def predict_generator(model,
generator,
steps=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
verbose=0):
"""See docstring for `Model.predict_generator`."""
if not context.executing_eagerly():
model._make_test_function()
steps_done = 0
wait_time = 0.01
all_outs = []
is_sequence = isinstance(generator, Sequence)
if not is_sequence and use_multiprocessing and workers > 1:
logging.warning(
UserWarning('Using a generator with `use_multiprocessing=True`'
' and multiple workers may duplicate your data.'
' Please consider using the`keras.utils.Sequence'
' class.'))
if steps is None:
if is_sequence:
steps = len(generator)
else:
raise ValueError('`steps=None` is only valid for a generator'
' based on the `keras.utils.Sequence` class.'
' Please specify `steps` or use the'
' `keras.utils.Sequence` class.')
enqueuer = None
try:
if workers > 0:
if is_sequence:
enqueuer = OrderedEnqueuer(
generator, use_multiprocessing=use_multiprocessing)
else:
enqueuer = GeneratorEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
wait_time=wait_time)
enqueuer.start(workers=workers, max_queue_size=max_queue_size)
output_generator = enqueuer.get()
else:
if is_sequence:
output_generator = iter(generator)
else:
output_generator = generator
if verbose == 1:
progbar = Progbar(target=steps)
while steps_done < steps:
generator_output = next(output_generator)
if isinstance(generator_output, tuple):
# Compatibility with the generators
# used for training.
if len(generator_output) == 2:
x, _ = generator_output
elif len(generator_output) == 3:
x, _, _ = generator_output
else:
raise ValueError('Output of generator should be '
'a tuple `(x, y, sample_weight)` '
'or `(x, y)`. Found: ' + str(generator_output))
else:
# Assumes a generator that only
# yields inputs (not targets and sample weights).
x = generator_output
outs = model.predict_on_batch(x)
if not isinstance(outs, list):
outs = [outs]
if not all_outs:
for out in outs:
all_outs.append([])
for i, out in enumerate(outs):
all_outs[i].append(out)
steps_done += 1
if verbose == 1:
progbar.update(steps_done)
finally:
if enqueuer is not None:
enqueuer.stop()
if len(all_outs) == 1:
if steps_done == 1:
return all_outs[0][0]
else:
return np.concatenate(all_outs[0])
if steps_done == 1:
return [out[0] for out in all_outs]
else:
return [np.concatenate(out) for out in all_outs]
def evaluate_generator(model,
generator,
steps=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
verbose=0):
"""See docstring for `Model.evaluate_generator`."""
if not context.executing_eagerly():
model._make_test_function()
if hasattr(model, 'metrics'):
for m in model.stateful_metric_functions:
m.reset_states()
stateful_metric_indices = [
i for i, name in enumerate(model.metrics_names)
if str(name) in model.stateful_metric_names]
else:
stateful_metric_indices = []
steps_done = 0
wait_time = 0.01
all_outs = []
batch_sizes = []
is_sequence = isinstance(generator, Sequence)
if not is_sequence and use_multiprocessing and workers > 1:
logging.warning(
UserWarning('Using a generator with `use_multiprocessing=True`'
' and multiple workers may duplicate your data.'
' Please consider using the`keras.utils.Sequence'
' class.'))
if steps is None:
if is_sequence:
steps = len(generator)
else:
raise ValueError('`steps=None` is only valid for a generator'
' based on the `keras.utils.Sequence` class.'
' Please specify `steps` or use the'
' `keras.utils.Sequence` class.')
enqueuer = None
try:
if workers > 0:
if is_sequence:
enqueuer = OrderedEnqueuer(
generator, use_multiprocessing=use_multiprocessing)
else:
enqueuer = GeneratorEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
wait_time=wait_time)
enqueuer.start(workers=workers, max_queue_size=max_queue_size)
output_generator = enqueuer.get()
else:
if is_sequence:
output_generator = iter(generator)
else:
output_generator = generator
if verbose == 1:
progbar = Progbar(target=steps)
while steps_done < steps:
generator_output = next(output_generator)
if not hasattr(generator_output, '__len__'):
raise ValueError('Output of generator should be a tuple '
'(x, y, sample_weight) '
'or (x, y). Found: ' + str(generator_output))
if len(generator_output) == 2:
x, y = generator_output
sample_weight = None
elif len(generator_output) == 3:
x, y, sample_weight = generator_output
else:
raise ValueError('Output of generator should be a tuple '
'(x, y, sample_weight) '
'or (x, y). Found: ' + str(generator_output))
outs = model.test_on_batch(x, y, sample_weight=sample_weight)
if isinstance(x, list):
batch_size = x[0].shape[0]
elif isinstance(x, dict):
batch_size = list(x.values())[0].shape[0]
else:
batch_size = x.shape[0]
if batch_size == 0:
raise ValueError('Received an empty batch. '
'Batches should at least contain one item.')
