Model

class poutyne.Model(network, optimizer, loss_function, *, batch_metrics=None, epoch_metrics=None, device=None)[source]

The Model class encapsulates a PyTorch network, a PyTorch optimizer, a loss function and metric functions. It allows the user to train a neural network without hand-coding the epoch/step logic.

Parameters
  • network (torch.nn.Module) – A PyTorch network.

  • optimizer (Union[torch.optim.Optimizer, str, dict]) – If torch.optim.Optimier, an initialized PyTorch. If str, should be the name of the optimizer in Pytorch (i.e. ‘Adam’ for torch.optim.Adam). If dict, should contain a key 'optim' with the value be the name of the optimizer; other entries are passed to the optimizer as keyword arguments. (Default value = None)

  • loss_function (Union[Callable, str]) – can also be a string with the same name as a PyTorch loss function (either the functional or object name). The loss function must have the signature loss_function(input, target) where input is the prediction of the network and target is the ground truth. (Default value = None)

  • batch_metrics (list) – List of functions with the same signature as the loss function. Each metric can be any PyTorch loss function. It can also be a string with the same name as a PyTorch loss function (either the functional or object name). ‘accuracy’ (or just ‘acc’) is also a valid metric. Each metric function is called on each batch of the optimization and on the validation batches at the end of the epoch. (Default value = None)

  • epoch_metrics (list) – List of functions with the same signature as EpochMetric (Default value = None)

  • device (Union[torch.torch.device, List[torch.torch.device]]) – The device to which the network is sent or the list of device to which the network is sent. See to() for details.

Note

The name of each batch and epoch metric can be change by passing a tuple (name, metric) instead of simply the metric function or object, where name is the alternative name of the metric.

Batch and epoch metrics can return multiple metrics (e.g. an epoch metric could return an F1-score with the associated precision and recall). The metrics can returned via an iterable (tuple, list, Numpy arrays, tensors, etc.) or via a mapping (e.g. a dict). However, in this case, the names of the different metric has to be passed in some way. There are two ways to do so. The easiest one is to pass the metric as a tuple (names, metric) where names is a tuple containing a name for each metric returned. Another way is to override the attribute __name__ of the function or object so that it returns a tuple containing a name for all metrics returned. Note that, when the metric returns a mapping, the names of the different metrics must be keys in the mapping.

Example:

# Example with custom batch metrics
my_custom_metric = lambda input, target: 42.
my_custom_metric2 = lambda input, target: torch.tensor([42., 43.])
my_custom_metric3 = lambda input, target: {'a': 42., 'b': 43.}
batch_metrics = [('custom_name', my_custom_metric),
                 (('metric_1', 'metric_2'), my_custom_metric2),
                 (('a', 'b'), my_custom_metric3)]
network

The associated PyTorch network.

Type

torch.nn.Module

optimizer

The associated PyTorch optimizer.

Type

torch.optim.Optimizer

loss_function

The associated loss function.

batch_metrics

The associated metric functions for every batch.

Type

list

epoch_metrics

The associated metric functions for every epoch.

Type

list

Examples

Using Numpy arrays (or tensors) dataset:

from poutyne import Model
import torch
import numpy as np

num_features = 20
num_classes = 5

# Our training dataset with 800 samples.
num_train_samples = 800
train_x = np.random.randn(num_train_samples, num_features).astype('float32')
train_y = np.random.randint(num_classes, size=num_train_samples).astype('int64')

# Our validation dataset with 200 samples.
num_valid_samples = 200
valid_x = np.random.randn(num_valid_samples, num_features).astype('float32')
valid_y = np.random.randint(num_classes, size=num_valid_samples).astype('int64')

pytorch_network = torch.nn.Linear(num_features, num_classes) # Our network

# We create and optimize our model
model = Model(pytorch_network, 'sgd', 'cross_entropy', batch_metrics=['accuracy'])
model.fit(train_x, train_y,
          validation_data=(valid_x, valid_y),
          epochs=5,
          batch_size=32)
Epoch 1/5 0.02s Step 25/25: loss: 1.719885, acc: 19.375000, val_loss: 1.667446, val_acc: 22.000000
Epoch 2/5 0.02s Step 25/25: loss: 1.705489, acc: 19.750000, val_loss: 1.660806, val_acc: 22.000000
Epoch 3/5 0.01s Step 25/25: loss: 1.692345, acc: 19.625000, val_loss: 1.655008, val_acc: 22.500000
...

