elephantmipt
commited on
Upload BatchTopKSAE
Browse files- config.json +4 -0
- config.py +177 -0
- sae.py +390 -0
config.json
CHANGED
@@ -3,6 +3,10 @@
|
|
3 |
"architectures": [
|
4 |
"BatchTopKSAE"
|
5 |
],
|
|
|
|
|
|
|
|
|
6 |
"aux_penalty": 0.03125,
|
7 |
"bandwidth": 0.001,
|
8 |
"dict_size": 128,
|
|
|
3 |
"architectures": [
|
4 |
"BatchTopKSAE"
|
5 |
],
|
6 |
+
"auto_map": {
|
7 |
+
"AutoConfig": "config.SAEConfig",
|
8 |
+
"AutoModel": "sae.BatchTopKSAE"
|
9 |
+
},
|
10 |
"aux_penalty": 0.03125,
|
11 |
"bandwidth": 0.001,
|
12 |
"dict_size": 128,
|
config.py
ADDED
@@ -0,0 +1,177 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
from dataclasses import dataclass, field
|
2 |
+
from typing import Optional, Literal
|
3 |
+
import torch
|
4 |
+
import pyrallis
|
5 |
+
from transformers import PretrainedConfig
|
6 |
+
from typing import Optional
|
7 |
+
from dataclasses import asdict
|
8 |
+
|
9 |
+
|
10 |
+
@dataclass
|
11 |
+
class TrainingConfig:
|
12 |
+
# Model settings
|
13 |
+
model_name: str = "unsloth/Meta-Llama-3.1-8B"
|
14 |
+
layer: int = 12
|
15 |
+
hook_point: str = "resid_mid"
|
16 |
+
act_size: Optional[int] = None # Will be set after model initialization
|
17 |
+
|
18 |
+
# SAE settings
|
19 |
+
sae_type: str = "batchtopk"
|
20 |
+
dict_size: int = 2**15
|
21 |
+
aux_penalty: float = 1/32
|
22 |
+
input_unit_norm: bool = True
|
23 |
+
|
24 |
+
# TopK specific settings
|
25 |
+
top_k: int = 50
|
26 |
+
top_k_warmup_steps_fraction: float = 0.1
|
27 |
+
start_top_k: int = 4096
|
28 |
+
top_k_aux: int = 512
|
29 |
+
|
30 |
+
n_batches_to_dead: int = 10
|
31 |
+
|
32 |
+
# Training settings
|
33 |
+
lr: float = 3e-4
|
34 |
+
bandwidth: float = 0.001
|
35 |
+
l1_coeff: float = 0.0018
|
36 |
+
num_tokens: int = int(1e9)
|
37 |
+
seq_len: int = 1024
|
38 |
+
model_batch_size: int = 16
|
39 |
+
num_batches_in_buffer: int = 5
|
40 |
+
max_grad_norm: float = 1.0
|
41 |
+
batch_size: int = 8192
|
42 |
+
|
43 |
+
# scheduler
|
44 |
+
warmup_fraction: float = 0.1
|
45 |
+
scheduler_type: str = 'linear'
|
46 |
+
|
47 |
+
# Hardware settings
|
48 |
+
device: str = "cuda"
|
49 |
+
dtype: torch.dtype = field(default=torch.float32)
|
50 |
+
sae_dtype: torch.dtype = field(default=torch.float32)
|
51 |
+
|
52 |
+
# Dataset settings
|
53 |
+
dataset_path: str = "cerebras/SlimPajama-627B"
|
54 |
+
|
55 |
+
# Logging settings
|
56 |
+
wandb_project: str = "turbo-llama-lens"
|
57 |
+
|
58 |
+
performance_log_steps: int = 100
|
59 |
+
save_checkpoint_steps: int = 10_000
|
60 |
+
def __post_init__(self):
|
61 |
+
if self.device == "cuda" and not torch.cuda.is_available():
|
62 |
+
print("CUDA not available, falling back to CPU")
|
63 |
+
self.device = "cpu"
|
64 |
+
|
65 |
+
# Convert string dtype to torch.dtype if needed
|
66 |
+
