Re: [Help-glpk] MIP Solvers (i.e CBC, CPLEX, GLPK, GUROBI, LPSOLVE, SCIPC, SCIPL, SCIPS and XPRESS) Benchmark

[Noli Sicad]

Hi Andrew,

> When you pass mps to glpsol, the optimization direction is minimization
> by default, so you need to specify the --max option to tell glpsol to
> maximize rather than minimize.

OK. I got it now.

#####

Nolis-MacBook-Pro:Case_Studies nsicad$ glpsol --freemps
TimberHarvestModel_0025p_freemps.mps --max

GLPSOL: GLPK LP/MIP Solver, v4.47
Parameter(s) specified in the command line:
 --freemps TimberHarvestModel_0025p_freemps.mps --max
Reading problem data from `TimberHarvestModel_0025p_freemps.mps'...
Problem: TimberHarvestModel_0025p
Objective: Discounted_Net_Value
464 rows, 255 columns, 1421 non-zeros
249 integer variables, all of which are binary
1727 records were read
GLPK Integer Optimizer, v4.47
464 rows, 255 columns, 1421 non-zeros
249 integer variables, all of which are binary
Preprocessing...
418 rows, 255 columns, 1181 non-zeros
249 integer variables, all of which are binary
Scaling...
 A: min|aij| =  9.750e-01  max|aij| =  1.022e+04  ratio =  1.048e+04
GM: min|aij| =  4.933e-01  max|aij| =  2.027e+00  ratio =  4.109e+00
EQ: min|aij| =  2.441e-01  max|aij| =  1.000e+00  ratio =  4.097e+00
2N: min|aij| =  1.233e-01  max|aij| =  1.491e+00  ratio =  1.209e+01
Constructing initial basis...
Size of triangular part = 418
Solving LP relaxation...
GLPK Simplex Optimizer, v4.47
418 rows, 255 columns, 1181 non-zeros
*     0: obj =   3.468641975e+03  infeas =  0.000e+00 (0)
*   205: obj =   3.501953549e+05  infeas =  0.000e+00 (0)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
+   205: mip =     not found yet <=              +inf        (1; 0)
+  8941: >>>>>   3.085164198e+05 <=   3.487251184e+05  13.0% (1247; 46)
+ 20699: >>>>>   3.357080247e+05 <=   3.485231119e+05   3.8% (2973; 127)
+ 64121: mip =   3.357080247e+05 <=   3.479684199e+05   3.7% (8936; 1182)

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Now, I wonder how other solvers would have this maximization option.

Thanks.

Noli