README.md

---
tags:
- lmprobe
- activations
- interpretability
- meta-llama-llama-3.1-405b
task_categories:
- feature-extraction
language:
- en
license: cc-by-4.0
---

# meta-llama/Llama-3.1-405B — Activation Dataset

Cached activations extracted from [`meta-llama/Llama-3.1-405B`](https://huggingface.co/meta-llama/Llama-3.1-405B) (revision `b906e4dc842aa489c962f9db26554dcfdde901fe`).

LateNet v0 activations for Llama 3.1 405B base (all layers, full sequence)

## Contents

| Tensor | Layers | Dim | Pooling | Shards | Row Bytes |
|--------|--------|-----|---------|--------|-----------|
| hidden_layers | 0-125 | 16384 | - | 20 | - |

- **Prompts:** 23724
- **Format version:** 2.0

## Load with lmprobe

```python
from lmprobe import load_activations, Probe

acts = load_activations("alliedtoasters/latenet-v0-activations-llama3.1-405b-base", layers=[0])
probe = Probe(classifier="logistic_regression", random_state=42)
probe.fit_from_activations(acts[0], labels)
```

## Load without lmprobe (standalone)

```python
import json
import pyarrow.parquet as pq
from safetensors import safe_open

# Load the index — all metadata is embedded in the Parquet schema
table = pq.read_table("index/train-00000-of-00001.parquet")
df = table.to_pandas()
meta = json.loads(table.schema.metadata[b"lmprobe:tensors"])

# Get layer 0 activation for prompt 0
row = df.iloc[0]
pattern = meta["hidden_layers"]["file_pattern"]
path = pattern.format(layer=0, shard=row["shard_index"])
with safe_open(path, framework="pt") as f:
    vec = f.get_tensor("hidden.layer_0")[row["row_offset"]]
    # vec.shape: (16384,)
```

> **Full-sequence dataset:** The `shard_index` / `row_offset` columns always address the **last-token** pooled vector. For per-token access, use the `token_shard_ids` and `token_shard_offsets` list columns — see the `lmprobe:tensors` schema metadata for details.

## Load with HF Datasets

```python
from datasets import load_dataset

# Shows prompt text + labels in Dataset Viewer
ds = load_dataset("alliedtoasters/latenet-v0-activations-llama3.1-405b-base")
print(ds["train"][0])  # {"text": "...", "label": ..., ...}
```

## Provenance

- **lmprobe version:** 0.9.2
- **Extraction backend:** local
- **Created:** 2026-04-04T16:35:14.904340+00:00
- **PyTorch:** 2.11.0+cu130
- **Transformers:** 5.4.0