if isinstance(self.dtype, str):
|
67 |
+
self.dtype = getattr(torch, self.dtype)
|
68 |
+
|
69 |
+
|
70 |
+
class SAEConfig(PretrainedConfig):
|
71 |
+
model_type = "sae"
|
72 |
+
|
73 |
+
def __init__(
|
74 |
+
self,
|
75 |
+
# SAE architecture
|
76 |
+
act_size: int = None,
|
77 |
+
dict_size: int = 2**15,
|
78 |
+
sae_type: str = "batchtopk",
|
79 |
+
input_unit_norm: bool = True,
|
80 |
+
|
81 |
+
# TopK specific settings
|
82 |
+
top_k: int = 50,
|
83 |
+
top_k_aux: int = 512,
|
84 |
+
n_batches_to_dead: int = 10,
|
85 |
+
|
86 |
+
# Training hyperparameters
|
87 |
+
aux_penalty: float = 1/32,
|
88 |
+
l1_coeff: float = 0.0018,
|
89 |
+
bandwidth: float = 0.001,
|
90 |
+
|
91 |
+
# Hardware settings
|
92 |
+
dtype: str = "float32",
|
93 |
+
sae_dtype: str = "float32",
|
94 |
+
|
95 |
+
# Optional parent model info
|
96 |
+
parent_model_name: Optional[str] = None,
|
97 |
+
parent_layer: Optional[int] = None,
|
98 |
+
parent_hook_point: Optional[str] = None,
|
99 |
+
|
100 |
+
**kwargs
|
101 |
+
):
|
102 |
+
super().__init__(**kwargs)
|
103 |
+
self.act_size = act_size
|
104 |
+
self.dict_size = dict_size
|
105 |
+
self.sae_type = sae_type
|
106 |
+
self.input_unit_norm = input_unit_norm
|
107 |
+
|
108 |
+
self.top_k = top_k
|
109 |
+
self.top_k_aux = top_k_aux
|
110 |
+
self.n_batches_to_dead = n_batches_to_dead
|
111 |
+
|
112 |
+
self.aux_penalty = aux_penalty
|
113 |
+
self.l1_coeff = l1_coeff
|
114 |
+
self.bandwidth = bandwidth
|
115 |
+
|
116 |
+
self.dtype = dtype
|
117 |
+
self.sae_dtype = sae_dtype
|
118 |
+
|
119 |
+
self.parent_model_name = parent_model_name
|
120 |
+
self.parent_layer = parent_layer
|
121 |
+
self.parent_hook_point = parent_hook_point
|
122 |
+
|
123 |
+
def get_torch_dtype(self, dtype_str: str) -> torch.dtype:
|
124 |
+
dtype_map = {
|
125 |
+
"float32": torch.float32,
|
126 |
+
"float16": torch.float16,
|
127 |
+
"bfloat16": torch.bfloat16,
|
128 |
+
}
|
129 |
+
return dtype_map.get(dtype_str, torch.float32)
|
130 |
+
|
131 |
+
@classmethod
|
132 |
+
def from_training_config(cls, cfg: TrainingConfig):
|
133 |
+
"""Convert TrainingConfig to SAEConfig"""
|
134 |
+
return cls(
|
135 |
+
act_size=cfg.act_size,
|
136 |
+
dict_size=cfg.dict_size,
|
137 |
+
sae_type=cfg.sae_type,
|
138 |
+
input_unit_norm=cfg.input_unit_norm,
|
139 |
+
top_k=cfg.top_k,
|
140 |
+
top_k_aux=cfg.top_k_aux,
|
141 |
+
n_batches_to_dead=cfg.n_batches_to_dead,
|
142 |
+
aux_penalty=cfg.aux_penalty,
|
143 |
+
l1_coeff=cfg.l1_coeff,
|
144 |
+
bandwidth=cfg.bandwidth,
|
145 |
+
dtype=str(cfg.dtype).split('.')[-1],
|
146 |
+
sae_dtype=str(cfg.sae_dtype).split('.')[-1],
|
147 |
+
parent_model_name=cfg.model_name,
|
148 |
+
parent_layer=cfg.layer,
|
149 |
+
parent_hook_point=cfg.hook_point,
|
150 |
+
)
|
151 |
+
|
152 |
+
def to_training_config(self) -> TrainingConfig:
