Samuel Mueller
init
e487255
import math
import torch
import torch.nn as nn
from utils import normalize_data
import torch.nn.functional as F
from torch.nn import TransformerEncoder, TransformerEncoderLayer
class StyleEncoder(nn.Module):
def __init__(self, em_size, hyperparameter_definitions):
super().__init__()
# self.embeddings = {}
self.em_size = em_size
# self.hyperparameter_definitions = {}
# for hp in hyperparameter_definitions:
# self.embeddings[hp] = nn.Linear(1, self.em_size)
# self.embeddings = nn.ModuleDict(self.embeddings)
self.embedding = nn.Linear(hyperparameter_definitions.shape[0], self.em_size)
def forward(self, hyperparameters): # T x B x num_features
# Make faster by using matrices
# sampled_embeddings = [torch.stack([
# self.embeddings[hp](torch.tensor([batch[hp]], device=self.embeddings[hp].weight.device, dtype=torch.float))
# for hp in batch
# ], -1).sum(-1) for batch in hyperparameters]
# return torch.stack(sampled_embeddings, 0)
return self.embedding(hyperparameters)
class _PositionalEncoding(nn.Module):
def __init__(self, d_model, dropout=0.):
super().__init__()
self.dropout = nn.Dropout(p=dropout)
self.d_model = d_model
self.device_test_tensor = nn.Parameter(torch.tensor(1.))
def forward(self, x):# T x B x num_features
assert self.d_model % x.shape[-1]*2 == 0
d_per_feature = self.d_model // x.shape[-1]
pe = torch.zeros(*x.shape, d_per_feature, device=self.device_test_tensor.device)
#position = torch.arange(0, max_len, dtype=torch.float).unsqueeze(1)
interval_size = 10
div_term = (1./interval_size) * 2*math.pi*torch.exp(torch.arange(0, d_per_feature, 2, device=self.device_test_tensor.device).float()*math.log(math.sqrt(2)))
#print(div_term/2/math.pi)
pe[..., 0::2] = torch.sin(x.unsqueeze(-1) * div_term)
pe[..., 1::2] = torch.cos(x.unsqueeze(-1) * div_term)
return self.dropout(pe).view(x.shape[0],x.shape[1],self.d_model)
Positional = lambda _, emsize: _PositionalEncoding(d_model=emsize)
class EmbeddingEncoder(nn.Module):
def __init__(self, num_features, em_size, num_embs=100):
super().__init__()
self.num_embs = num_embs
self.embeddings = nn.Embedding(num_embs * num_features, em_size, max_norm=True)
self.init_weights(.1)
self.min_max = (-2,+2)
@property
def width(self):
return self.min_max[1] - self.min_max[0]
def init_weights(self, initrange):
self.embeddings.weight.data.uniform_(-initrange, initrange)
def discretize(self, x):
split_size = self.width / self.num_embs
return (x - self.min_max[0] // split_size).int().clamp(0, self.num_embs - 1)
def forward(self, x): # T x B x num_features
x_idxs = self.discretize(x)
x_idxs += torch.arange(x.shape[-1], device=x.device).view(1, 1, -1) * self.num_embs
# print(x_idxs,self.embeddings.weight.shape)
return self.embeddings(x_idxs).mean(-2)
class Normalize(nn.Module):
def __init__(self, mean, std):
super().__init__()
self.mean = mean
self.std = std
def forward(self, x):
return (x-self.mean)/self.std
def get_normalized_uniform_encoder(encoder_creator):
"""
This can be used to wrap an encoder that is fed uniform samples in [0,1] and normalizes these to 0 mean and 1 std.
For example, it can be used as `encoder_creator = get_normalized_uniform_encoder(encoders.Linear)`, now this can
be initialized with `encoder_creator(feature_dim, in_dim)`.
