Modulus Tool-Chain (MTC) [Beta]

[See A Conceptual Framework for PINNs for a more detailed project motivation]

The MTC suite of utilities aims to simplify work on Physics Informed Neural Networks and, eventually, Physics ML more broadly (it does not support neural operators currently). The goal is to provide sufficient support for the whole workflow in addition to a simplified API. More specifically

• Project management facilities

  • Creation, cloning / replicating / extending projects
  • Introspection and analysis
  • Training process control (start/stop, multi-stage training, history clearing, multi-gpu/node)
  • Using the trained models easily (Inference)
  • Simplified configuration initialization and validation (e.g. a Configurator GUI)

• Simplified API that clearly separates problem definition (problem.py) from training (solving the problem) and inference (using the solution)

At a high level, the toolchain is intended to work as the following diagram shows:

Features

1. Basic 1D, 2D, 3D geometry and CSG operations and mesh geometry from STL files [tutorial]
2. Sub domain creation with ability to parameterize PDEs [tutorial]
3. Pointwise constraints implemented in Problem API [docs]
4. Automatic initialization of default configuration specific to problem
5. Compile targets: training, inference, sampler, train-sampled
6. Automatic rewriting of problem to equivalent formulation but only using first derivatives of neural networks (tutorial)
7. Configuration UI allows: detailed configuration and quick multi-stage training (e.g., transfer learning) [tutorial]
8. Multi-gpu training; e.g., mtc train --ngpus 2
9. Limited support for FNO/PINO models

Installation

Environment

Create a new environment, activate it, and install requirements

conda create -n mtcenv python=3.8 -y
conda activate mtcenv
pip install -r requirements.txt

Note: this will install modulus.sym from git+https://github.com/NVIDIA/modulus-sym.git@main

Setup

Some additional paths need to be set up--to access the mtc cli tool. Run (in the top-level dir of this repo)

source set-up-env.sh

Then the Modulus Tool Chain becomes available. Run mtc --help for a list of commands, and mtc [command] --help for help on a specific command.

Start the Jupyter Lab environment at the root of the repo with

jupyter lab --ip="*"  --no-browser --NotebookApp.token='' --notebook-dir=/ --NotebookApp.allow_origin='*'

or simply

jupyter lab

Once insiude the Jupyter Lab environment, make sure that the conda environment is properly set:

conda activate mtcenv

Using the toolchain

A PINN tutorial is available inside the environment (see setup above).

1. Create a new project with mtc create myproject -- this creates and populates a directory called myproject
2. Inside the Jupyter Lab environment, navigate to myproject/docs/tutorial and right-click on index.md to select "Open With"/"Markdown Preview"

The PINN Problem API and the PINO Problem API are also documented.

Release Notes

v23.05

1. Second release (beta)
2. Simplified installation (no container needed); works in WSL 2.0 under Windows
3. Initial (experimental support) for Physics-Informed FNOs (PINOs)

v23.02

1. First release (alpha)

References

[1] Modulus Documentation: https://docs.nvidia.com/deeplearning/modulus/index.html

[2] Modulus container image from ngc.nvidia.com: https://catalog.ngc.nvidia.com/orgs/nvidia/teams/modulus/containers/modulus

Pavel Dimitrov pdimitrov@nvidia.com