|
153 |
+
"""Convert SAEConfig back to TrainingConfig"""
|
154 |
+
config_dict = asdict(self)
|
155 |
+
config_dict['dtype'] = self.get_torch_dtype(self.dtype)
|
156 |
+
config_dict['sae_dtype'] = self.get_torch_dtype(self.sae_dtype)
|
157 |
+
config_dict['model_name'] = self.parent_model_name
|
158 |
+
config_dict['layer'] = self.parent_layer
|
159 |
+
config_dict['hook_point'] = self.parent_hook_point
|
160 |
+
return TrainingConfig(**config_dict)
|
161 |
+
|
162 |
+
|
163 |
+
@pyrallis.wrap()
|
164 |
+
def get_config() -> TrainingConfig:
|
165 |
+
return TrainingConfig()
|
166 |
+
|
167 |
+
|
168 |
+
# For backward compatibility
|
169 |
+
def get_default_cfg() -> TrainingConfig:
|
170 |
+
return get_config()
|
171 |
+
|
172 |
+
|
173 |
+
def post_init_cfg(cfg: TrainingConfig) -> TrainingConfig:
|
174 |
+
"""
|
175 |
+
Any additional configuration setup that needs to happen after model initialization
|
176 |
+
"""
|
177 |
+
return cfg
|
sae.py
ADDED
@@ -0,0 +1,390 @@
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
+
from transformers import PreTrainedModel
|
2 |
+
from typing import Optional, Dict, Union
|
3 |
+
import torch
|
4 |
+
import torch.nn as nn
|
5 |
+
import torch.nn.functional as F
|
6 |
+
import torch.autograd as autograd
|
7 |
+
from copy import deepcopy
|
8 |
+
from safetensors.torch import save_file, load_file
|
9 |
+
from sae.modeling.config import SAEConfig
|
10 |
+
import os
|
11 |
+
|
12 |
+
|
13 |
+
class BaseSAE(PreTrainedModel):
|
14 |
+
"""Base class for autoencoder models."""
|
15 |
+
config_class = SAEConfig
|
16 |
+
base_model_prefix = "sae"
|
17 |
+
|
18 |
+
def __init__(self, config: SAEConfig):
|
19 |
+
super().__init__(config)
|
20 |
+
print(config)
|
21 |
+
self.config = config
|
22 |
+
torch.manual_seed(42)
|
23 |
+
|
24 |
+
self.b_dec = nn.Parameter(torch.zeros(self.config.act_size))
|
25 |
+
self.b_enc = nn.Parameter(torch.zeros(self.config.dict_size))
|
26 |
+
self.W_enc = nn.Parameter(
|
27 |
+
torch.nn.init.kaiming_uniform_(
|
28 |
+
torch.empty(self.config.act_size, self.config.dict_size)
|
29 |
+
)
|
30 |
+
)
|
31 |
+
self.W_dec = nn.Parameter(
|
32 |
+
torch.nn.init.kaiming_uniform_(
|
33 |
+
torch.empty(self.config.dict_size, self.config.act_size)
|
34 |
+
)
|
35 |
+
)
|
36 |
+
self.W_dec.data[:] = self.W_enc.t().data
|
37 |
+
self.W_dec.data[:] = self.W_dec / self.W_dec.norm(dim=-1, keepdim=True)
|
38 |
+
self.num_batches_not_active = torch.zeros((self.config.dict_size,))
|
39 |
+
|
40 |
+
self.to(self.config.get_torch_dtype(self.config.dtype))
|
41 |
+
|
42 |
+
def preprocess_input(self, x):
|
43 |
+
x = x.to(self.config.get_torch_dtype(self.config.sae_dtype))
|
44 |
+
if self.config.input_unit_norm:
|
45 |
+
x_mean = x.mean(dim=-1, keepdim=True)
|
46 |
+
x = x - x_mean
|
