红尘
d73ff9b0fb
Deploy Site / deploy-vercel (push) Has been cancelled
Deploy Site / deploy-docs (push) Has been cancelled
Docker / shell lint / Lint Dockerfile (hadolint) (push) Has been cancelled
Docker / shell lint / Lint docker/ shell scripts (shellcheck) (push) Has been cancelled
Docker Build and Publish / build-amd64 (push) Has been cancelled
Docker Build and Publish / build-arm64 (push) Has been cancelled
Lint (ruff + ty) / ruff + ty diff (push) Has been cancelled
Lint (ruff + ty) / ruff enforcement (blocking) (push) Has been cancelled
Lint (ruff + ty) / Windows footguns (blocking) (push) Has been cancelled
Nix Lockfile Fix / auto-fix-main (push) Has been cancelled
Nix Lockfile Fix / fix (push) Has been cancelled
Nix / nix (macos-latest) (push) Has been cancelled
Nix / nix (ubuntu-latest) (push) Has been cancelled
OSV-Scanner / Scan lockfiles (push) Has been cancelled
Build Skills Index / build-index (push) Has been cancelled
Tests / test (1) (push) Has been cancelled
Tests / test (2) (push) Has been cancelled
Tests / test (3) (push) Has been cancelled
Tests / test (4) (push) Has been cancelled
Tests / test (5) (push) Has been cancelled
Tests / test (6) (push) Has been cancelled
Tests / e2e (push) Has been cancelled
uv.lock check / uv lock --check (push) Has been cancelled
Docker Build and Publish / merge (push) Has been cancelled
Build Skills Index / trigger-deploy (push) Has been cancelled
Tests / save-durations (push) Has been cancelled
70 lines
2.0 KiB
Markdown
70 lines
2.0 KiB
Markdown
# SAELens Reference Documentation
|
||
|
||
This directory contains comprehensive reference materials for SAELens.
|
||
|
||
## Contents
|
||
|
||
- [api.md](api.md) - Complete API reference for SAE, TrainingSAE, and configuration classes
|
||
- [tutorials.md](tutorials.md) - Step-by-step tutorials for training and analyzing SAEs
|
||
|
||
## Quick Links
|
||
|
||
- **GitHub Repository**: https://github.com/jbloomAus/SAELens
|
||
- **Neuronpedia**: https://neuronpedia.org (browse pre-trained SAE features)
|
||
- **HuggingFace SAEs**: Search for tag `saelens`
|
||
|
||
## Installation
|
||
|
||
```bash
|
||
pip install sae-lens
|
||
```
|
||
|
||
Requirements: Python 3.10+, transformer-lens>=2.0.0
|
||
|
||
## Basic Usage
|
||
|
||
```python
|
||
from transformer_lens import HookedTransformer
|
||
from sae_lens import SAE
|
||
|
||
# Load model and SAE
|
||
model = HookedTransformer.from_pretrained("gpt2-small", device="cuda")
|
||
sae, cfg_dict, sparsity = SAE.from_pretrained(
|
||
release="gpt2-small-res-jb",
|
||
sae_id="blocks.8.hook_resid_pre",
|
||
device="cuda"
|
||
)
|
||
|
||
# Encode activations to sparse features
|
||
tokens = model.to_tokens("Hello world")
|
||
_, cache = model.run_with_cache(tokens)
|
||
activations = cache["resid_pre", 8]
|
||
|
||
features = sae.encode(activations) # Sparse feature activations
|
||
reconstructed = sae.decode(features) # Reconstructed activations
|
||
```
|
||
|
||
## Key Concepts
|
||
|
||
### Sparse Autoencoders
|
||
SAEs decompose dense neural activations into sparse, interpretable features:
|
||
- **Encoder**: Maps d_model → d_sae (typically 4-16x expansion)
|
||
- **ReLU/TopK**: Enforces sparsity
|
||
- **Decoder**: Reconstructs original activations
|
||
|
||
### Training Loss
|
||
`Loss = MSE(original, reconstructed) + L1_coefficient × L1(features)`
|
||
|
||
### Key Metrics
|
||
- **L0**: Average number of active features (target: 50-200)
|
||
- **CE Loss Score**: Cross-entropy recovered vs original model (target: 80-95%)
|
||
- **Dead Features**: Features that never activate (target: <5%)
|
||
|
||
## Available Pre-trained SAEs
|
||
|
||
| Release | Model | Description |
|
||
|---------|-------|-------------|
|
||
| `gpt2-small-res-jb` | GPT-2 Small | Residual stream SAEs |
|
||
| `gemma-2b-res` | Gemma 2B | Residual stream SAEs |
|
||
| Various | Search HuggingFace | Community-trained SAEs |
|