Using PyTorch DataLoader:

import torch
from torch.utils.data import DataLoader, TensorDataset
from poutyne import Model

num_features = 20
num_classes = 5

# Our training dataset with 800 samples.
num_train_samples = 800
train_x = torch.rand(num_train_samples, num_features)
train_y = torch.randint(num_classes, (num_train_samples,), dtype=torch.long)
train_dataset = TensorDataset(train_x, train_y)
train_generator = DataLoader(train_dataset, batch_size=32)

# Our validation dataset with 200 samples.
num_valid_samples = 200
valid_x = torch.rand(num_valid_samples, num_features)
valid_y = torch.randint(num_classes, (num_valid_samples,), dtype=torch.long)
valid_dataset = TensorDataset(valid_x, valid_y)
valid_generator = DataLoader(valid_dataset, batch_size=32)

pytorch_network = torch.nn.Linear(num_features, num_train_samples)

model = Model(pytorch_network, 'sgd', 'cross_entropy', batch_metrics=['accuracy'])
model.fit_generator(train_generator,
                    valid_generator,
                    epochs=5)
Epoch 1/5 0.05s Step 25/25: loss: 6.752676, acc: 0.000000, val_loss: 6.575071, val_acc: 0.000000
Epoch 2/5 0.03s Step 25/25: loss: 6.454859, acc: 0.125000, val_loss: 6.279577, val_acc: 0.000000
Epoch 3/5 0.03s Step 25/25: loss: 6.158523, acc: 2.125000, val_loss: 5.985811, val_acc: 9.500000
...
fit(x, y, validation_data=None, *, batch_size=32, epochs=1000, steps_per_epoch=None, validation_steps=None, batches_per_step=1, initial_epoch=1, verbose=True, progress_options: Optional[dict] = None, callbacks=None, dataloader_kwargs=None)[source]

Trains the network on a dataset. This method creates generators and calls the fit_generator() method.

Parameters
  • x (Union[Tensor, ndarray] or Union[tuple, list] of Union[Tensor, ndarray]) – Training dataset. Union[Tensor, ndarray] if the model has a single input. Union[tuple, list] of Union[Tensor, ndarray] if the model has multiple inputs.

  • y (Union[Tensor, ndarray] or Union[tuple, list] of Union[Tensor, ndarray]) – Target. Union[Tensor, ndarray] if the model has a single output. Union[tuple, list] of Union[Tensor, ndarray] if the model has multiple outputs.

  • validation_data (Tuple[x_val, y_val]) – Same format as x and y previously described. Validation dataset on which to evaluate the loss and any model metrics at the end of each epoch. The model will not be trained on this data. (Default value = None)

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • epochs (int) – Number of times the entire training dataset is seen. (Default value = 1000)

  • steps_per_epoch (int, optional) – Number of batch used during one epoch. Obviously, using this argument may cause one epoch not to see the entire training dataset or see it multiple times. (Defaults the number of steps needed to see the entire training dataset)

  • validation_steps (int, optional) – Same as for steps_per_epoch but for the validation dataset. (Defaults to the number of steps needed to see the entire validation dataset)

  • batches_per_step (int) – Number of batches on which to compute the running loss before backpropagating it through the network. Note that the total loss used for backpropagation is the mean of the batches_per_step batch losses. (Default value = 1)

  • initial_epoch (int, optional) – Epoch at which to start training (useful for resuming a previous training run). (Default value = 1)

  • verbose (bool) – Whether to display the progress of the training. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None)

  • callbacks (List[Callback]) – List of callbacks that will be called during training. (Default value = None)

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally. By default, shuffle=True is passed for the training dataloader but this can be overridden by using this argument.

Returns

List of dict containing the history of each epoch.

