hypre is required for parallel MFEM usage and hypre requires MPI. Both of these have been added as dependecies. MPI is added as a dependency in the same manner as boost (i.e. with an install script which checks for system installation and provides a way that the user can initiate a system installation). The MPI install script has been incorporated with the mk script. Hypre has been added as a subproject.
In general we may want to enforce that a config file is explicitly loaded before any access is requested. However, there are times when this is non ideal behavior. We introduce a compile time flag (CONFIG_HARSH, and CONFIG_WARN). If config hars is defined then a runtime error will be thrown if a config value is requested before the config file has been loaded. If Config warn is defined (and config harsh is not) then a warning will be printed, otherwise nothing will happen. If either warn or nothing is defined this means that the default values defined in the get methods will be used.
Note that the meson build system has had an option added -Dconfig_error_handling=["none", "warn", "harsh"] (default="none") which can be used to manage these compile time options. In general release builds should have this disabled while debug builts should have it set to harsh.
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)
tboudreaux:feature/mixedPolytrope implimented a fix to bring old style opat-core calls to the more up to date style. This change has been fast forwarded into main
Composition can now be placed in either number fraction or mass fraction mode and can (after finalization) convert between them. Subsets of compositions can also be made. Normalization has also been added to finalize. Tests have been added