47 |
+
x_std = x.std(dim=-1, keepdim=True)
|
48 |
+
x = x / (x_std + 1e-5)
|
49 |
+
return x, x_mean, x_std
|
50 |
+
else:
|
51 |
+
return x, None, None
|
52 |
+
|
53 |
+
def postprocess_output(self, x_reconstruct, x_mean, x_std):
|
54 |
+
if self.config.input_unit_norm:
|
55 |
+
x_reconstruct = x_reconstruct * x_std + x_mean
|
56 |
+
return x_reconstruct
|
57 |
+
|
58 |
+
@torch.no_grad()
|
59 |
+
def make_decoder_weights_and_grad_unit_norm(self):
|
60 |
+
W_dec_normed = self.W_dec / self.W_dec.norm(dim=-1, keepdim=True)
|
61 |
+
W_dec_grad_proj = (self.W_dec.grad * W_dec_normed).sum(
|
62 |
+
-1, keepdim=True
|
63 |
+
) * W_dec_normed
|
64 |
+
self.W_dec.grad -= W_dec_grad_proj
|
65 |
+
self.W_dec.data = W_dec_normed
|
66 |
+
|
67 |
+
def update_inactive_features(self, acts):
|
68 |
+
self.num_batches_not_active += (acts.sum(0) == 0).float()
|
69 |
+
self.num_batches_not_active[acts.sum(0) > 0] = 0
|
70 |
+
|
71 |
+
# @classmethod
|
72 |
+
# def from_pretrained(
|
73 |
+
# cls,
|
74 |
+
# pretrained_model_name_or_path: Optional[Union[str, os.PathLike]],
|
75 |
+
# *model_args,
|
76 |
+
# **kwargs
|
77 |
+
# ) -> "BaseSAE":
|
78 |
+
# config = kwargs.pop("config", None)
|
79 |
+
# if config is None:
|
80 |
+
# config = SAEConfig.from_pretrained(pretrained_model_name_or_path, **kwargs)
|
81 |
+
|
82 |
+
# model = cls(config)
|
83 |
+
# model.load_state_dict(
|
84 |
+
# load_file(os.path.join(pretrained_model_name_or_path, "model.safetensors"))
|
85 |
+
# )
|
86 |
+
# return model
|
87 |
+
|
88 |
+
# def save_pretrained(
|
89 |
+
# self,
|
90 |
+
# save_directory: Union[str, os.PathLike],
|
91 |
+
# **kwargs
|
92 |
+
# ):
|
93 |
+
# os.makedirs(save_directory, exist_ok=True)
|
94 |
+
|
95 |
+
# # Save the config
|
96 |
+
# self.config.save_pretrained(save_directory)
|
97 |
+
|
98 |
+
# # Save the model weights
|
99 |
+
# save_file(
|
100 |
+
# self.state_dict(),
|
101 |
+
# os.path.join(save_directory, "model.safetensors")
|
102 |
+
# )
|
103 |
+
|
104 |
+
|
105 |
+
class BatchTopKSAE(BaseSAE):
|
106 |
+
def forward(self, x):
|
107 |
+
x, x_mean, x_std = self.preprocess_input(x)
|
108 |
+
|
109 |
+
x_cent = x - self.b_dec
|
110 |
+
acts = F.relu(x_cent @ self.W_enc)
|
111 |
+
acts_topk = torch.topk(acts.flatten(), self.config.top_k * x.shape[0], dim=-1)
|
112 |
+
acts_topk = (
|
113 |
+
torch.zeros_like(acts.flatten())
|
114 |
+
.scatter(-1, acts_topk.indices, acts_topk.values)
|
115 |
+
.reshape(acts.shape)
|
116 |
+
)
|
117 |
+
x_reconstruct = acts_topk @ self.W_dec + self.b_dec
|
118 |
+
|
119 |
+
self.update_inactive_features(acts_topk)
|
120 |
+
output = self.get_loss_dict(x, x_reconstruct, acts, acts_topk, x_mean, x_std)
|
121 |
+
return output
|
122 |
+
|
123 |
+
def get_loss_dict(self, x, x_reconstruct, acts, acts_topk, x_mean, x_std):