all_outs.append(outs)
steps_done += 1
batch_sizes.append(batch_size)
if verbose == 1:
progbar.update(steps_done)
finally:
if enqueuer is not None:
enqueuer.stop()
if not isinstance(outs, list):
return np.average(np.asarray(all_outs), weights=batch_sizes)
else:
averages = []
for i in range(len(outs)):
if i not in stateful_metric_indices:
averages.append(
np.average([out[i] for out in all_outs], weights=batch_sizes))
else:
averages.append(np.float64(all_outs[-1][i]))
return averages
def fit_generator(model,
generator,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=True,
initial_epoch=0):
"""See docstring for `Model.fit_generator`."""
wait_time = 0.01 # in seconds
epoch = initial_epoch
do_validation = bool(validation_data)
if not context.executing_eagerly():
model._make_train_function()
if do_validation:
model._make_test_function()
is_sequence = isinstance(generator, Sequence)
if not is_sequence and use_multiprocessing and workers > 1:
logging.warning(
UserWarning('Using a generator with `use_multiprocessing=True`'
' and multiple workers may duplicate your data.'
' Please consider using the`keras.utils.Sequence'
' class.'))
if steps_per_epoch is None:
if is_sequence:
steps_per_epoch = len(generator)
else:
raise ValueError('`steps_per_epoch=None` is only valid for a'
' generator based on the `keras.utils.Sequence`'
' class. Please specify `steps_per_epoch` or use'
' the `keras.utils.Sequence` class.')
# python 2 has 'next', 3 has '__next__'
# avoid any explicit version checks
val_gen = (
hasattr(validation_data, 'next') or
hasattr(validation_data, '__next__') or
isinstance(validation_data, Sequence))
if (val_gen and not isinstance(validation_data, Sequence) and
not validation_steps):
raise ValueError('`validation_steps=None` is only valid for a'
' generator based on the `keras.utils.Sequence`'
' class. Please specify `validation_steps` or use'
' the `keras.utils.Sequence` class.')
enqueuer = None
val_enqueuer = None
try:
val_x, val_y, val_sample_weights = validation_data, None, None
if do_validation and not val_gen:
# Prepare data for validation
if len(validation_data) == 2:
val_x, val_y = validation_data # pylint: disable=unpacking-non-sequence
val_sample_weights = None
elif len(validation_data) == 3:
val_x, val_y, val_sample_weights = validation_data # pylint: disable=unpacking-non-sequence
else:
raise ValueError(
'`validation_data` should be a tuple '
'`(val_x, val_y, val_sample_weight)` '
'or `(val_x, val_y)`. Found: ' + str(validation_data))
val_x, val_y, val_sample_weights = model._standardize_user_data(
val_x, val_y, val_sample_weights)
callbacks = cbks.configure_callbacks(
callbacks,
model,
do_validation=do_validation,
val_inputs=val_x,
val_targets=val_y,
val_sample_weights=val_sample_weights,
epochs=epochs,
validation_steps=validation_steps,
steps_per_epoch=steps_per_epoch,
verbose=verbose)
if workers > 0:
if is_sequence:
enqueuer = OrderedEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
shuffle=shuffle)
else:
enqueuer = GeneratorEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
wait_time=wait_time)
enqueuer.start(workers=workers, max_queue_size=max_queue_size)
output_generator = enqueuer.get()
else:
if is_sequence:
output_generator = iter(generator)
else:
output_generator = generator
callbacks.on_train_begin()