Example

model = Model(pytorch_network, optimizer, loss_function)
history = model.fit(train_x, train_y,
                    validation_data=(valid_x, valid_y)
                    epochs=num_epochs,
                    batch_size=batch_size,
                    verbose=False)
print(*history, sep="\n")
{'epoch': 1, 'loss': 1.7198852968215943, 'time': 0.019999928001197986, 'acc': 19.375, 'val_loss': 1.6674459838867188, 'val_acc': 22.0}
{'epoch': 2, 'loss': 1.7054892110824584, 'time': 0.015421080999658443, 'acc': 19.75, 'val_loss': 1.660806336402893, 'val_acc': 22.0}
{'epoch': 3, 'loss': 1.6923445892333984, 'time': 0.01363091799794347, 'acc': 19.625, 'val_loss': 1.6550078630447387, 'val_acc': 22.5}
...
fit_dataset(train_dataset, valid_dataset=None, *, batch_size=32, epochs=1000, steps_per_epoch=None, validation_steps=None, batches_per_step=1, initial_epoch=1, verbose=True, progress_options=None, callbacks=None, num_workers=0, collate_fn=None, dataloader_kwargs=None)[source]

Trains the network on a dataset. This method creates dataloaders and calls the fit_generator() method.

Parameters
  • train_dataset (Dataset) – Training dataset.

  • valid_dataset (Dataset) – Validation dataset.

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • epochs (int) – Number of times the entire training dataset is seen. (Default value = 1000)

  • steps_per_epoch (int, optional) – Number of batch used during one epoch. Obviously, using this argument may cause one epoch not to see the entire training dataset or see it multiple times. (Defaults the number of steps needed to see the entire training dataset)

  • validation_steps (int, optional) – Same as for steps_per_epoch but for the validation dataset. (Defaults to the number of steps needed to see the entire validation dataset)

  • batches_per_step (int) – Number of batches on which to compute the running loss before backpropagating it through the network. Note that the total loss used for backpropagation is the mean of the batches_per_step batch losses. (Default value = 1)

  • initial_epoch (int, optional) – Epoch at which to start training (useful for resuming a previous training run). (Default value = 1)

  • verbose (bool) – Whether to display the progress of the training. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None)

  • callbacks (List[Callback]) – List of callbacks that will be called during training. (Default value = None)

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally. By default, shuffle=True is passed for the training dataloader but this can be overridden by using this argument.

  • num_workers (int, optional) – how many subprocesses to use for data loading. 0 means that the data will be loaded in the main process. (Default value = 0)

  • collate_fn (Callable, optional) – merges a list of samples to form a mini-batch of Tensor(s). Used when using batched loading from a map-style dataset.

Returns

List of dict containing the history of each epoch.

See DataLoader for details on batch_size, num_workers and collate_fn.

Example

model = Model(pytorch_network, optimizer, loss_function)
history = model.fit(train_dataset,
                    valid_dataset,
                    epochs=num_epochs,
                    batch_size=batch_size,
                    verbose=False)
print(*history, sep="\n")
{'epoch': 1, 'loss': 1.7198852968215943, 'time': 0.019999928001197986, 'acc': 19.375, 'val_loss': 1.6674459838867188, 'val_acc': 22.0}
{'epoch': 2, 'loss': 1.7054892110824584, 'time': 0.015421080999658443, 'acc': 19.75, 'val_loss': 1.660806336402893, 'val_acc': 22.0}
{'epoch': 3, 'loss': 1.6923445892333984, 'time': 0.01363091799794347, 'acc': 19.625, 'val_loss': 1.6550078630447387, 'val_acc': 22.5}
...
fit_generator(train_generator, valid_generator=None, *, epochs=1000, steps_per_epoch=None, validation_steps=None, batches_per_step=1, initial_epoch=1, verbose=True, progress_options: Optional[dict] = None, callbacks=None)[source]

Trains the network on a dataset using a generator.

Parameters
  • train_generator

    Generator-like object for the training dataset. The generator must yield a batch in the form of a tuple (x, y) where x is the input and y is the target. The batch size is inferred from x and y. See get_batch_size() for details on the inferring algorithm. The loss and the metrics are averaged using this batch size. If the batch size cannot be inferred then a warning is raised and the “batch size” defaults to 1.