|
124 |
+
l2_loss = (x_reconstruct.float() - x.float()).pow(2).mean()
|
125 |
+
l1_norm = acts_topk.float().abs().sum(-1).mean()
|
126 |
+
l1_loss = self.config.l1_coeff * l1_norm
|
127 |
+
l0_norm = (acts_topk > 0).float().sum(-1).mean()
|
128 |
+
aux_loss = self.get_auxiliary_loss(x, x_reconstruct, acts)
|
129 |
+
loss = l2_loss + aux_loss
|
130 |
+
num_dead_features = (
|
131 |
+
self.num_batches_not_active > self.config.n_batches_to_dead
|
132 |
+
).sum()
|
133 |
+
sae_out = self.postprocess_output(x_reconstruct, x_mean, x_std)
|
134 |
+
per_token_l2_loss_A = (x_reconstruct.float() - x.float()).pow(2).sum(-1).squeeze()
|
135 |
+
total_variance_A = (x.float() - x.float().mean(0)).pow(2).sum(-1).squeeze()
|
136 |
+
explained_variance = (1 - per_token_l2_loss_A / total_variance_A).mean()
|
137 |
+
output = {
|
138 |
+
"sae_out": sae_out,
|
139 |
+
"feature_acts": acts_topk,
|
140 |
+
"num_dead_features": num_dead_features,
|
141 |
+
"loss": loss,
|
142 |
+
"l1_loss": l1_loss,
|
143 |
+
"l2_loss": l2_loss,
|
144 |
+
"l0_norm": l0_norm,
|
145 |
+
"l1_norm": l1_norm,
|
146 |
+
"aux_loss": aux_loss,
|
147 |
+
"explained_variance": explained_variance,
|
148 |
+
"top_k": self.config.top_k
|
149 |
+
}
|
150 |
+
return output
|
151 |
+
|
152 |
+
def get_auxiliary_loss(self, x, x_reconstruct, acts):
|
153 |
+
dead_features = self.num_batches_not_active >= self.config.n_batches_to_dead
|
154 |
+
if dead_features.sum() > 0:
|
155 |
+
residual = x.float() - x_reconstruct.float()
|
156 |
+
acts_topk_aux = torch.topk(
|
157 |
+
acts[:, dead_features],
|
158 |
+
min(self.config.top_k_aux, dead_features.sum()),
|
159 |
+
dim=-1,
|
160 |
+
)
|
161 |
+
acts_aux = torch.zeros_like(acts[:, dead_features]).scatter(
|
162 |
+
-1, acts_topk_aux.indices, acts_topk_aux.values
|
163 |
+
)
|
164 |
+
x_reconstruct_aux = acts_aux @ self.W_dec[dead_features]
|
165 |
+
l2_loss_aux = (
|
166 |
+
self.config.aux_penalty
|
167 |
+
* (x_reconstruct_aux.float() - residual.float()).pow(2).mean()
|
168 |
+
)
|
169 |
+
return l2_loss_aux
|
170 |
+
else:
|
171 |
+
return torch.tensor(0, dtype=x.dtype, device=x.device)
|
172 |
+
|
173 |
+
|
174 |
+
class TopKSAE(BaseSAE):
|
175 |
+
def forward(self, x):
|
176 |
+
x, x_mean, x_std = self.preprocess_input(x)
|
177 |
+
|
178 |
+
x_cent = x - self.b_dec
|
179 |
+
acts = F.relu(x_cent @ self.W_enc)
|
180 |
+
acts_topk = torch.topk(acts, self.config.top_k, dim=-1)
|
181 |
+
acts_topk = torch.zeros_like(acts).scatter(
|
182 |
+
-1, acts_topk.indices, acts_topk.values
|
183 |
+
)
|
184 |
+
x_reconstruct = acts_topk @ self.W_dec + self.b_dec
|
185 |
+
|
186 |
+
self.update_inactive_features(acts_topk)
|
187 |
+
output = self.get_loss_dict(x, x_reconstruct, acts, acts_topk, x_mean, x_std)
|
188 |
+
return output
|
189 |
+
|
190 |
+
