Files
pytorch-ts/pts/model/deepar/deepar_network.py
T

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2.8 KiB
Python

from typing import List
import torch
import torch.nn as nn
import numpy as np
from pts.modules import DistributionOutput, MeanScaler, NOPScaler, FeatureEmbedder
class DeepARNetwork(nn.Module):
def __init__(
self,
num_layers: int,
num_cells: int,
cell_type: str,
history_length: int,
context_length: int,
prediction_length: int,
distr_output: DistributionOutput,
dropout_rate: float,
cardinality: List[int],
embedding_dimension: List[int],
lags_seq: List[int],
scaling: bool = True,
dtype: np.dtype = np.float32,
) -> None:
super().__init__()
self.num_layers = num_layers
self.num_cells = num_cells
self.cell_type = cell_type
self.history_length = history_length
self.context_length = context_length
self.prediction_length = prediction_length
self.dropout_rate = dropout_rate
self.cardinality = cardinality
self.embedding_dimension = embedding_dimension
self.num_cat = len(cardinality)
self.scaling = scaling
self.dtype = dtype
self.lags_seq = lags_seq
self.distr_output = distr_output
rnn = {"LSTM": nn.LSTM, "GRU": nn.GRU}[
self.cell_type
]
self.rnn = rnn(
input_size=1,
hidden_size=num_cells,
num_layers=num_layers,
dropout=dropout_rate,
batch_first=True
)
# TODO
# self.target_shape = distr_output.event_shape
self.proj_distr_args = distr_output.get_args_proj()
self.embedder = FeatureEmbedder(
cardinalities=cardinality,
embedding_dims=embedding_dimension
)
if scaling:
self.scaler = MeanScaler(keepdim=True)
else:
self.scaler = NOPScaler(keepdim=True)
@staticmethod
def get_lagged_subsequences(
sequence: torch.Tensor,
sequence_length: int,
indices: List[int],
subsequences_length: int = 1,
) -> torch.Tensor:
assert max(indices) + subsequences_length <= sequence_length, (
f"lags cannot go further than history length, found lag {max(indices)} "
f"while history length is only {sequence_length}"
)
assert all(lag_index >= 0 for lag_index in indices)
lagged_values = []
for lag_index in indices:
begin_index = -lag_index - subsequences_length
end_index = -lag_index if lag_index > 0 else None
lagged_values.append(
sequence[:,begin_index:end_index,...]
)
return torch.stack(lagged_values, dim=-1)
class DeepARTrainingNetwork(DeepARNetwork):
pass