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pytorch-transformer-ts/pyraformer/module.py
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2022-06-15 11:41:08 +02:00

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23 KiB
Python

from typing import List, Optional
import torch
import torch.nn as nn
from gluonts.core.component import validated
from gluonts.time_feature import get_lags_for_frequency
from gluonts.torch.distributions import DistributionOutput, StudentTOutput
from gluonts.torch.modules.feature import FeatureEmbedder
from gluonts.torch.modules.scaler import MeanScaler, NOPScaler
from pyraformer.Layers import EncoderLayer, Predictor, Decoder
from pyraformer.Layers import (
Bottleneck_Construct,
Conv_Construct,
MaxPooling_Construct,
AvgPooling_Construct,
)
from pyraformer.Layers import (
get_mask,
refer_points,
get_k_q,
get_q_k,
get_subsequent_mask,
)
from pyraformer.embed import SingleStepEmbedding, DataEmbedding, CustomEmbedding
class EncoderSS(nn.Module):
@validated()
def __init__(
self,
covariate_size,
num_seq,
input_size,
dropout,
d_model,
d_inner_hid,
d_k,
d_v,
num_heads,
n_layer,
loss,
window_size,
inner_size,
use_tvm,
prediction_length,
device,
):
super().__init__()
self.d_model = d_model
self.window_size = window_size
self.num_heads = num_heads
self.mask, self.all_size = get_mask(input_size, window_size, inner_size, device)
self.indexes = refer_points(self.all_size, window_size, device)
if use_tvm:
assert (
len(set(self.window_size)) == 1
), "Only constant window size is supported."
q_k_mask = get_q_k(input_size, inner_size, window_size[0], device)
k_q_mask = get_k_q(q_k_mask)
self.layers = nn.ModuleList(
[
EncoderLayer(
d_model,
d_inner_hid,
num_heads,
d_k,
d_v,
dropout=dropout,
normalize_before=False,
use_tvm=True,
q_k_mask=q_k_mask,
k_q_mask=k_q_mask,
)
for i in range(n_layer)
]
)
else:
self.layers = nn.ModuleList(
[
EncoderLayer(
d_model,
d_inner_hid,
num_heads,
d_k,
d_v,
dropout=dropout,
normalize_before=False,
)
for i in range(n_layer)
]
)
self.embedding = SingleStepEmbedding(
covariate_size, num_seq, d_model, input_size, device
)
self.conv_layers = Bottleneck_Construct(d_model, window_size, d_k)
def forward(self, sequence):
seq_enc = self.embedding(sequence)
mask = self.mask.repeat(len(seq_enc), self.num_heads, 1, 1).to(sequence.device)
seq_enc = self.conv_layers(seq_enc)
for i in range(len(self.layers)):
seq_enc, _ = self.layers[i](seq_enc, mask)
indexes = self.indexes.repeat(seq_enc.size(0), 1, 1, seq_enc.size(2)).to(
seq_enc.device
)
indexes = indexes.view(seq_enc.size(0), -1, seq_enc.size(2))
all_enc = torch.gather(seq_enc, 1, indexes)
all_enc = all_enc.view(seq_enc.size(0), self.all_size[0], -1)
return all_enc
class PyraformerSSModel(nn.Module):
@validated()
def __init__(
self,
freq,
covariate_size,
num_seq,
input_size,
dropout,
d_model,
d_inner_hid,
d_k,
d_v,
num_heads,
n_layer,
loss,
window_size,
inner_size,
use_tvm,
prediction_length,
context_length,
lags_seq,
num_feat_dynamic_real,
num_feat_static_cat,
num_feat_static_real,
cardinality,
embedding_dimension,
distr_output,
# loss: DistributionLoss = NegativeLogLikelihood(),
scaling,
num_parallel_samples,
device,
):
super().__init__()
self.context_length = context_length
self.lags_seq = lags_seq or get_lags_for_frequency(freq_str=freq)
self.encoder = EncoderSS(
covariate_size,
num_seq,
input_size,
dropout,
d_model,
d_inner_hid,
d_k,
d_v,
num_heads,
n_layer,
loss,
window_size,
inner_size,
use_tvm,
prediction_length,
device,
)
# convert hidden vectors into two scalar
self.mean_hidden = Predictor(4 * d_model, 1)
self.var_hidden = Predictor(4 * d_model, 1)
self.softplus = nn.Softplus()
self.distr_output = distr_output
def forward(self, data):
enc_output = self.encoder(data)
mean_pre = self.mean_hidden(enc_output)
var_hid = self.var_hidden(enc_output)
var_pre = self.softplus(var_hid)
mean_pre = self.softplus(mean_pre)
return mean_pre.squeeze(2), var_pre.squeeze(2)
def test(self, data, v):
mu, sigma = self(data)
sample_mu = mu[:, -1] * v
sample_sigma = sigma[:, -1] * v
return sample_mu, sample_sigma
@property
def _past_length(self) -> int:
return self.context_length + max(self.lags_seq)
@property
def _number_of_features(self) -> int:
return (
sum(self.embedding_dimension)
+ self.num_feat_dynamic_real
+ self.num_feat_static_real
+ 1 # the log(scale)
)
def get_lagged_subsequences(
self, sequence: torch.Tensor, subsequences_length: int, shift: int = 0
) -> torch.Tensor:
"""
Returns lagged subsequences of a given sequence.
