TabPFNPrediction / TabPFN /encoders.py
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Upload encoders.py
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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, num_hyperparameters, em_size):
super().__init__()
self.em_size = em_size
self.embedding = nn.Linear(num_hyperparameters, self.em_size)
def forward(self, hyperparameters): # B x num_hps
return self.embedding(hyperparameters)
class StyleEmbEncoder(nn.Module):
def __init__(self, num_hyperparameters, em_size, num_embeddings=100):
super().__init__()
assert num_hyperparameters == 1
self.em_size = em_size
self.embedding = nn.Embedding(num_embeddings, self.em_size)
def forward(self, hyperparameters): # B x num_hps
return self.embedding(hyperparameters.squeeze(1))
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))
def get_normalized_encoder(encoder_creator, data_std):
return lambda in_dim, out_dim: nn.Sequential(Normalize(0., data_std), encoder_creator(in_dim, out_dim))
class ZNormalize(nn.Module):
def forward(self, x):
return (x-x.mean(-1,keepdim=True))/x.std(-1,keepdim=True)
class AppendEmbeddingEncoder(nn.Module):
def __init__(self, base_encoder, num_features, emsize):
super().__init__()
self.num_features = num_features
self.base_encoder = base_encoder
self.emb = nn.Parameter(torch.zeros(emsize))
def forward(self, x):
if (x[-1] == 1.).all():
append_embedding = True
else:
assert (x[-1] == 0.).all(), "You need to specify as last position whether to append embedding. " \
"If you don't want this behavior, please use the wrapped encoder instead."
append_embedding = False
x = x[:-1]
encoded_x = self.base_encoder(x)
if append_embedding:
encoded_x = torch.cat([encoded_x, self.emb[None, None, :].repeat(1, encoded_x.shape[1], 1)], 0)
return encoded_x
def get_append_embedding_encoder(encoder_creator):
return lambda num_features, emsize: AppendEmbeddingEncoder(encoder_creator(num_features, emsize), num_features, emsize)
class VariableNumFeaturesEncoder(nn.Module):
def __init__(self, base_encoder, num_features):
super().__init__()
self.base_encoder = base_encoder
self.num_features = num_features
def forward(self, x):
x = x * (self.num_features/x.shape[-1])
x = torch.cat((x, torch.zeros(*x.shape[:-1], self.num_features - x.shape[-1], device=x.device)), -1)
return self.base_encoder(x)
def get_variable_num_features_encoder(encoder_creator):
return lambda num_features, emsize: VariableNumFeaturesEncoder(encoder_creator(num_features, emsize), num_features)
class NoMeanEncoder(nn.Module):
"""
This can be useful for any prior that is translation invariant in x or y.
A standard GP for example is translation invariant in x.
That is, GP(x_test+const,x_train+const,y_train) = GP(x_test,x_train,y_train).
"""
def __init__(self, base_encoder):
super().__init__()
self.base_encoder = base_encoder
def forward(self, x):
return self.base_encoder(x - x.mean(0, keepdim=True))
def get_no_mean_encoder(encoder_creator):
return lambda num_features, emsize: NoMeanEncoder(encoder_creator(num_features, emsize))
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, replace_nan_by_zero=False):
super().__init__(num_features, emsize)
self.num_features = num_features
self.emsize = emsize
self.replace_nan_by_zero = replace_nan_by_zero
def forward(self, x):
if self.replace_nan_by_zero:
x = torch.nan_to_num(x, nan=0.0)
return super().forward(x)
def __setstate__(self, state):
super().__setstate__(state)
self.__dict__.setdefault('replace_nan_by_zero', True)
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)