one major issue was that QSE solving was only running at each partition. This was creating effectivley infinite sources of partitioned species. Now we partition when engine updates are triggered, however, solveQSEAbundance is called every timestep. This has major performance implications and so has required a lot of optimization to make it even somewhat viable. For now construction is much slower. Time per iteration is still slower than it was before; however, it is tractable. There is also currently too much stiffness in the network. This is likeley a bug that was introduced in this refactoring which will be addressed soon.
Engine Partitioning trigger now properly throws on both increased convergence failures and a timestep collapse (timestep collapsing more than a factor of 1/100th the average value for the past 10 steps)
This entailed a major rewrite of the composition handling from each engine and engine view along with the solver and primer. The intent here is to let Compositions be constructed from the same extensive property which the solver tracks internally. This addressed C0 discontinuity issues in the tracked molar abundances of species which were introduced by repeadidly swaping from molar abundance space to mass fraction space and back. This also allowed for a simplification of the primeNetwork method. Specifically the mass borrowing system was dramatically simplified as molar abundances are extensive.
The policy system provides a way for users to ensure that they get a network with certain traits. For example being sure that the network they get has all of the proton proton reactions in its base reaction set. This is an extensible system which is intended to be used by researchers to build various determanistic network policies to make network results more reproducable
GridFire can now (to a very limited degree) approximate the abilities of pynucastro in so far as it can not just solve an engine but it can also export it to a python file. Currently only the rates are exported so no solver can yet be used (since things like the rest of the RHS and the jacobian are missing) but this is a step in that direction
added new trigger which throws on convergence failures. This also required adding a new "step" method for other triggers which gets called every step instead of every trigger throw. The ConvergenceFailureTrigger has sucsessgully let teh engine evolve to 10Gyr without any meaningful growth of convergence failures.
Mirroring what was done in fourdst (see fourdst/tree/v0.8.5) we have added a temporary patch to let python bindings work on mac while the meson-python folks resolve the duplicate rpath issue in the shared object file
Passing weak rate interpolator as an std::optional was resulting in use-after-free bugs due to std::optional making a copy of WeakRateInterpolator. This resulted in segfaults. Since we have the new construction semantics with flags this is no longer needed so the optional argument has been removed in favor of a simple const &
Added new ways to select exactly what types of reactions (strong, beta+, beta-, electron capture, positron capture, or any combination thereof) can be turned on at network construction time. There are a few quality of life masks added as well such as weak which addes all weak type reactions, and all which adds weak + strong reactions. The default is to just add strong reactions for now.
these allow the atomic weak rate to be used with the current sparsity code. Note also that this commit reintroduces the full weak reaction set which does introduce an enormouse degree of stiffness which will need to be filtered out. What this means is that this commit practically cannot evolve a network due to this stiffness
previously I had neglected to actually call the heuristic removing weak reaclib reactions. This is now called properly. Therefore it is this commit which actually prevents weak reaclib reactions from getting registered
reaclib provides a small number of weak reactions which allow for things like closing the CNO cycle. Howevever, they are not of the same quality as the WRL reactions. Therefore we ignore them during network construction through a simple heuristic (is the mass number the same on both sides and is there exactly 1 product and reactant (ignoring the beta +/- particle). This is one of the final steps before actually enabling weak reactions since withouty turning these off we would be double counting weak reactions.
previousl the sparsity calculations for the jacobian matrix were completly broken. The method subgraph_sparsity was returning that all derivities were only depenednt on temperature and density. It should have been reporting that they also depended on some of the abundances. This was resolved by switching to a different structural sparsity engine (for_jac_sparsity). This bug had turned the solver into a fixed point iteration solver which failed for the stiff system we have. Now that it is resolved the solver can once again evolved over Gyr timescales.
Previously, due to a indexing issue, reverse rates were sometimes included in the forward rates for strong reactions. This lead to erroneously high molar reaction flows for some reactions. This has been resolved so now each logical reaction set is guareteed to include only either forward reactions or reverse reactions (not both)
previously recordADTape was duplicating a lot of work which recordEpsTape also needed to do. Now all derivs are being recorded into m_rhsADFun so that only one tape recording phase is needed per network build stage.
essentially all callers can now inform the graph engine about which species they hold active and graph engine then uses those to define a sparsity pattern and only calculate the jacobian along that sparsity pattern
All jacobian calculations were broken because the indexing used to record the AD tape was broken (see not parallel to) the indexing used by the composition object. A fix for this was to sort the network species by mass. However, more generally we should introduce a mechanism to ensure these two indexed sets always remain parallel
This fourdst version bump brings the libcomposition v1.9.0 which brings the abstract base class CompositionAbstract. This will allow us to impliment overrides which return specific molarAbundances skirting around Composition internal checks. This is for the purpose of allowing unrestricted molar flow when ccalculating the destruction rate constant for particular species.
bigs were introduced by the interface change from accepting raw molar abundance vectors to using the composition vector. This commit resolves many of these, including preformant ways to report that a species is not present in the composition and unified index lookups using composition object tooling.
BREAKING CHANGE:
Major weak rate progress which includes: A refactor of many of the public interfaces for GridFire Engines to use composition objects as opposed to raw abundance vectors. This helps prevent index mismatch errors. Further, the weak reaction class has been expanded with the majority of an implimentation, including an atomic_base derived class to allow for proper auto diff tracking of the interpolated table results. Some additional changes are that the version of fourdst and libcomposition have been bumped to versions with smarter caching of intermediate vectors and a few bug fixes.