    If the generator does not have a method __len__(), either the steps_per_epoch argument must be provided, or the iterator returned raises a StopIteration exception at the end of the training dataset. PyTorch DataLoaders object do provide a __len__() method.

    Before each epoch, the method __iter__() on the generator is called and the method __next__() is called for each step on resulting object returned by __iter__(). Notice that a call to __iter__() on a generator made using the python keyword yield returns the generator itself.

  • valid_generator (optional) – Generator-like object for the validation dataset. This generator is optional. The generator is used the same way as the generator train_generator. If the generator does not have a method __len__(), either the validation_steps or the steps_per_epoch argument must be provided or the iterator returned raises a StopIteration exception at the end of the validation dataset. (Default value = None)

  • epochs (int) – Number of times the entire training dataset is seen. (Default value = 1000)

  • steps_per_epoch (int, optional) – Number of batch used during one epoch. Obviously, using this argument may cause one epoch not to see the entire training dataset or see it multiple times. See argument train_generator and valid_generator for more details of how steps_per_epoch is used.

  • validation_steps (int, optional) – Same as for steps_per_epoch but for the validation dataset. See argument valid_generator for more details of how validation_steps is used.

  • batches_per_step (int) – Number of batches on which to compute the running loss before backpropagating it through the network. Note that the total loss used for backpropagation is the mean of the batches_per_step batch losses. (Default value = 1)

  • initial_epoch (int, optional) – Epoch at which to start training (useful for resuming a previous training run). (Default value = 1)

  • verbose (bool) – Whether to display the progress of the training. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • callbacks (List[Callback]) – List of callbacks that will be called during training. (Default value = None)

Returns

List of dict containing the history of each epoch.

Example

model = Model(pytorch_network, optimizer, loss_function)
history = model.fit_generator(train_generator,
                              valid_generator,
                              epochs=num_epochs,
                              verbose=False)
print(*history, sep="\n")
{'epoch': 1, 'loss': 1.7198852968215943, 'time': 0.019999928001197986, 'acc': 19.375, 'val_loss': 1.6674459838867188, 'val_acc': 22.0}
{'epoch': 2, 'loss': 1.7054892110824584, 'time': 0.015421080999658443, 'acc': 19.75, 'val_loss': 1.660806336402893, 'val_acc': 22.0}
{'epoch': 3, 'loss': 1.6923445892333984, 'time': 0.01363091799794347, 'acc': 19.625, 'val_loss': 1.6550078630447387, 'val_acc': 22.5}
...
train_on_batch(x, y, return_pred=False, return_dict_format=False)[source]

Trains the network for the batch (x, y) and computes the loss and the metrics, and optionally returns the predictions.

Parameters
  • x – Input data as a batch.

  • y – Target data as a batch.

  • return_pred (bool, optional) – Whether to return the predictions. (Default value = False)

  • return_dict_format (bool, optional) – Whether to return the loss and metrics in a dict format or not. (Default value = False)

Returns

Float loss if no metrics were specified and return_pred is false.

Otherwise, tuple (loss, metrics) if return_pred is false. metrics is a Numpy array of size n, where n is the number of metrics if n > 1. If n == 1, then metrics is a float. If n == 0, the metrics is omitted.

Tuple (loss, metrics, pred_y) if return_pred is true where pred_y is the predictions with tensors converted into Numpy arrays.

If return_dict_format is True, then loss, metrics are replaced by a dictionary.

predict(x, *, batch_size=32, verbose=True, progress_options: Optional[dict] = None, callbacks=None, dataloader_kwargs=None) Any[source]

Returns the predictions of the network given a dataset x, where the tensors are converted into Numpy arrays.

Parameters
  • x (Union[Tensor, ndarray] or Union[tuple, list] of Union[Tensor, ndarray]) – Input to the model. Union[Tensor, ndarray] if the model has a single input. Union[tuple, list] of Union[Tensor, ndarray] if the model has multiple inputs.

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally.

