Forum Discussion
combining mmxprs and/or nlsolv with mmquad or mmnl
I have two questions about combining mmxprs and/or nlsolv with mmquad or mmnl in Mosel: If I use the Xpress solver (mmxprs), can I trust that it will always detect that a constraint or objective is ...
A few add-on notes:
- mmquad vs mmnl: as was already said, usually we recommend using mmnl as it has more functionality and it is now as efficient as mmquad for handling quadratic constraints (this was not the case in earlier versions of mmnl)
- matrix export: the core functionality of Mosel only supports pure linear problems - this is what gets written out by 'exportprob'. The full solver problem is output by loading it into the optimiser using 'loadprob', followed by 'writeprob'. When working with nlsolv the module itself does not provide matrix export functionality, but the solver that you use through it may be able to write out matrices, for example with 'amplxpress', you can achieve this through the solver options setting:
setparam("nl_options", "writeprob=testout.lp") ! LP format matrix file
or
setparam("nl_options", "writeprob=testout.mps") ! MPS format matrix file