Parameters
----------
sequence : Tensor
the sequence from which lagged subsequences should be extracted.
Shape: (N, T, C).
subsequences_length : int
length of the subsequences to be extracted.
shift: int
shift the lags by this amount back.
Returns
--------
lagged : Tensor
a tensor of shape (N, S, C, I), where S = subsequences_length and
I = len(indices), containing lagged subsequences. Specifically,
lagged[i, j, :, k] = sequence[i, -indices[k]-S+j, :].
"""
sequence_length = sequence.shape[1]
indices = [lag - shift for lag in self.lags_seq]
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}"
)
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)
def _check_shapes(
self,
prior_input: torch.Tensor,
inputs: torch.Tensor,
features: Optional[torch.Tensor],
) -> None:
assert len(prior_input.shape) == len(inputs.shape)
assert (
len(prior_input.shape) == 2 and self.input_size == 1
) or prior_input.shape[2] == self.input_size
assert (len(inputs.shape) == 2 and self.input_size == 1) or inputs.shape[
-1
] == self.input_size
assert (
features is None or features.shape[2] == self._number_of_features
), f"{features.shape[2]}, expected {self._number_of_features}"
def create_network_inputs(
self,
feat_static_cat: torch.Tensor,
feat_static_real: torch.Tensor,
past_time_feat: torch.Tensor,
past_target: torch.Tensor,
past_observed_values: torch.Tensor,
future_time_feat: Optional[torch.Tensor] = None,
future_target: Optional[torch.Tensor] = None,
):
# time feature
time_feat = (
torch.cat(
(
past_time_feat[:, self._past_length - self.context_length :, ...],
future_time_feat,
),
dim=1,
)
if future_target is not None
else past_time_feat[:, self._past_length - self.context_length :, ...]
)
# target
context = past_target[:, -self.context_length :]
observed_context = past_observed_values[:, -self.context_length :]
_, scale = self.scaler(context, observed_context)
inputs = (
torch.cat((past_target, future_target), dim=1) / scale
if future_target is not None
else past_target / scale
)
inputs_length = (
self._past_length + self.prediction_length
if future_target is not None
else self._past_length
)
assert inputs.shape[1] == inputs_length
subsequences_length = (
self.context_length + self.prediction_length
if future_target is not None
else self.context_length
)
# embeddings
embedded_cat = self.embedder(feat_static_cat)
static_feat = torch.cat(
(embedded_cat, feat_static_real, scale.log()),
dim=1,
)
expanded_static_feat = static_feat.unsqueeze(1).expand(
-1, time_feat.shape[1], -1
)
features = torch.cat((expanded_static_feat, time_feat), dim=-1)
# self._check_shapes(prior_input, inputs, features)
# sequence = torch.cat((prior_input, inputs), dim=1)
lagged_sequence = self.get_lagged_subsequences(
sequence=inputs,
subsequences_length=subsequences_length,
)
lags_shape = lagged_sequence.shape
reshaped_lagged_sequence = lagged_sequence.reshape(
lags_shape[0], lags_shape[1], -1
)
transformer_inputs = torch.cat((reshaped_lagged_sequence, features), dim=-1)
return transformer_inputs, scale, static_feat
def output_params(self, transformer_inputs):
enc_input = transformer_inputs[:, : self.context_length, ...]
dec_input = transformer_inputs[:, self.context_length :, ...]
enc_out = self.transformer.encoder(enc_input)
dec_output = self.transformer.decoder(
dec_input, enc_out, tgt_mask=self.tgt_mask
)
return self.param_proj(dec_output)
@torch.jit.ignore
def output_distribution(
self, params, scale=None, trailing_n=None
) -> torch.distributions.Distribution:
sliced_params = params
if trailing_n is not None:
sliced_params = [p[:, -trailing_n:] for p in params]
return self.distr_output.distribution(sliced_params, scale=scale)
class Encoder(nn.Module):
@validated()
def __init__(
self,
# model,
window_size,
truncate,
input_size,
inner_size,
decoder,
d_model,
d_k,
d_v,
d_inner_hid,
dropout,
n_layer,
enc_in,
covariate_size,
seq_num,
CSCM,
d_bottleneck,
num_head,
use_tvm,
embed_type,
device,
):
super().__init__()
self.d_model = d_model
# self.model_type = model
self.window_size = window_size
self.truncate = truncate
if decoder == "attention":
self.mask, self.all_size = get_mask(
input_size, window_size, inner_size, device
)
else:
self.mask, self.all_size = get_mask(
input_size + 1, window_size, inner_size, device
)
self.decoder_type = decoder
if decoder == "FC":
self.indexes = refer_points(self.all_size, window_size, device)
if use_tvm:
assert (
len(set(self.window_size)) == 1
), "Only constant window size is supported."
