NVIDIA Neural Modules: NeMo

Neural Modules (NeMo) is a framework-agnostic toolkit for building AI applications powered by Neural Modules. Current support is for PyTorch framework.

A "Neural Module" is a block of code that computes a set of outputs from a set of inputs.

Neural Modules’ inputs and outputs have Neural Type for semantic checking.

An application built with NeMo application is a Directed Acyclic Graph(DAG) of connected modules enabling researchers to define and build new speech and nlp networks easily through API Compatible modules.

Introduction

See this video for a walk-through.

Core Concepts and Features

• NeuralModule class - represents and implements a neural module.
• NmTensor - represents activations which flow between neural modules' ports.
• NeuralType - represents types of modules' ports and NmTensors.
• NeuralFactory - to create neural modules and manage training.
• Lazy execution - when describing activation flow between neural modules, nothing happens until an "action" (such as optimizer.optimize(...) is called.
• Collections - NeMo comes with collections - related group of modules such as nemo_asr (for Speech Recognition) and nemo_nlp for NLP

Requirements

1. Python 3.6 or 3.7
2. Pytorch 1.2 with GPU support
3. NVIDIA APEX: https://github.com/NVIDIA/apex

Documentation NeMo documentation

Getting started

If desired, you can start with NGC PyTorch container which already includes requirements above.

• You can pull it like so: docker pull nvcr.io/nvidia/pytorch:19.08-py3
• And then run: nvidia-docker run -it --rm -v <nemo_github_folder>:/NeMo --shm-size=1g --ulimit memlock=-1 --ulimit stack=67108864 nvcr.io/nvidia/pytorch:19.08-py3
• ``cd /NeMo''

and then continue with the following steps:

1. Clone the repository
2. Go to nemo folder and then: python setup.py install

3. Install collections:

   • ASR collection from collections/nemo_asr:

     1. apt-get install libsndfile1
     2. python setup.py install

   • NLP collection from collections/nemo_nlp: python setup.py install

4. For development you will need to: python setup.py develop instead of python setup.py install in Step (3.2) above
5. Go to examples/start_here to get started with few simple examples

Tutorials

• Speech recognition
• Natural language processing

Unittests

This command runs unittests:

./reinstall.sh
python -m unittest tests/*.py