Returns

Return the predictions in the format outputted by the model.

predict_dataset(dataset, *, batch_size=32, steps=None, has_ground_truth=False, return_ground_truth=False, concatenate_returns=True, num_workers=0, collate_fn=None, verbose=True, progress_options: Optional[dict] = None, callbacks=None, dataloader_kwargs=None) Any[source]

Returns the predictions of the network given a dataset x, where the tensors are converted into Numpy arrays.

Parameters
  • dataset (Dataset) – Dataset. Must not return y, just x, unless has_ground_truth is true.

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • steps (int, optional) – Number of iterations done on generator. (Defaults the number of steps needed to see the entire dataset)

  • has_ground_truth (bool, optional) – Whether the generator yields the target y. Automatically set to true if return_ground_truth is true. (Default value = False)

  • return_ground_truth (bool, optional) – Whether to return the ground truths. If true, automatically set has_ground_truth to true. (Default value = False)

  • concatenate_returns (bool, optional) – Whether to concatenate the predictions or the ground truths when returning them. See predict_generator() for details. (Default value = True)

  • num_workers (int, optional) – how many subprocesses to use for data loading. 0 means that the data will be loaded in the main process. (Default value = 0)

  • collate_fn (Callable, optional) – merges a list of samples to form a mini-batch of Tensor(s). Used when using batched loading from a map-style dataset.

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally.

Returns

Depends on the value of concatenate_returns. By default, (concatenate_returns is true), the data structures (tensor, tuple, list, dict) returned as predictions for the batches are merged together. In the merge, the tensors are converted into Numpy arrays and are then concatenated together. If concatenate_returns is false, then a list of the predictions for the batches is returned with tensors converted into Numpy arrays.

See:

DataLoader for details on batch_size, num_workers and collate_fn.

predict_generator(generator, *, steps=None, has_ground_truth=False, return_ground_truth=False, concatenate_returns=True, verbose=True, progress_options: Optional[dict] = None, callbacks=None) Any[source]

Returns the predictions of the network given batches of samples x, where the tensors are converted into Numpy arrays.

Parameters
  • generator – Generator-like object for the dataset. The generator must yield a batch of samples. See the fit_generator() method for details on the types of generators supported. This should only yield input data x and NOT the target y, unless has_ground_truth is true.

  • steps (int, optional) – Number of iterations done on generator. (Defaults the number of steps needed to see the entire dataset)

  • has_ground_truth (bool, optional) – Whether the generator yields the target y. Automatically set to true if return_ground_truth is true. (Default value = False)

  • return_ground_truth (bool, optional) – Whether to return the ground truths. If true, automatically set has_ground_truth to true. (Default value = False)

  • concatenate_returns (bool, optional) – Whether to concatenate the predictions or the ground truths when returning them. (Default value = True)

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

Returns

Depends on the value of concatenate_returns. By default, (concatenate_returns is true), the data structures (tensor, tuple, list, dict) returned as predictions for the batches are merged together. In the merge, the tensors are converted into Numpy arrays and are then concatenated together. If concatenate_returns is false, then a list of the predictions for the batches is returned with tensors converted into Numpy arrays.

predict_on_batch(x) Any[source]

Returns the predictions of the network given a batch x, where the tensors are converted into Numpy arrays.

Parameters

x – Input data as a batch.

Returns

Return the predictions in the format outputted by the model.

evaluate(x, y, *, batch_size=32, return_pred=False, return_dict_format=False, callbacks=None, verbose=True, progress_options: Optional[dict] = None, dataloader_kwargs=None) Tuple[source]

Computes the loss and the metrics of the network on batches of samples and optionally returns the predictions.

Parameters
  • x (Union[Tensor, ndarray] or Union[tuple, list] of Union[Tensor, ndarray]) – Input to the model. Union[Tensor, ndarray] if the model has a single input. Union[tuple, list] of Union[Tensor, ndarray] if the model has multiple inputs.

  • y (Union[Tensor, ndarray] or Union[tuple, list] of Union[Tensor, ndarray]) – Target, corresponding ground truth. Union[Tensor, ndarray] if the model has a single output. Union[tuple, list] of Union[Tensor, ndarray] if the model has multiple outputs.

