Files
2020-12-17 17:04:56 +01:00

90 lines
2.8 KiB
Python

from typing import List, Optional
import torch
import torch.nn as nn
class FeatureEmbedder(nn.Module):
def __init__(
self,
cardinalities: List[int],
embedding_dims: List[int],
) -> None:
super().__init__()
self.__num_features = len(cardinalities)
def create_embedding(c: int, d: int) -> nn.Embedding:
embedding = nn.Embedding(c, d)
return embedding
self.__embedders = nn.ModuleList(
[create_embedding(c, d) for c, d in zip(cardinalities, embedding_dims)]
)
def forward(self, features: torch.Tensor) -> torch.Tensor:
if self.__num_features > 1:
# we slice the last dimension, giving an array of length
# self.__num_features with shape (N,T) or (N)
cat_feature_slices = torch.chunk(features, self.__num_features, dim=-1)
else:
cat_feature_slices = [features]
return torch.cat(
[
embed(cat_feature_slice.squeeze(-1))
for embed, cat_feature_slice in zip(
self.__embedders, cat_feature_slices
)
],
dim=-1,
)
class FeatureAssembler(nn.Module):
def __init__(
self,
T: int,
embed_static: Optional[FeatureEmbedder] = None,
embed_dynamic: Optional[FeatureEmbedder] = None,
) -> None:
super().__init__()
self.T = T
self.embeddings = nn.ModuleDict(
{"embed_static": embed_static, "embed_dynamic": embed_dynamic}
)
def forward(
self,
feat_static_cat: torch.Tensor,
feat_static_real: torch.Tensor,
feat_dynamic_cat: torch.Tensor,
feat_dynamic_real: torch.Tensor,
) -> torch.Tensor:
processed_features = [
self.process_static_cat(feat_static_cat),
self.process_static_real(feat_static_real),
self.process_dynamic_cat(feat_dynamic_cat),
self.process_dynamic_real(feat_dynamic_real),
]
return torch.cat(processed_features, dim=-1)
def process_static_cat(self, feature: torch.Tensor) -> torch.Tensor:
if self.embeddings["embed_static"] is not None:
feature = self.embeddings["embed_static"](feature)
return feature.unsqueeze(1).expand(-1, self.T, -1).float()
def process_dynamic_cat(self, feature: torch.Tensor) -> torch.Tensor:
if self.embeddings["embed_dynamic"] is None:
return feature.float()
else:
return self.embeddings["embed_dynamic"](feature)
def process_static_real(self, feature: torch.Tensor) -> torch.Tensor:
return feature.unsqueeze(1).expand(-1, self.T, -1)
def process_dynamic_real(self, feature: torch.Tensor) -> torch.Tensor:
return feature