def get_loss_dict(self, x, x_reconstruct, acts, acts_topk, x_mean, x_std):
|
191 |
+
l2_loss = (x_reconstruct.float() - x.float()).pow(2).mean()
|
192 |
+
l1_norm = acts_topk.float().abs().sum(-1).mean()
|
193 |
+
l1_loss = self.config.l1_coeff * l1_norm
|
194 |
+
l0_norm = (acts_topk > 0).float().sum(-1).mean()
|
195 |
+
aux_loss = self.get_auxiliary_loss(x, x_reconstruct, acts)
|
196 |
+
loss = l2_loss + l1_loss + aux_loss
|
197 |
+
num_dead_features = (
|
198 |
+
self.num_batches_not_active > self.config.n_batches_to_dead
|
199 |
+
).sum()
|
200 |
+
sae_out = self.postprocess_output(x_reconstruct, x_mean, x_std)
|
201 |
+
per_token_l2_loss_A = (x_reconstruct.float() - x.float()).pow(2).sum(-1).squeeze()
|
202 |
+
total_variance_A = (x.float() - x.float().mean(0)).pow(2).sum(-1).squeeze()
|
203 |
+
explained_variance = (1 - per_token_l2_loss_A / total_variance_A).mean()
|
204 |
+
output = {
|
205 |
+
"sae_out": sae_out,
|
206 |
+
"feature_acts": acts_topk,
|
207 |
+
"num_dead_features": num_dead_features,
|
208 |
+
"loss": loss,
|
209 |
+
"l1_loss": l1_loss,
|
210 |
+
"l2_loss": l2_loss,
|
211 |
+
"l0_norm": l0_norm,
|
212 |
+
"l1_norm": l1_norm,
|
213 |
+
"explained_variance": explained_variance,
|
214 |
+
"aux_loss": aux_loss,
|
215 |
+
}
|
216 |
+
return output
|
217 |
+
|
218 |
+
def get_auxiliary_loss(self, x, x_reconstruct, acts):
|
219 |
+
dead_features = self.num_batches_not_active >= self.config.n_batches_to_dead
|
220 |
+
if dead_features.sum() > 0:
|
221 |
+
residual = x.float() - x_reconstruct.float()
|
222 |
+
acts_topk_aux = torch.topk(
|
223 |
+
acts[:, dead_features],
|
224 |
+
min(self.config.top_k_aux, dead_features.sum()),
|
225 |
+
dim=-1,
|
226 |
+
)
|
227 |
+
acts_aux = torch.zeros_like(acts[:, dead_features]).scatter(
|
228 |
+
-1, acts_topk_aux.indices, acts_topk_aux.values
|
229 |
+
)
|
230 |
+
x_reconstruct_aux = acts_aux @ self.W_dec[dead_features]
|
231 |
+
l2_loss_aux = (
|
232 |
+
self.config.aux_penalty
|
233 |
+
* (x_reconstruct_aux.float() - residual.float()).pow(2).mean()
|
234 |
+
)
|
235 |
+
return l2_loss_aux
|
236 |
+
else:
|
237 |
+
return torch.tensor(0, dtype=x.dtype, device=x.device)
|
238 |
+
|
239 |
+
|
240 |
+
class VanillaSAE(BaseSAE):
|
241 |
+
def forward(self, x):
|
242 |
+
x, x_mean, x_std = self.preprocess_input(x)
|
243 |
+
x_cent = x - self.b_dec
|
244 |
+
acts = F.relu(x_cent @ self.W_enc + self.b_enc)
|
245 |
+
x_reconstruct = acts @ self.W_dec + self.b_dec
|
246 |
+
self.update_inactive_features(acts)
|
247 |
+
output = self.get_loss_dict(x, x_reconstruct, acts, x_mean, x_std)
|
248 |
+
return output
|
249 |
+
|
250 |
+
def get_loss_dict(self, x, x_reconstruct, acts, x_mean, x_std):
|
251 |
+
l2_loss = (x_reconstruct.float() - x.float()).pow(2).mean()
|
252 |
+
l1_norm = acts.float().abs().sum(-1).mean()