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • return_pred (bool, optional) – Whether to return the predictions. (Default value = False)

  • return_dict_format (bool, optional) – Whether to return the loss and metrics in a dict format or not. (Default value = False)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally.

Returns

Tuple (loss, metrics, pred_y) where specific elements are omitted if not applicable. If only loss is applicable, then it is returned as a float.

metrics is a Numpy array of size n, where n is the number of batch metrics plus the number of epoch metrics if n > 1. If n == 1, then metrics is a float. If n == 0, the metrics is omitted. The first elements of metrics are the batch metrics and are followed by the epoch metrics. See the fit_generator() method for examples with batch metrics and epoch metrics.

If return_pred is True, pred_y is the list of the predictions of each batch with tensors converted into Numpy arrays. It is otherwise omitted.

If return_dict_format is True, then loss, metrics are replaced by a dictionary as passed to on_test_end().

evaluate_dataset(dataset, *, batch_size=32, steps=None, return_pred=False, return_ground_truth=False, return_dict_format=False, concatenate_returns=True, callbacks=None, num_workers=0, collate_fn=None, dataloader_kwargs=None, verbose=True, progress_options: Optional[dict] = None) Tuple[source]

Computes the loss and the metrics of the network on batches of samples and optionally returns the predictions.

Parameters
  • dataset (Dataset) – Dataset.

  • batch_size (int) – Number of samples given to the network at one time. (Default value = 32)

  • steps (int, optional) – Number of batches used for evaluation. (Defaults the number of steps needed to see the entire dataset)

  • return_pred (bool, optional) – Whether to return the predictions. (Default value = False)

  • return_ground_truth (bool, optional) – Whether to return the ground truths. (Default value = False)

  • return_dict_format (bool, optional) – Whether to return the loss and metrics in a dict format or not. (Default value = False)

  • concatenate_returns (bool, optional) – Whether to concatenate the predictions or the ground truths when returning them. (Default value = True)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

  • num_workers (int, optional) – how many subprocesses to use for data loading. 0 means that the data will be loaded in the main process. (Default value = 0)

  • collate_fn (Callable, optional) – merges a list of samples to form a mini-batch of Tensor(s). Used when using batched loading from a map-style dataset.

  • dataloader_kwargs (dict, optional) – Keyword arguments to pass to the PyTorch dataloaders created internally.

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

Returns

Tuple (loss, metrics, pred_y) where specific elements are omitted if not applicable. If only loss is applicable, then it is returned as a float.

metrics is a Numpy array of size n, where n is the number of batch metrics plus the number of epoch metrics if n > 1. If n == 1, then metrics is a float. If n == 0, the metrics is omitted. The first elements of metrics are the batch metrics and are followed by the epoch metrics. See the fit_generator() method for examples with batch metrics and epoch metrics.

If return_pred is True, pred_y is the list of the predictions of each batch with tensors converted into Numpy arrays. It is otherwise omitted.

If return_dict_format is True, then loss, metrics are replaced by a dictionary as passed to on_test_end().

See:

DataLoader for details on batch_size, num_workers and collate_fn.

evaluate_generator(generator, *, steps=None, return_pred=False, return_ground_truth=False, return_dict_format=False, concatenate_returns=True, verbose=True, progress_options: Optional[dict] = None, callbacks=None) Tuple[source]

Computes the loss and the metrics of the network on batches of samples and optionally returns the predictions.

Parameters
  • generator – Generator-like object for the dataset. See the fit_generator() method for details on the types of generators supported.

