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Convolutional Neural Networks for Sentence Classification

Code for the paper Convolutional Neural Networks for Sentence Classification (EMNLP 2014).

Runs the model on Pang and Lee's movie review dataset (MR in the paper). Please cite the original paper when using the data.

Requirements

Code is written in Python (2.7) and requires Theano (0.7).

Using the pre-trained word2vec vectors will also require downloading the binary file from https://code.google.com/p/word2vec/

Data Preprocessing

To process the raw data, run

python process_data.py path

where path points to the word2vec binary file (i.e. GoogleNews-vectors-negative300.bin file). This will create a pickle object called mr.p in the same folder, which contains the dataset in the right format.

Note: This will create the dataset with different fold-assignments than was used in the paper. You should still be getting a CV score of >81% with CNN-nonstatic model, though.

Running the models (CPU)

Example commands:

THEANO_FLAGS=mode=FAST_RUN,device=cpu,floatX=float32 python conv_net_sentence.py -nonstatic -rand
THEANO_FLAGS=mode=FAST_RUN,device=cpu,floatX=float32 python conv_net_sentence.py -static -word2vec
THEANO_FLAGS=mode=FAST_RUN,device=cpu,floatX=float32 python conv_net_sentence.py -nonstatic -word2vec

This will run the CNN-rand, CNN-static, and CNN-nonstatic models respectively in the paper.

Using the GPU

GPU will result in a good 10x to 20x speed-up, so it is highly recommended. To use the GPU, simply change device=cpu to device=gpu (or whichever gpu you are using). For example:

THEANO_FLAGS=mode=FAST_RUN,device=gpu,floatX=float32 python conv_net_sentence.py -nonstatic -word2vec

Example output

CPU output:

epoch: 1, training time: 219.72 secs, train perf: 81.79 %, val perf: 79.26 %
epoch: 2, training time: 219.55 secs, train perf: 82.64 %, val perf: 76.84 %
epoch: 3, training time: 219.54 secs, train perf: 92.06 %, val perf: 80.95 %

GPU output:

epoch: 1, training time: 16.49 secs, train perf: 81.80 %, val perf: 78.32 %
epoch: 2, training time: 16.12 secs, train perf: 82.53 %, val perf: 76.74 %
epoch: 3, training time: 16.16 secs, train perf: 91.87 %, val perf: 81.37 %

Other Implementations

TensorFlow

Denny Britz has an implementation of the model in TensorFlow:

https://github.com/dennybritz/cnn-text-classification-tf

He also wrote a nice tutorial on it, as well as a general tutorial on CNNs for NLP.

Torch

HarvardNLP group has an implementation in Torch.

https://github.com/harvardnlp/sent-conv-torch

Hyperparameters

At the time of my original experiments I did not have access to a GPU so I could not run a lot of different experiments. Hence the paper is missing a lot of things like ablation studies and variance in performance, and some of the conclusions were premature (e.g. regularization does not always seem to help).

Ye Zhang has written a very nice paper doing an extensive analysis of model variants (e.g. filter widths, k-max pooling, word2vec vs Glove, etc.) and their effect on performance.