Predictor(model=model,
device=device,
callbacks=callbacks,
name=name)
return predictor
def predict_sample(self, inputs):
return self._inner.predict_sample(inputs)
def predict_batch(self, inputs):
return self._inner.predict_batch(inputs)
def predict_data_loader(self, inputs_data_loader, steps):
return self._inner.predict_data_loader(inputs_data_loader, steps)
def test_save_and_predict(self):
save_to_dir = os.path.dirname(__file__) + '/trainer_checkpoint/'
checkpoint_file_name = 'checkpoint'
trainer_file_name = 'trainer'
device = tu.get_gpu_device_if_available()
model = TestModel().to(device)
loss_func = nn.BCEWithLogitsLoss().to(device)
optimizer = optim.Adam(model.parameters(), lr=1e-4)
scheduler = None
metrics = BinaryAccuracyWithLogits(name='acc')
callbacks = [
LossOptimizerHandler(),
ModelCheckPoint(checkpoint_dir=save_to_dir,
checkpoint_file_name=checkpoint_file_name,
callback_monitor=CallbackMonitor(
monitor_type=MonitorType.LOSS,
stats_type=StatsType.VAL,
monitor_mode=MonitorMode.MIN),
save_best_only=True,
save_full_trainer=False),
]
data_loader = data_generator()
data_loader_steps = 100
num_epochs = 5
trainer = Trainer(model=model,
device=device,
loss_func=loss_func,
optimizer=optimizer,
scheduler=scheduler,
metrics=metrics,
train_data_loader=data_loader,
val_data_loader=data_loader,
train_steps=data_loader_steps,
val_steps=data_loader_steps,
callbacks=callbacks,
name='Predictor-Trainer-Test')
x1_x2, y = next(data_loader)
_ = trainer.predict_batch(x1_x2) # JUST TO CHECK THAT IT FUNCTIONS
sample = [x1_x2[0][0], x1_x2[1][0]]
# PREDICT BEFORE TRAIN
sample_prediction_before_train = trainer.predict_sample(sample)
trainer.train(num_epochs, verbose=0)
# PREDICT AFTER TRAIN
sample_prediction_from_trainer = trainer.predict_sample(sample)
# SAVE THE TRAINER
trainer.save_trainer(save_to_dir, trainer_file_name)
#-----------------------------------------------#
# CREATE PREDICTOR FROM CURRENT TRAINER
#-----------------------------------------------#
predictor_from_trainer = Predictor.from_trainer(trainer)
# PREDICT FROM PREDICTOR
sample_prediction_from_predictor = predictor_from_trainer.predict_sample(
sample)
self.assertFalse(
(sample_prediction_before_train == sample_prediction_from_trainer
).all())
self.assertTrue(
(sample_prediction_from_predictor == sample_prediction_from_trainer
).all())
#-----------------------------------------------#
# LOAD MODEL CHECKPOINT AS NEW PREDICTOR
#-----------------------------------------------#
fresh_device = tu.get_gpu_device_if_available()
fresh_model = TestModel().to(fresh_device)
loaded_predictor = Predictor.from_checkpoint(
save_to_dir, checkpoint_file_name + '_best_only', fresh_model,
fresh_device)
# PREDICT AFTER LOAD
sample_prediction_from_loaded_predictor = loaded_predictor.predict_sample(
sample)
self.assertFalse(
(sample_prediction_before_train == sample_prediction_from_trainer
).all())
self.assertTrue((sample_prediction_from_loaded_predictor ==
sample_prediction_from_trainer).all())
#-----------------------------------------------#
# LOAD TRAINER CHECKPOINT AS NEW PREDICTOR
#-----------------------------------------------#
fresh_device = tu.get_gpu_device_if_available()
fresh_model = TestModel().to(fresh_device)
loaded_predictor = Predictor.from_checkpoint(save_to_dir,
trainer_file_name,
fresh_model, fresh_device)
# PREDICT AFTER LOAD
sample_prediction_from_loaded_predictor = loaded_predictor.predict_sample(
sample)
self.assertFalse(
(sample_prediction_before_train == sample_prediction_from_trainer
).all())
self.assertTrue((sample_prediction_from_loaded_predictor ==
sample_prediction_from_trainer).all())