padding = 1 if decoder == "FC" else 0
q_k_mask = get_q_k(input_size + padding, inner_size, window_size[0], device)
k_q_mask = get_k_q(q_k_mask)
self.layers = nn.ModuleList(
[
EncoderLayer(
d_model,
d_inner_hid,
num_head,
d_k,
d_v,
dropout=dropout,
normalize_before=False,
use_tvm=True,
q_k_mask=q_k_mask,
k_q_mask=k_q_mask,
)
for i in range(n_layer)
]
)
else:
self.layers = nn.ModuleList(
[
EncoderLayer(
d_model,
d_inner_hid,
num_head,
d_k,
d_v,
dropout=dropout,
normalize_before=False,
)
for i in range(n_layer)
]
)
if embed_type == "CustomEmbedding":
self.enc_embedding = CustomEmbedding(
enc_in, d_model, covariate_size, seq_num, dropout
)
else:
self.enc_embedding = DataEmbedding(enc_in, d_model, dropout)
self.conv_layers = eval(CSCM)(d_model, window_size, d_bottleneck)
def forward(self, x_enc, x_mark_enc):
seq_enc = self.enc_embedding(x_enc, x_mark_enc)
mask = self.mask.repeat(len(seq_enc), 1, 1).to(x_enc.device)
seq_enc = self.conv_layers(seq_enc)
for i in range(len(self.layers)):
seq_enc, _ = self.layers[i](seq_enc, mask)
if self.decoder_type == "FC":
indexes = self.indexes.repeat(seq_enc.size(0), 1, 1, seq_enc.size(2)).to(
seq_enc.device
)
indexes = indexes.view(seq_enc.size(0), -1, seq_enc.size(2))
all_enc = torch.gather(seq_enc, 1, indexes)
seq_enc = all_enc.view(seq_enc.size(0), self.all_size[0], -1)
elif self.decoder_type == "attention" and self.truncate:
seq_enc = seq_enc[:, : self.all_size[0]]
return seq_enc
class PyraformerLRModel(nn.Module):
@validated()
def __init__(
self,
predict_step,
d_model,
input_size,
decoder,
window_size,
truncate,
d_inner_hid,
d_k,
d_v,
dropout,
enc_in,
covariate_size,
seq_num,
CSCM,
d_bottleneck,
num_head,
n_layer,
inner_size,
use_tvm,
prediction_length,
context_length,
lags_seq,
num_feat_dynamic_real,
num_feat_static_cat,
num_feat_static_real,
cardinality,
embedding_dimension,
num_parallel_samples,
embed_type,
distr_output,
device,
):
super().__init__()
self.predict_step = predict_step
self.d_model = d_model
self.input_size = input_size
self.decoder_type = decoder
self.channels = enc_in
self.distr_output = distr_output
self.context_length = context_length
self.lags_seq = lags_seq
self.encoder = Encoder(
# model,
window_size,
truncate,
input_size,
inner_size,
decoder,
d_model,
d_k,
d_v,
d_inner_hid,
dropout,
n_layer,
enc_in,
covariate_size,
seq_num,
CSCM,
d_bottleneck,
num_head,
use_tvm,
embed_type,
device,
)
if decoder == "attention":
mask = get_subsequent_mask(input_size, window_size, predict_step, truncate)
self.decoder = Decoder(
# model,
d_model,
d_inner_hid,
num_head,
d_k,
d_v,
dropout,
enc_in,
covariate_size,
seq_num,
mask,
)
self.predictor = Predictor(d_model, enc_in)
elif decoder == "FC":
self.predictor = Predictor(4 * d_model, predict_step * enc_in)
def forward(self, x_enc, x_mark_enc, x_dec, x_mark_dec, pretrain):
"""
Return the hidden representations and predictions.
For a sequence (l_1, l_2, ..., l_N), we predict (l_2, ..., l_N, l_{N+1}).
Input: event_type: batch*seq_len;
event_time: batch*seq_len.
Output: enc_output: batch*seq_len*model_dim;
type_prediction: batch*seq_len*num_classes (not normalized);
time_prediction: batch*seq_len.