|
253 |
+
l1_loss = self.config.l1_coeff * l1_norm
|
254 |
+
l0_norm = (acts > 0).float().sum(-1).mean()
|
255 |
+
loss = l2_loss + l1_loss
|
256 |
+
num_dead_features = (
|
257 |
+
self.num_batches_not_active > self.config.n_batches_to_dead
|
258 |
+
).sum()
|
259 |
+
|
260 |
+
sae_out = self.postprocess_output(x_reconstruct, x_mean, x_std)
|
261 |
+
per_token_l2_loss_A = (x_reconstruct.float() - x.float()).pow(2).sum(-1).squeeze()
|
262 |
+
total_variance_A = (x.float() - x.float().mean(0)).pow(2).sum(-1).squeeze()
|
263 |
+
explained_variance = (1 - per_token_l2_loss_A / total_variance_A).mean()
|
264 |
+
output = {
|
265 |
+
"sae_out": sae_out,
|
266 |
+
"feature_acts": acts,
|
267 |
+
"num_dead_features": num_dead_features,
|
268 |
+
"loss": loss,
|
269 |
+
"l1_loss": l1_loss,
|
270 |
+
"l2_loss": l2_loss,
|
271 |
+
"l0_norm": l0_norm,
|
272 |
+
"l1_norm": l1_norm,
|
273 |
+
"explained_variance": explained_variance,
|
274 |
+
}
|
275 |
+
return output
|
276 |
+
|
277 |
+
|
278 |
+
import torch
|
279 |
+
import torch.nn as nn
|
280 |
+
|
281 |
+
class RectangleFunction(autograd.Function):
|
282 |
+
@staticmethod
|
283 |
+
def forward(ctx, x):
|
284 |
+
ctx.save_for_backward(x)
|
285 |
+
return ((x > -0.5) & (x < 0.5)).float()
|
286 |
+
|
287 |
+
@staticmethod
|
288 |
+
def backward(ctx, grad_output):
|
289 |
+
(x,) = ctx.saved_tensors
|
290 |
+
grad_input = grad_output.clone()
|
291 |
+
grad_input[(x <= -0.5) | (x >= 0.5)] = 0
|
292 |
+
return grad_input
|
293 |
+
|
294 |
+
class JumpReLUFunction(autograd.Function):
|
295 |
+
@staticmethod
|
296 |
+
def forward(ctx, x, log_threshold, bandwidth):
|
297 |
+
ctx.save_for_backward(x, log_threshold, torch.tensor(bandwidth))
|
298 |
+
threshold = torch.exp(log_threshold)
|
299 |
+
return x * (x > threshold).float()
|
300 |
+
|
301 |
+
@staticmethod
|
302 |
+
def backward(ctx, grad_output):
|
303 |
+
x, log_threshold, bandwidth_tensor = ctx.saved_tensors
|
304 |
+
bandwidth = bandwidth_tensor.item()
|
305 |
+
threshold = torch.exp(log_threshold)
|
306 |
+
x_grad = (x > threshold).float() * grad_output
|
307 |
+
threshold_grad = (
|
308 |
+
-(threshold / bandwidth)
|
309 |
+
* RectangleFunction.apply((x - threshold) / bandwidth)
|
310 |
+
* grad_output
|
311 |
+
)
|
312 |
+
return x_grad, threshold_grad, None # None for bandwidth
|
313 |
+
|
314 |
+
class JumpReLU(nn.Module):
|
315 |
+
def __init__(self, feature_size, bandwidth, device='cpu'):
|
316 |
+
super(JumpReLU, self).__init__()
|
317 |
+
self.log_threshold = nn.Parameter(torch.zeros(feature_size, device=device))
|
318 |
+
self.bandwidth = bandwidth
|
319 |
+
|
320 |
+
def forward(self, x):
|
321 |
+
return JumpReLUFunction.apply(x, self.log_threshold, self.bandwidth)
|
322 |
+
|
323 |
+
class StepFunction(autograd.Function):
