Hi, I need to read mps file and then call glpk(c, a, b, lb, ub, ctype, vartype, sense, param) .
In the mps files of MIPLIB, the MIP problems are not standard form , now I need to reform it so that the glpk can get correct input arguments for (c, a, b, lb, ub, ctype, vartype, sense, param). I have very large matrix , so how to load these data for glpk such that I can get input arguments for function [xopt, fmin, status, extra] = glpk (c, a, b, lb, ub, ctype, vartype, sense, param) How to transform the MIP to standard forms such that glpk can solve it ? Because I need to do some modifications on the original MIP problems , I need to get its components such as constrain matrix so that I can change it for the following operations. Jack Nov. 29 2008 Marc Goetschalckx wrote: > > I am writing an identical GLPK problem out in MPS format and LP format > from the API. I then read and solve the models with glpsol. The LP > model solves correctly. The MPS model solves but has objective function > zero. A similar behavior occurred in earlier version unless the > parameter LPS_K_MPSOBJ was set to 1. However, the function > lpx_set_int_parm is no longer available in version 4.32. How do I > specify the objective function in the MPS model with version 4_32 (and I > assume the current version as well). The following lines are the output > of the LP and the MPS models solved with glpsol. > Thanks > > glpsol_4_32 --freemps VRP100_best.mps > glp_read_mps: reading problem data from `VRP100_best.mps'... > glp_read_mps: problem VRP100_Best > glp_read_mps: 102 rows, 9 columns, 108 non-zeros > glp_read_mps: 8 integer columns, all of which are binary > glp_read_mps: 232 records were read > ipp_basic_tech: 102 row(s) and 9 column(s) removed > ipp_reduce_bnds: 1 pass(es) made, 0 bound(s) reduced > ipp_basic_tech: 0 row(s) and 0 column(s) removed > ipp_reduce_coef: 1 pass(es) made, 0 coefficient(s) reduced > Objective value = 0 > INTEGER OPTIMAL SOLUTION FOUND BY MIP PRESOLVER > Time used: 0.0 secs > Memory used: 0.1 Mb (61348 bytes) > > glpsol_4_32 --cpxlp VRP100_best.lp > glp_read_lp: reading problem data from `VRP100_best.lp'... > glp_read_lp: 101 rows, 9 columns, 108 non-zeros > glp_read_lp: 8 integer columns, all of which are binary > glp_read_lp: 134 lines were read > ipp_basic_tech: 101 row(s) and 9 column(s) removed > ipp_reduce_bnds: 1 pass(es) made, 0 bound(s) reduced > ipp_basic_tech: 0 row(s) and 0 column(s) removed > ipp_reduce_coef: 1 pass(es) made, 0 coefficient(s) reduced > Objective value = 113800.9085 > INTEGER OPTIMAL SOLUTION FOUND BY MIP PRESOLVER > Time used: 0.0 secs > Memory used: 0.1 Mb (53324 bytes) > > > > _______________________________________________ > Help-glpk mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/help-glpk > > -- View this message in context: http://www.nabble.com/MPS-model-has-zero-objective-function-in-version-4_32-tp20590013p20753295.html Sent from the Gnu - GLPK - Help mailing list archive at Nabble.com. _______________________________________________ Help-glpk mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-glpk
