amrex-astro / stvar

Space-Time Variable Code Generator and Solver

Space-Time Variable Code Generator and Solver

This code package contains a Sympy-based code generator that creates C++ code for solving PDEs with finite-differencing.

The integration of these PDEs in time is implemented using the Method of Lines with a Runge-Kutta integrator.

We discretize in space using finite differencing with options for various orders. We implement domain decomposition using the AMReX package for adaptive mesh refinement and parallel processing.

A PDE solver generated using the STvAR package will run on CPUs and GPUs using the AMReX performance portability backend.

We include examples based on the wave equation and numerical general relativity.

stvar's Issues

Time Interpolation Order in FillPatch & FillCoarsePatch

Currently in FillPatch & FillCoarsePatch, we are still using the built-in AMReX linear interpolation in time.

We should switch to the 4th order interpolation like we did for FillIntermediatePatch.

This applies when we're making a new fine level or remaking an existing fine level.

This change would make sure that when we need to interpolate from coarse to fill a subset of the fine level, we will first interpolate coarse data to 4th order in time, then interpolate in space to fill the fine cells.