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)
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