def __init__(
self,
cell_type: str = "LSTM",
hidden_size: int = 10,
rnn_layers: int = 2,
dropout: float = 0.1,
static_categoricals: List[str] = [],
static_reals: List[str] = [],
time_varying_categoricals_encoder: List[str] = [],
time_varying_categoricals_decoder: List[str] = [],
categorical_groups: Dict[str, List[str]] = {},
time_varying_reals_encoder: List[str] = [],
time_varying_reals_decoder: List[str] = [],
embedding_sizes: Dict[str, Tuple[int, int]] = {},
embedding_paddings: List[str] = [],
embedding_labels: Dict[str, np.ndarray] = {},
x_reals: List[str] = [],
x_categoricals: List[str] = [],
n_validation_samples: int = None,
n_plotting_samples: int = None,
target: Union[str, List[str]] = None,
loss: DistributionLoss = None,
logging_metrics: nn.ModuleList = None,
**kwargs,
):
"""
DeepAR Network.
The code is based on the article `DeepAR: Probabilistic forecasting with autoregressive recurrent networks
<https://www.sciencedirect.com/science/article/pii/S0169207019301888>`_.
Args:
cell_type (str, optional): Recurrent cell type ["LSTM", "GRU"]. Defaults to "LSTM".
hidden_size (int, optional): hidden recurrent size - the most important hyperparameter along with
``rnn_layers``. Defaults to 10.
rnn_layers (int, optional): Number of RNN layers - important hyperparameter. Defaults to 2.
dropout (float, optional): Dropout in RNN layers. Defaults to 0.1.
static_categoricals: integer of positions of static categorical variables
static_reals: integer of positions of static continuous variables
time_varying_categoricals_encoder: integer of positions of categorical variables for encoder
time_varying_categoricals_decoder: integer of positions of categorical variables for decoder
time_varying_reals_encoder: integer of positions of continuous variables for encoder
time_varying_reals_decoder: integer of positions of continuous variables for decoder
categorical_groups: dictionary where values
are list of categorical variables that are forming together a new categorical
variable which is the key in the dictionary
x_reals: order of continuous variables in tensor passed to forward function
x_categoricals: order of categorical variables in tensor passed to forward function
embedding_sizes: dictionary mapping (string) indices to tuple of number of categorical classes and
embedding size
embedding_paddings: list of indices for embeddings which transform the zero's embedding to a zero vector
embedding_labels: dictionary mapping (string) indices to list of categorical labels
n_validation_samples (int, optional): Number of samples to use for calculating validation metrics.
Defaults to None, i.e. no sampling at validation stage and using "mean" of distribution for logging
metrics calculation.
n_plotting_samples (int, optional): Number of samples to generate for plotting predictions
during training. Defaults to ``n_validation_samples`` if not None or 100 otherwise.
target (str, optional): Target variable or list of target variables. Defaults to None.
loss (DistributionLoss, optional): Distribution loss function. Keep in mind that each distribution
loss function might have specific requirements for target normalization.
Defaults to :py:class:`~pytorch_forecasting.metrics.NormalDistributionLoss`.
logging_metrics (nn.ModuleList, optional): Metrics to log during training.
Defaults to nn.ModuleList([SMAPE(), MAE(), RMSE(), MAPE(), MASE()]).
"""
if loss is None:
loss = NormalDistributionLoss()
if logging_metrics is None:
logging_metrics = nn.ModuleList(
[SMAPE(), MAE(), RMSE(),
MAPE(), MASE()])
if n_plotting_samples is None:
if n_validation_samples is None:
n_plotting_samples = n_validation_samples
else:
n_plotting_samples = 100
self.save_hyperparameters()
# store loss function separately as it is a module
super().__init__(loss=loss, logging_metrics=logging_metrics, **kwargs)
self.embeddings = MultiEmbedding(
embedding_sizes=embedding_sizes,
embedding_paddings=embedding_paddings,
categorical_groups=categorical_groups,
x_categoricals=x_categoricals,
)
assert set(self.encoder_variables) - set(to_list(target)) == set(
self.decoder_variables
), "Encoder and decoder variables have to be the same apart from target variable"
for targeti in to_list(target):
assert (
targeti in time_varying_reals_encoder
), f"target {targeti} has to be real" # todo: remove this restriction
assert (
isinstance(target, str) and isinstance(loss, DistributionLoss)
) or (
isinstance(target,
(list, tuple)) and isinstance(loss, MultiLoss) and
len(loss)
== len(target)
), "number of targets should be equivalent to number of loss metrics"
time_series_rnn = get_cell(cell_type)
self.rnn = time_series_rnn(
input_size=self.input_size,
hidden_size=self.hparams.hidden_size,
num_layers=self.hparams.rnn_layers,
dropout=self.hparams.dropout if self.hparams.rnn_layers > 1 else 0,
batch_first=True,
)
# add linear layers for argument projects
if isinstance(loss, MultiLoss): # multi target
self.distribution_projector = nn.ModuleList([
nn.Linear(self.hparams.hidden_size, len(args))
for args in self.loss.distribution_arguments
])
else:
self.distribution_projector = nn.Linear(
self.hparams.hidden_size,
len(self.loss.distribution_arguments))
def test_get_gru_cell():
cell = get_cell("GRU")(10, 10)
assert isinstance(cell, TimeSeriesGRU)
assert isinstance(cell, nn.GRU)
def test_get_cell_raises_value_error():
pytest.raises(ValueError, lambda: get_cell("ABCDEF"))
def test_get_lstm_cell():
cell = get_cell("LSTM")(10, 10)
assert isinstance(cell, TimeSeriesLSTM)
assert isinstance(cell, nn.LSTM)