| --- |
| license: mit |
| library_name: pytorch |
| tags: |
| - divisibility |
| - arithmetic |
| - custom-architecture |
| - digit-histogram |
| --- |
| |
| # Div3Net — Divisibility-by-3 Classifier |
|
|
| A custom PyTorch classifier that predicts whether a non-negative |
| integer is divisible by 3. Uses a digit histogram encoding: the input |
| is a count of each digit (0-9) plus the total digit count, so the |
| network cannot see digit order — it must rediscover the digit-sum rule. |
|
|
| ## Architecture |
|
|
| - Input: 10 digit counts + 1 normalized digit-count feature |
| - Body: `layers` hidden layers of `hidden` units, ReLU between them |
| - Output: single logit |
| - Params: ~135K per model, ensemble of N models |
|
|
| ## Checkpoint format |
|
|
| The file `div3_model.pt` is a dict with: |
|
|
| - `format_version`: 4 |
| - `config`: `{MAX_DIGITS, hidden, layers, num_models, encoding}` |
| - `state_dicts`: list of `state_dict` objects, one per ensemble member |
|
|
| Load with the `model.py` file from the same project. |
|
|
| ## Performance |
|
|
| ~99.8% on held-out random numbers spanning 1 to 50 digits. |
|
|
| ## Test |
| Note: this is just for testing PyTorch. |