"""
if self.decoder_type == "attention":
enc_output = self.encoder(x_enc, x_mark_enc)
dec_enc = self.decoder(x_dec, x_mark_dec, enc_output)
if pretrain:
dec_enc = torch.cat([enc_output[:, : self.input_size], dec_enc], dim=1)
pred = self.predictor(dec_enc)
else:
pred = self.predictor(dec_enc)
elif self.decoder_type == "FC":
enc_output = self.encoder(x_enc, x_mark_enc)[:, -1, :]
pred = self.predictor(enc_output).view(
enc_output.size(0), self.predict_step, -1
)
return pred
@property
def _past_length(self) -> int:
return self.predict_step # + max(0,self.lags_seq)
@property
def _number_of_features(self) -> int:
return (
sum(self.embedding_dimension)
+ self.num_feat_dynamic_real
+ self.num_feat_static_real
+ 1 # the log(scale)
)
def get_lagged_subsequences(
self, sequence: torch.Tensor, subsequences_length: int, shift: int = 0
) -> torch.Tensor:
"""
Returns lagged subsequences of a given sequence.
Parameters
----------
sequence : Tensor
the sequence from which lagged subsequences should be extracted.
Shape: (N, T, C).
subsequences_length : int
length of the subsequences to be extracted.
shift: int
shift the lags by this amount back.
Returns
--------
lagged : Tensor
a tensor of shape (N, S, C, I), where S = subsequences_length and
I = len(indices), containing lagged subsequences. Specifically,
lagged[i, j, :, k] = sequence[i, -indices[k]-S+j, :].
"""
sequence_length = sequence.shape[1]
indices = [lag - shift for lag in self.lags_seq]
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}"
)
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)
def _check_shapes(
self,
prior_input: torch.Tensor,
inputs: torch.Tensor,
features: Optional[torch.Tensor],
) -> None:
assert len(prior_input.shape) == len(inputs.shape)
assert (
len(prior_input.shape) == 2 and self.input_size == 1
) or prior_input.shape[2] == self.input_size
assert (len(inputs.shape) == 2 and self.input_size == 1) or inputs.shape[
-1
] == self.input_size
assert (
features is None or features.shape[2] == self._number_of_features
), f"{features.shape[2]}, expected {self._number_of_features}"
def create_network_inputs(
self,
feat_static_cat: torch.Tensor,
feat_static_real: torch.Tensor,
past_time_feat: torch.Tensor,
past_target: torch.Tensor,
past_observed_values: torch.Tensor,
future_time_feat: Optional[torch.Tensor] = None,
future_target: Optional[torch.Tensor] = None,
):
# time feature
time_feat = (
torch.cat(
(
past_time_feat[:, self._past_length - self.context_length :, ...],
future_time_feat,
),
dim=1,
)
if future_target is not None
else past_time_feat[:, self._past_length - self.context_length :, ...]
)
# target
context = past_target[:, -self.context_length :]
observed_context = past_observed_values[:, -self.context_length :]
_, scale = self.scaler(context, observed_context)
inputs = (
torch.cat((past_target, future_target), dim=1) / scale
if future_target is not None
else past_target / scale
)
inputs_length = (
self._past_length + self.prediction_length
if future_target is not None
else self._past_length
)
assert inputs.shape[1] == inputs_length
subsequences_length = (
self.context_length + self.prediction_length
if future_target is not None
else self.context_length
)
# embeddings
embedded_cat = self.embedder(feat_static_cat)
static_feat = torch.cat(
(embedded_cat, feat_static_real, scale.log()),
dim=1,
)
expanded_static_feat = static_feat.unsqueeze(1).expand(
-1, time_feat.shape[1], -1
)
features = torch.cat((expanded_static_feat, time_feat), dim=-1)
# self._check_shapes(prior_input, inputs, features)
# sequence = torch.cat((prior_input, inputs), dim=1)
lagged_sequence = self.get_lagged_subsequences(
sequence=inputs,
subsequences_length=subsequences_length,
)
lags_shape = lagged_sequence.shape
reshaped_lagged_sequence = lagged_sequence.reshape(
lags_shape[0], lags_shape[1], -1
)
transformer_inputs = torch.cat((reshaped_lagged_sequence, features), dim=-1)
return transformer_inputs, scale, static_feat
def output_params(self, transformer_inputs):
enc_input = transformer_inputs[:, : self.context_length, ...]
dec_input = transformer_inputs[:, self.context_length :, ...]
enc_out = self.transformer.encoder(enc_input)
dec_output = self.transformer.decoder(
dec_input, enc_out, tgt_mask=self.tgt_mask
)
return self.param_proj(dec_output)
@torch.jit.ignore
def output_distribution(
self, params, scale=None, trailing_n=None
) -> torch.distributions.Distribution:
sliced_params = params
if trailing_n is not None:
sliced_params = [p[:, -trailing_n:] for p in params]
return self.distr_output.distribution(sliced_params, scale=scale)