:param encoder:
:return:
"""
return lambda in_dim, out_dim: nn.Sequential(Normalize(.5, math.sqrt(1/12)), encoder_creator(in_dim, out_dim))
Linear = nn.Linear
MLP = lambda num_features, emsize: nn.Sequential(nn.Linear(num_features+1,emsize*2),
nn.ReLU(),
nn.Linear(emsize*2,emsize))
class NanHandlingEncoder(nn.Module):
def __init__(self, num_features, emsize, keep_nans=True):
super().__init__()
self.num_features = 2 * num_features if keep_nans else num_features
self.emsize = emsize
self.keep_nans = keep_nans
self.layer = nn.Linear(self.num_features, self.emsize)
def forward(self, x):
if self.keep_nans:
x = torch.cat([torch.nan_to_num(x, nan=0.0), normalize_data(torch.isnan(x) * -1
+ torch.logical_and(torch.isinf(x), torch.sign(x) == 1) * 1
+ torch.logical_and(torch.isinf(x), torch.sign(x) == -1) * 2
)], -1)
else:
x = torch.nan_to_num(x, nan=0.0)
return self.layer(x)
class Linear(nn.Linear):
def __init__(self, num_features, emsize):
super().__init__(num_features, emsize)
self.num_features = num_features
self.emsize = emsize
def forward(self, x):
x = torch.nan_to_num(x, nan=0.0)
return super().forward(x)
class SequenceSpanningEncoder(nn.Module):
# Regular Encoder transforms Seq_len, B, S -> Seq_len, B, E attending only to last dimension
# This Encoder accesses the Seq_Len dimension additionally
# Why would we want this? We can learn normalization and embedding of features
# , this might be more important for e.g. categorical, ordinal feats, nan detection
# However maybe this can be easily learned through transformer as well?
# A problem is to make this work across any sequence length and be independent of ordering
# We could use average and maximum pooling and use those with a linear layer
# Another idea !! Similar to this we would like to encode features so that their number is variable
# We would like to embed features, also using knowledge of the features in the entire sequence
# We could use convolution or another transformer
# Convolution:
# Transformer/Conv across sequence dimension that encodes and normalizes features
# -> Transformer across feature dimension that encodes features to a constant size
# Conv with flexible features but no sequence info: S,B,F -(reshape)-> S*B,1,F
# -(Conv1d)-> S*B,N,F -(AvgPool,MaxPool)-> S*B,N,1 -> S,B,N
# This probably won't work since it's missing a way to recognize which feature is encoded
# Transformer with flexible features: S,B,F -> F,B*S,1 -> F2,B*S,1 -> S,B,F2
def __init__(self, num_features, em_size):
super().__init__()
raise NotImplementedError()
# Seq_len, B, S -> Seq_len, B, E
#
self.convs = torch.nn.ModuleList([nn.Conv1d(64 if i else 1, 64, 3) for i in range(5)])
# self.linear = nn.Linear(64, emsize)
class TransformerBasedFeatureEncoder(nn.Module):
def __init__(self, num_features, emsize):
super().__init__()
hidden_emsize = emsize
encoder = Linear(1, hidden_emsize)
n_out = emsize
nhid = 2*emsize
dropout =0.0
nhead=4
nlayers=4
model = nn.Transformer(nhead=nhead, num_encoder_layers=4, num_decoder_layers=4, d_model=1)
def forward(self, *input):
# S,B,F -> F,S*B,1 -> F2,S*B,1 -> S,B,F2
input = input.transpose()
self.model(input)
class Conv(nn.Module):
def __init__(self, input_size, emsize):
super().__init__()
self.convs = torch.nn.ModuleList([nn.Conv2d(64 if i else 1, 64, 3) for i in range(5)])
self.linear = nn.Linear(64,emsize)
def forward(self, x):
size = math.isqrt(x.shape[-1])
assert size*size == x.shape[-1]
x = x.reshape(*x.shape[:-1], 1, size, size)
for conv in self.convs:
if x.shape[-1] < 4:
break
x = conv(x)
x.relu_()
x = nn.AdaptiveAvgPool2d((1,1))(x).squeeze(-1).squeeze(-1)
return self.linear(x)
class CanEmb(nn.Embedding):
def __init__(self, num_features, num_embeddings: int, embedding_dim: int, *args, **kwargs):
assert embedding_dim % num_features == 0
embedding_dim = embedding_dim // num_features
super().__init__(num_embeddings, embedding_dim, *args, **kwargs)
def forward(self, x):
lx = x.long()
assert (lx == x).all(), "CanEmb only works with tensors of whole numbers"
x = super().forward(lx)
return x.view(*x.shape[:-2], -1)
def get_Canonical(num_classes):
return lambda num_features, emsize: CanEmb(num_features, num_classes, emsize)
def get_Embedding(num_embs_per_feature=100):
return lambda num_features, emsize: EmbeddingEncoder(num_features, emsize, num_embs=num_embs_per_feature)