  • steps (int, optional) – Number of iterations done on generator. (Defaults the number of steps needed to see the entire dataset)

  • return_pred (bool, optional) – Whether to return the predictions. (Default value = False)

  • return_ground_truth (bool, optional) – Whether to return the ground truths. (Default value = False)

  • return_dict_format (bool, optional) – Whether to return the loss and metrics in a dict format or not. (Default value = False)

  • concatenate_returns (bool, optional) – Whether to concatenate the predictions or the ground truths when returning them. (Default value = True)

  • verbose (bool) – Whether to display the progress of the evaluation. (Default value = True)

  • progress_options (dict, optional) – Keyword arguments to pass to the default progression callback used in Poutyne (See ProgressionCallback for the available arguments). (Default value = None, meaning default color setting and progress bar)

  • callbacks (List[Callback]) – List of callbacks that will be called during testing. (Default value = None)

Returns

Tuple (loss, metrics, pred_y, true_y) where specific elements are omitted if not applicable. If only loss is applicable, then it is returned as a float.

metrics is a Numpy array of size n, where n is the number of batch metrics plus the number of epoch metrics if n > 1. If n == 1, then metrics is a float. If n == 0, the metrics is omitted. The first elements of metrics are the batch metrics and are followed by the epoch metrics.

If return_pred is True, pred_y is the predictions returned as in the predict_generator() method. It is otherwise ommited.

If return_ground_truth is True, true_y is the ground truths returned as in the predict_generator() method. It is otherwise omitted.

If return_dict_format is True, then loss, metrics are replaced by a dictionary as passed to on_test_end().

Example

With no metrics:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=None)
loss = model.evaluate_generator(test_generator)

With only one batch metric:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric_fn])
loss, my_metric = model.evaluate_generator(test_generator)

With several batch metrics:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric1_fn, my_metric2_fn])
loss, (my_metric1, my_metric2) = model.evaluate_generator(test_generator)

With one batch metric and one epoch metric:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric_fn], epoch_metrics=[MyEpochMetricClass()])
loss, (my_batch_metric, my__epoch_metric) = model.evaluate_generator(test_generator)

With batch metrics and return_pred flag:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric1_fn, my_metric2_fn])
loss, (my_metric1, my_metric2), pred_y = model.evaluate_generator(
    test_generator, return_pred=True
)

With batch metrics, return_pred and return_ground_truth flags:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric1_fn, my_metric2_fn])
loss, (my_metric1, my_metric2), pred_y, true_y = model.evaluate_generator(
    test_generator, return_pred=True, return_ground_truth=True
)

With return_dict_format:

model = Model(pytorch_network, optimizer, loss_function,
              batch_metrics=[my_metric_fn])
logs = model.evaluate_generator(test_generator, return_dict_format=True)
evaluate_on_batch(x, y, *, return_pred=False, return_dict_format=False) Tuple[source]

Computes the loss and the metrics of the network on a single batch of samples and optionally returns the predictions.

Parameters
  • x – Input data as a batch.

  • y – Target data as a batch.

  • return_pred (bool, optional) – Whether to return the predictions for batch. (Default value = False)

  • return_dict_format (bool, optional) – Whether to return the loss and metrics in a dict format or not. (Default value = False)

Returns

Tuple (loss, metrics, pred_y) where specific elements are omitted if not applicable. If only loss is applicable, then it is returned as a float.

metrics` is a Numpy array of size n, where n is the number of metrics if n > 1. If n == 1, then metrics is a float. If n == 0, the metrics is omitted.

If return_pred is True, pred_y is the list of the predictions of each batch with tensors converted into Numpy arrays. It is otherwise omitted.

If return_dict_format is True, then loss, metrics are replaced by a dictionary.

get_batch_size(x, y)[source]

This method infers the batch size of a batch. Here is the inferring algorithm used to compute the batch size. x and y are tested in this order at each step of the inferring algorithm. If one step succeed for one of x or y, the algorithm stops.

  • Step 1: if x or y is a tensor or a Numpy array, then the len() is returned.

  • Step 2: if x or y is a list or a tuple, then the len() of the first element is returned if it is a tensor or a Numpy array.

  • Step 3: if x or y is a dict, then the value for the key 'batch_size' is returned if it is of integral type.

  • Step 4: if x or y is a dict, then the len() of the first element of .values() is returned if it is a tensor or a Numpy array.

If inferring the batch size is not possible, the batch size is set to 1 and, thus, the computed loss and metrics at the end of each epoch is the mean of the batches’ losses and metrics. In which case, a warning is also raised. To disable this warning, set

from poutyne import warning_settings

warning_settings['batch_size'] = 'ignore'
Parameters
  • x – Input data as a batch.

