Exchangable solvers

[draeger]

At the moment, a default solver (GLPK) is used as the backend for flux balance analysis. It should be possible to make this exchangable. Implement support for multiple solvers.

[dyrpsf]

Hi @draeger ,
I’d like to work on this issue.

My current understanding:

• The FBA implementation currently uses GLPK as the default LP backend via SCPSolver.
• SBSCL also depends on other solver packs (e.g. LPSolve, possibly CPLEX), but these are not yet
  exposed in the FBA API.

Planned approach:

• Inspect the FBA code under org.simulator.fba (especially FluxBalanceAnalysis and related
  classes) and the example usages.
• Introduce a small abstraction (e.g. an enum or strategy) to select the LP solver backend,
  keeping GLPK as the default.
• Add an API for users to request a particular solver (e.g. GLPK, LPSOLVE, CPLEX) when creating
  an FBA instance, and route the solver construction through this abstraction.
• Add/adjust tests or examples to show using at least two different solvers.

If you have preferences about how solver selection should be configured (constructor parameter,
setter, configuration object, etc.), or about which solvers you’d most like to support first,
I’d be happy to follow your guidance.

[dyrpsf]

Hi @draeger ,

I’ve opened a PR for this: #99. It makes the FBA backend solver pluggable while keeping GLPK as the default.

[xts-Michi]

OptSolvX is in the final phase of integration into SBSCL with the goal of introducing multiple interchangeable solver backends.
Until it is fully integrated, this issue will remain open.

[dyrpsf]

OptSolvX is in the final phase of integration into SBSCL with the goal of introducing multiple interchangeable solver backends. Until it is fully integrated, this issue will remain open.

Thanks for the clarification regarding OptSolvX and the new FBA backend.

I understand that the “exchangeable solvers” functionality will now be provided via the
OptSolvX-based design, so my previous PR (#99) has been closed as redundant. I’ll keep an eye
on the OptSolvX integration and would be happy to help with any follow‑up tasks or smaller
issues once it’s fully integrated into SBSCL.