# Construct epoch logs.
epoch_logs = {}
while epoch < epochs:
for m in model.stateful_metric_functions:
m.reset_states()
callbacks.on_epoch_begin(epoch)
steps_done = 0
batch_index = 0
while steps_done < steps_per_epoch:
generator_output = next(output_generator)
if not hasattr(generator_output, '__len__'):
raise ValueError('Output of generator should be '
'a tuple `(x, y, sample_weight)` '
'or `(x, y)`. Found: ' + str(generator_output))
if len(generator_output) == 2:
x, y = generator_output
sample_weight = None
elif len(generator_output) == 3:
x, y, sample_weight = generator_output
else:
raise ValueError('Output of generator should be '
'a tuple `(x, y, sample_weight)` '
'or `(x, y)`. Found: ' + str(generator_output))
# build batch logs
batch_logs = {}
if isinstance(x, list):
batch_size = x[0].shape[0]
elif isinstance(x, dict):
batch_size = list(x.values())[0].shape[0]
else:
batch_size = x.shape[0]
batch_logs['batch'] = batch_index
batch_logs['size'] = batch_size
callbacks.on_batch_begin(batch_index, batch_logs)
outs = model.train_on_batch(
x, y, sample_weight=sample_weight, class_weight=class_weight)
if not isinstance(outs, list):
outs = [outs]
for l, o in zip(model.metrics_names, outs):
batch_logs[l] = o
callbacks.on_batch_end(batch_index, batch_logs)
batch_index += 1
steps_done += 1
# Epoch finished.
if steps_done >= steps_per_epoch and do_validation:
if val_gen:
val_outs = evaluate_generator(
model,
validation_data,
validation_steps,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size)
else:
# No need for try/except because
# data has already been validated.
val_outs = model.evaluate(
val_x,
val_y,
batch_size=batch_size,
sample_weight=val_sample_weights,
verbose=0)
if not isinstance(val_outs, list):
val_outs = [val_outs]
# Same labels assumed.
for l, o in zip(model.metrics_names, val_outs):
epoch_logs['val_' + l] = o
if callbacks.model.stop_training:
break
callbacks.on_epoch_end(epoch, epoch_logs)
epoch += 1
if callbacks.model.stop_training:
break
finally:
try:
if enqueuer is not None:
enqueuer.stop()
finally:
if val_enqueuer is not None:
val_enqueuer.stop()
callbacks.on_train_end()
return model.history
def fit_generator(model,
generator,
steps_per_epoch=None,
epochs=1,
verbose=1,
callbacks=None,
validation_data=None,
validation_steps=None,
class_weight=None,
max_queue_size=10,
workers=1,
use_multiprocessing=False,
shuffle=True,
initial_epoch=0):
"""See docstring for `Model.fit_generator`."""
wait_time = 0.01 # in seconds
epoch = initial_epoch
do_validation = bool(validation_data)
is_sequence = isinstance(generator, Sequence)
if not is_sequence and use_multiprocessing and workers > 1:
logging.warning(
UserWarning('Using a generator with `use_multiprocessing=True`'
' and multiple workers may duplicate your data.'
' Please consider using the`keras.utils.Sequence'
' class.'))
if steps_per_epoch is None:
if is_sequence:
steps_per_epoch = len(generator)
else:
raise ValueError('`steps_per_epoch=None` is only valid for a'
' generator based on the `keras.utils.Sequence`'
' class. Please specify `steps_per_epoch` or use'
' the `keras.utils.Sequence` class.')
# python 2 has 'next', 3 has '__next__'
# avoid any explicit version checks
val_gen = (
hasattr(validation_data, 'next') or
hasattr(validation_data, '__next__') or
isinstance(validation_data, Sequence))
if (val_gen and not isinstance(validation_data, Sequence) and
not validation_steps):
raise ValueError('`validation_steps=None` is only valid for a'
' generator based on the `keras.utils.Sequence`'
' class. Please specify `validation_steps` or use'
' the `keras.utils.Sequence` class.')
