def load_model(model: Union[tf.keras.Model, torch.nn.Module],
weights_path: str,
load_optimizer: bool = False):
"""Load saved weights for a given model.
This method can be used with TensorFlow models:
```python
m = fe.build(fe.architecture.tensorflow.LeNet, optimizer_fn="adam")
fe.backend.save_model(m, save_dir="tmp", model_name="test")
fe.backend.load_model(m, weights_path="tmp/test.h5")
```
This method can be used with PyTorch models:
```python
m = fe.build(fe.architecture.pytorch.LeNet, optimizer_fn="adam")
fe.backend.save_model(m, save_dir="tmp", model_name="test")
fe.backend.load_model(m, weights_path="tmp/test.pt")
```
Args:
model: A neural network instance to load.
weights_path: Path to the `model` weights.
load_optimizer: Whether to load optimizer. If True, then it will load <weights_opt> file in the path.
Raises:
ValueError: If `model` is an unacceptable data type.
"""
assert hasattr(
model,
"fe_compiled") and model.fe_compiled, "model must be built by fe.build"
if isinstance(model, tf.keras.Model):
model.load_weights(weights_path)
if load_optimizer:
assert model.current_optimizer, "optimizer does not exist"
optimizer_path = "{}_opt.pkl".format(
os.path.splitext(weights_path)[0])
assert os.path.exists(
optimizer_path), "cannot find optimizer path: {}".format(
optimizer_path)
with open(optimizer_path, 'rb') as f:
state_dict = pickle.load(f)
model.current_optimizer.set_weights(state_dict['weights'])
set_lr(model, state_dict['lr'])
elif isinstance(model, torch.nn.Module):
model.load_state_dict(torch.load(weights_path))
if load_optimizer:
assert model.current_optimizer, "optimizer does not exist"
optimizer_path = "{}_opt.pt".format(
os.path.splitext(weights_path)[0])
assert os.path.exists(
optimizer_path), "cannot find optimizer path: {}".format(
optimizer_path)
model.current_optimizer.load_state_dict(torch.load(optimizer_path))
else:
raise ValueError("Unrecognized model instance {}".format(type(model)))
def on_epoch_end(self, data: Data) -> None:
if self.monitor_op(data[self.inputs[0]], self.best):
self.best = data[self.inputs[0]]
self.wait = 0
else:
self.wait += 1
if self.wait >= self.patience:
new_lr = max(self.min_lr, np.float32(self.factor * get_lr(self.model)))
set_lr(self.model, new_lr)
self.wait = 0
data.write_with_log(self.outputs[0], new_lr)
print("FastEstimator-ReduceLROnPlateau: learning rate reduced to {}".format(new_lr))
def on_epoch_begin(self, data: Data) -> None:
if self.system.mode == "train" and self.schedule_mode == "epoch":
if isinstance(self.lr_fn, ARC):
if self.system.epoch_idx > 1 and (self.system.epoch_idx % self.lr_fn.frequency == 1
or self.lr_fn.frequency == 1):
multiplier = self.lr_fn.predict_next_multiplier()
new_lr = np.float32(get_lr(model=self.model) * multiplier)
set_lr(self.model, new_lr)
print("FastEstimator-ARC: Multiplying LR by {}".format(multiplier))
else:
new_lr = np.float32(self.lr_fn(self.system.epoch_idx))
set_lr(self.model, new_lr)
def on_batch_begin(self, data: Data) -> None:
if self.system.mode == "train" and self.schedule_mode == "step":
new_lr = np.float32(self.lr_fn(self.system.global_step))
set_lr(self.model, new_lr)
def on_epoch_begin(self, data: Data) -> None:
if self.schedule_mode == "epoch":
new_lr = np.float32(self.lr_fn(self.system.epoch_idx))
set_lr(self.model, new_lr)