|
324 |
+
@staticmethod
|
325 |
+
def forward(ctx, x, log_threshold, bandwidth):
|
326 |
+
ctx.save_for_backward(x, log_threshold, torch.tensor(bandwidth))
|
327 |
+
threshold = torch.exp(log_threshold)
|
328 |
+
return (x > threshold).float()
|
329 |
+
|
330 |
+
@staticmethod
|
331 |
+
def backward(ctx, grad_output):
|
332 |
+
x, log_threshold, bandwidth_tensor = ctx.saved_tensors
|
333 |
+
bandwidth = bandwidth_tensor.item()
|
334 |
+
threshold = torch.exp(log_threshold)
|
335 |
+
x_grad = torch.zeros_like(x)
|
336 |
+
threshold_grad = (
|
337 |
+
-(1.0 / bandwidth)
|
338 |
+
* RectangleFunction.apply((x - threshold) / bandwidth)
|
339 |
+
* grad_output
|
340 |
+
)
|
341 |
+
return x_grad, threshold_grad, None # None for bandwidth
|
342 |
+
|
343 |
+
class JumpReLUSAE(BaseSAE):
|
344 |
+
def __init__(self, config: SAEConfig):
|
345 |
+
super().__init__(config)
|
346 |
+
self.jumprelu = JumpReLU(
|
347 |
+
feature_size=config.dict_size,
|
348 |
+
bandwidth=config.bandwidth,
|
349 |
+
device=config.device if hasattr(config, 'device') else 'cpu'
|
350 |
+
)
|
351 |
+
|
352 |
+
def forward(self, x, use_pre_enc_bias=False):
|
353 |
+
x, x_mean, x_std = self.preprocess_input(x)
|
354 |
+
if use_pre_enc_bias:
|
355 |
+
x = x - self.b_dec
|
356 |
+
pre_activations = torch.relu(x @ self.W_enc + self.b_enc)
|
357 |
+
feature_magnitudes = self.jumprelu(pre_activations)
|
358 |
+
|
359 |
+
x_reconstructed = feature_magnitudes @ self.W_dec + self.b_dec
|
360 |
+
|
361 |
+
return self.get_loss_dict(x, x_reconstructed, feature_magnitudes, x_mean, x_std)
|
362 |
+
|
363 |
+
def get_loss_dict(self, x, x_reconstruct, acts, x_mean, x_std):
|
364 |
+
l2_loss = (x_reconstruct.float() - x.float()).pow(2).mean()
|
365 |
+
|
366 |
+
l0 = StepFunction.apply(acts, self.jumprelu.log_threshold, self.config.bandwidth).sum(dim=-1).mean()
|
367 |
+
l0_loss = self.config.l1_coeff * l0
|
368 |
+
l1_loss = l0_loss
|
369 |
+
|
370 |
+
loss = l2_loss + l1_loss
|
371 |
+
num_dead_features = (
|
372 |
+
self.num_batches_not_active > self.config.n_batches_to_dead
|
373 |
+
).sum()
|
374 |
+
|
375 |
+
sae_out = self.postprocess_output(x_reconstruct, x_mean, x_std)
|
376 |
+
per_token_l2_loss_A = (x_reconstruct.float() - x.float()).pow(2).sum(-1).squeeze()
|
377 |
+
total_variance_A = (x.float() - x.float().mean(0)).pow(2).sum(-1).squeeze()
|
378 |
+
explained_variance = (1 - per_token_l2_loss_A / total_variance_A).mean()
|
379 |
+
output = {
|
380 |
+
"sae_out": sae_out,
|
381 |
+
"feature_acts": acts,
|
382 |
+
"num_dead_features": num_dead_features,
|
383 |
+
"loss": loss,
|
384 |
+
"l1_loss": l1_loss,
|
385 |
+
"l2_loss": l2_loss,
|
386 |
+
"l0_norm": l0,
|
387 |
+
"l1_norm": l0,
|
388 |
+
"explained_variance": explained_variance,
|
389 |
+
}
|
390 |
+
return output
|