# Prepare display labels.
out_labels = model.metrics_names
callback_metrics = out_labels + ['val_%s' % n for n in out_labels]
# prepare callbacks
model.history = cbks.History()
callbacks = [cbks.BaseLogger()] + (callbacks or []) + [model.history]
if verbose:
callbacks += [cbks.ProgbarLogger(count_mode='steps')]
callbacks = cbks.CallbackList(callbacks)
# it's possible to callback a different model than self:
if hasattr(model, 'callback_model') and model.callback_model:
callback_model = model.callback_model
else:
callback_model = model
callbacks.set_model(callback_model)
callback_params = {
'epochs': epochs,
'steps': steps_per_epoch,
'verbose': verbose,
'do_validation': do_validation,
'metrics': callback_metrics,
}
if do_validation:
# need to create the test_function before start of the first epoch
# because TensorBoard callback on_epoch_begin adds summary to the
# list of fetches of the test_function
model._make_test_function()
# determine the number of validation batches given a generator
if validation_steps:
callback_params.update({'validation_steps': validation_steps})
elif isinstance(validation_data, Sequence):
callback_params.update({'validation_steps': len(validation_data)})
callbacks.set_params(callback_params)
enqueuer = None
val_enqueuer = None
try:
if do_validation and not val_gen:
# Prepare data for validation
if len(validation_data) == 2:
val_x, val_y = validation_data # pylint: disable=unpacking-non-sequence
val_sample_weight = None
elif len(validation_data) == 3:
val_x, val_y, val_sample_weight = validation_data # pylint: disable=unpacking-non-sequence
else:
raise ValueError(
'`validation_data` should be a tuple '
'`(val_x, val_y, val_sample_weight)` '
'or `(val_x, val_y)`. Found: ' + str(validation_data))
val_x, val_y, val_sample_weights = model._standardize_user_data(
val_x, val_y, val_sample_weight)
val_data = val_x + val_y + val_sample_weights
if model.uses_learning_phase and not isinstance(K.learning_phase(), int):
val_data += [0.]
for cbk in callbacks:
cbk.validation_data = val_data
if workers > 0:
if is_sequence:
enqueuer = OrderedEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
shuffle=shuffle)
else:
enqueuer = GeneratorEnqueuer(
generator,
use_multiprocessing=use_multiprocessing,
wait_time=wait_time)
enqueuer.start(workers=workers, max_queue_size=max_queue_size)
output_generator = enqueuer.get()
else:
if is_sequence:
output_generator = iter(generator)
else:
output_generator = generator
callback_model.stop_training = False
# validation_data must be set before on_train_begin() is called
# so that TensorboardCallback can validate its input
callbacks.on_train_begin()
# Construct epoch logs.
epoch_logs = {}
while epoch < epochs:
for m in model.stateful_metric_functions:
m.reset_states()
callbacks.on_epoch_begin(epoch)
steps_done = 0
batch_index = 0
while steps_done < steps_per_epoch:
generator_output = next(output_generator)
if not hasattr(generator_output, '__len__'):
raise ValueError('Output of generator should be '
'a tuple `(x, y, sample_weight)` '
'or `(x, y)`. Found: ' + str(generator_output))
if len(generator_output) == 2:
x, y = generator_output
sample_weight = None
elif len(generator_output) == 3:
x, y, sample_weight = generator_output
else:
raise ValueError('Output of generator should be '
'a tuple `(x, y, sample_weight)` '
'or `(x, y)`. Found: ' + str(generator_output))
# build batch logs
batch_logs = {}
if isinstance(x, list):
batch_size = x[0].shape[0]
elif isinstance(x, dict):
batch_size = list(x.values())[0].shape[0]
else:
batch_size = x.shape[0]
batch_logs['batch'] = batch_index
batch_logs['size'] = batch_size
callbacks.on_batch_begin(batch_index, batch_logs)
outs = model.train_on_batch(
x, y, sample_weight=sample_weight, class_weight=class_weight)
if not isinstance(outs, list):
outs = [outs]
for l, o in zip(out_labels, outs):
batch_logs[l] = o
callbacks.on_batch_end(batch_index, batch_logs)
batch_index += 1
steps_done += 1
# Epoch finished.
if steps_done >= steps_per_epoch and do_validation:
if val_gen:
val_outs = evaluate_generator(
model,
validation_data,
validation_steps,
workers=workers,
use_multiprocessing=use_multiprocessing,
max_queue_size=max_queue_size)
else:
# No need for try/except because
# data has already been validated.
val_outs = model.evaluate(
val_x,
val_y,
batch_size=batch_size,
sample_weight=val_sample_weights,
verbose=0)
if not isinstance(val_outs, list):
val_outs = [val_outs]
# Same labels assumed.
for l, o in zip(out_labels, val_outs):
epoch_logs['val_' + l] = o
if callback_model.stop_training:
break
callbacks.on_epoch_end(epoch, epoch_logs)
epoch += 1
if callback_model.stop_training:
break
finally:
try:
if enqueuer is not None:
enqueuer.stop()
finally:
if val_enqueuer is not None:
val_enqueuer.stop()
callbacks.on_train_end()
return model.history