Some fixes / cleanup for BERT example (#269)

* some fixes/cleaning for bert + test

* nit
This commit is contained in:
Awni Hannun
2024-01-09 08:44:51 -08:00
committed by GitHub
parent 6759dfddf1
commit bbd7172eef
4 changed files with 77 additions and 117 deletions

View File

@@ -2,9 +2,15 @@
An implementation of BERT [(Devlin, et al., 2019)](https://aclanthology.org/N19-1423/) within MLX.
## Downloading and Converting Weights
## Setup
The `convert.py` script relies on `transformers` to download the weights, and exports them as a single `.npz` file.
Install the requirements:
```
pip install -r requirements.txt
```
Then convert the weights with:
```
python convert.py \
@@ -30,49 +36,20 @@ tokens = {key: mx.array(v) for key, v in tokens.items()}
output, pooled = model(**tokens)
```
The `output` contains a `Batch x Tokens x Dims` tensor, representing a vector for every input token.
If you want to train anything at a **token-level**, you'll want to use this.
The `output` contains a `Batch x Tokens x Dims` tensor, representing a vector
for every input token. If you want to train anything at a **token-level**,
you'll want to use this.
The `pooled` contains a `Batch x Dims` tensor, which is the pooled representation for each input.
If you want to train a **classification** model, you'll want to use this.
The `pooled` contains a `Batch x Dims` tensor, which is the pooled
representation for each input. If you want to train a **classification**
model, you'll want to use this.
## Comparison with 🤗 `transformers` Implementation
In order to run the model, and have it forward inference on a batch of examples:
## Test
You can check the output for the default model (`bert-base-uncased`) matches the
Hugging Face version with:
```sh
python model.py \
--bert-model bert-base-uncased \
--mlx-model weights/bert-base-uncased.npz
```
Which will show the following outputs:
```
MLX BERT:
[[[-0.52508914 -0.1993871 -0.28210318 ... -0.61125606 0.19114694
0.8227601 ]
[-0.8783862 -0.37107834 -0.52238125 ... -0.5067165 1.0847603
0.31066895]
[-0.70010054 -0.5424497 -0.26593682 ... -0.2688697 0.38338926
0.6557663 ]
...
```
They can be compared against the 🤗 implementation with:
```sh
python hf_model.py \
--bert-model bert-base-uncased
```
Which will show:
```
HF BERT:
[[[-0.52508944 -0.1993877 -0.28210333 ... -0.6112575 0.19114678
0.8227603 ]
[-0.878387 -0.371079 -0.522381 ... -0.50671494 1.0847601
0.31066933]
[-0.7001008 -0.5424504 -0.26593733 ... -0.26887015 0.38339025
0.65576553]
...
python test.py
```