  • y – Target data as a batch.

load_weights(f, strict=True)[source]

Loads the weights saved using the torch.save() method or the save_weights() method of this class. Contrary to torch.load(), the weights are not transferred to the device from which they were saved from. In other words, the PyTorch module will stay on the same device it already is on.

Parameters

f – File-like object (has to implement fileno that returns a file descriptor) or string containing a file name.

Returns

  • missing_keys is a list of str containing the missing keys

  • unexpected_keys is a list of str containing the unexpected keys

Return type

NamedTuple with missing_keys and unexpected_keys fields

save_weights(f)[source]

Saves the weights of the current network.

Parameters

f – File-like object (has to implement fileno that returns a file descriptor) or string containing a file name.

load_optimizer_state(f)[source]

Loads the optimizer state saved using the torch.save() method or the save_optimizer_state() method of this class.

Parameters

f – File-like object (has to implement fileno that returns a file descriptor) or string containing a file name.

save_optimizer_state(f)[source]

Saves the state of the current optimizer.

Parameters

f – File-like object (has to implement fileno that returns a file descriptor) or string containing a file name.

get_weights()[source]

Returns a dictionary containing the parameters of the network. The tensors are just references to the parameters. To get copies of the weights, see the get_weight_copies() method.

get_weight_copies()[source]

Returns a dictionary containing copies of the parameters of the network.

set_weights(weights, strict=True)[source]

Modifies the weights of the network with the given weights.

Parameters

weights (dict) – Weights returned by either get_weights() or get_weight_copies().

Returns

  • missing_keys is a list of str containing the missing keys

  • unexpected_keys is a list of str containing the unexpected keys

Return type

NamedTuple with missing_keys and unexpected_keys fields

cuda(*args, **kwargs)[source]

Transfers the network on the GPU. The arguments are passed to the torch.nn.Module.cuda() method. Notice that the device is saved so that the batches can send to the right device before passing it to the network.

Note

PyTorch optimizers assume that the parameters have been transferred to the right device before their creations. Furthermore, future versions of PyTorch will no longer modify the parameters of a PyTorch module in-place when transferring them to another device. See this issue and this pull request for details.

Since Poutyne supposes that the optimizer has been initialized before the Poutyne Model, necessarily the parameters are not guaranteed to be in sync with those contained in the optimizer once the PyTorch module is transferred to another device. Thus, this method takes care of this inconsistency by updating the parameters inside the optimizer.

Returns

self.

cpu(*args, **kwargs)[source]

Transfers the network on the CPU. The arguments are passed to the torch.nn.Module.cpu() method. Notice that the device is saved so that the batches can send to the right device before passing it to the network.

Note

PyTorch optimizers assume that the parameters have been transferred to the right device before their creations. Furthermore, future versions of PyTorch will no longer modify the parameters of a PyTorch module in-place when transferring them to another device. See this issue and this pull request for details.

Since Poutyne supposes that the optimizer has been initialized before the Poutyne Model, necessarily the parameters are not guaranteed to be in sync with those contained in the optimizer once the PyTorch module is transferred to another device. Thus, this method takes care of this inconsistency by updating the parameters inside the optimizer.

Returns

self.

to(device)[source]

Transfer the network on the specified device. The device is saved so that the batches can send to the right device before passing it to the network. One could also use multi GPUs by using either a list of devices or “all” to take all the available devices. In both cases, the training loop will use the ~torch.nn.parallel.data_parallel() function for single node multi GPUs parallel process and the main device is the first device.

Note

PyTorch optimizers assume that the parameters have been transferred to the right device before their creations. Furthermore, future versions of PyTorch will no longer modify the parameters of a PyTorch module in-place when transferring them to another device. See this issue and this pull request for details.

Since Poutyne supposes that the optimizer has been initialized before the Poutyne Model, necessarily the parameters are not guaranteed to be in sync with those contained in the optimizer once the PyTorch module is transferred to another device. Thus, this method takes care of this inconsistency by updating the parameters inside the optimizer.

Parameters
Returns

self.