jaxhps 0.0a0

An elliptic PDE solver built with machine learning in mind

ha-hps

A JAX package implementing hardware acceleration for HPS methods in two and three dimensions.

See our preprint on arXiv: Hardware Acceleration for HPS Methods in Two and Three Dimensions

Installation

To install, you can use pip:

pip install jaxhps

The examples require additional packages matplotlib and h5py. If you want to install them automatically, use:

pip install jaxhps[examples]

Documentation

https://jaxhps.readthedocs.io/en/latest/

Examples

hp convergence on 2D problems with known solutions

Shows convergence using uniform quadtrees using both DtN matrices and ItI matrices.

python examples/hp_convergence_2D_problems.py --DtN --ItI

High-wavenumber scattering problem

First, run the matlab script examples/driver_gen_SD_matrices.m. This will generate and save exterior single and double-layer kernel matrices. These matrices are necessary to define a boundary integral equation for the scattering problem. Once in place, we can run the script:

python examples/wave_scattering_compute_reference_soln.py --scattering_potential gauss_bumps -k 100 --plot_utot

This will generate plots which looks like this, showing the scattering potential and real part and modulus of the total field:

Adaptive discretization on a 3D problem with known solution

We have a script for generating adaptive discretizations on the wavefront problem presented in our paper:

python examples/wavefront_adaptive_discretization_3D.py -p 10 --tol 1e-02 1e-05

This should produce an image showing the computed solution, generated grid, and error map:

Inverse wave scattering using automatic differentiation

We have an implementation of a low-dimensional optimization problem using automatic differentiation:

python examples/inverse_wave_scattering.py --n_iter 25

This is an inverse scattering problem where we try to recover the locations of four Gaussian bumps which make up the scattering potential. Running the code should produce plots showing the optimization variables converging at the centers of the Gaussian bumps in the scattering potential, as well as a plot showing the convergence of the objective function:

Linearized Poisson--Boltzmann equation

Our method can be used to solve the a linearized Poisson-Boltzmann equation, which models the electrostatic properties of a molecule in solution.

python examples/poisson_boltzmann_example.py --tol 1e-01 1e-03 -p 10