TextNAS

Introduction

This is the implementation of the TextNAS algorithm proposed in the paper TextNAS: A Neural Architecture Search Space tailored for Text Representation. TextNAS is a neural architecture search algorithm tailored for text representation, more specifically, TextNAS is based on a novel search space consists of operators widely adopted to solve various NLP tasks, and TextNAS also supports multi-path ensemble within a single network to balance the width and depth of the architecture.

The search space of TextNAS contains:

* 1-D convolutional operator with filter size 1, 3, 5, 7 
* recurrent operator (bi-directional GRU) 
* self-attention operator
* pooling operator (max/average)

Following the ENAS algorithm, TextNAS also utilizes parameter sharing to accelerate the search speed and adopts a reinforcement-learning controller for the architecture sampling and generation. Please refer to the paper for more details of TextNAS.

Preparation

Prepare the word vectors and SST dataset, and organize them in data directory as shown below:

textnas
├── data
│   ├── sst
│   │   └── trees
│   │       ├── dev.txt
│   │       ├── test.txt
│   │       └── train.txt
│   └── glove.840B.300d.txt
├── dataloader.py
├── model.py
├── ops.py
├── README.md
├── search.py
└── utils.py

The following link might be helpful for finding and downloading the corresponding dataset:

Examples

Search Space

Example code

# In case NNI code is not cloned. If the code is cloned already, ignore this line and enter code folder.
git clone https://github.com/Microsoft/nni.git

# search the best architecture
cd examples/nas/textnas

# view more options for search
python3 search.py -h

After each search epoch, 10 sampled architectures will be tested directly. Their performances are expected to be 40% - 42% after 10 epochs.

By default, 20 sampled architectures will be exported into checkpoints directory for next step.

retrain

# In case NNI code is not cloned. If the code is cloned already, ignore this line and enter code folder.
git clone https://github.com/Microsoft/nni.git

# search the best architecture
cd examples/nas/textnas

# default to retrain on sst-2
sh run_retrain.sh

Reference

TextNAS directly uses EnasTrainer, please refer to ENAS for the trainer APIs.