> Does anyone know of a theoretical size limit for a non-integer GLPK > problem?
Theoretically the problem size is limited by 100,000,000 rows and columns and 500,000,000 non-zero constraint coefficients; this is because glpk is a 32-bit application in the sense that it uses 32-bit integers to access array elements. On the other hand, glpk conforms to ILP32, LLP64 and LP64 programming models, i.e. it allows using 64-bit pointers as well, so the cumulative amount of core memory used may exceed 4Gb. All this, however, does not mean that glpk is able to solve such huge instances for a reasonable time. For pure lp instances the current practical limit is about one million columns and several millions of non-zero constraint coefficients. > At some level, large problems may not be solvable to optimality > in a 'reasonable' amount of time (given available hardware). Very, > very large problems may not be solveable to optimality, perhaps ever. > What is GLPK's limits in terms of the number of constraints that can > be described, etc. Is there a way to feed an array of data (in the > appropriate format) directly into GLPK instead of generating a huge > .MOD file that must be parsed, etc. You can feed glpk with a data file in mps or cplex lp format, or use the glpk api to construct the instance directly in the memory. > Anyone care to mention how large of a problem that they have > solved with GLPK in terms of decision variables, constraints, etc. _______________________________________________ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk