A custom integrator is required to handle the theta^n term in the lane emden equation, that is written as NonlinearPowerIntegrator which is a mfem::NonlinearFormIntegrator and defines methods to assemble its element vector (function value) and element gradient matrix (jacobian). This is then, along with built in mfem vectors for M Q and D, incorporated into the PolytropeOperator which defines methods for Mult (calculate the residuals of the variational form) and GetGradient (find the jacobian of the system)
The build system now passes compiler directives based on the mode being build. By default data is stored in the source root (and this is encoded into the compiled binary). However, if building in user mode then data is assumed to be at the meson install prefix data directory
At many points in the code we may want configurable options, the Config class usses a yaml file to make this easy. It also allows for namespace references "opac:lowtemp:file" etc...
const needds to be accessed all throughout so it has been changed to a singleton to allow for more efficient usage
BREAKING CHANGE: Any previous loads to const will break, also constant->Constant and constants->Constants
we will use meson as the build system for this project. Added a rough outline of this which builds source, libraries, and links them to tests (along with the google test library for testing). meson will be setup and compiled with ./mk.
