Dear Bryn, Your mail had to be forwarded manually because you are not subscribed to the list.
Are you able to share a copy of the .lp file used in the examples you showed? Without this it is hard to see exactly what is happening. Best Regards, Chris Matrakidis On 7 March 2018 at 17:41, Andrew Makhorin <[email protected]> wrote: > -------- Forwarded Message -------- > From: Bryn Pickering <[email protected]> > To: [email protected] > Subject: GLPK incorrect results > Date: Wed, 07 Mar 2018 09:31:17 +0000 > > Hi, > > > We've resolutely stuck with GLPK V.4.61 for the past several months in > https://github.com/calliope-project/calliope. The reason is that all our > tests fail for any newer version of GLPK! > > > For LP models, GLPK 4.61 agrees with Gurobi and CPLEX in the objective > function value. However, we get up to orders of magnitude difference > when implementing newer versions of GLPK. > > > We're not applying any solver options in any case. Below are the output > logs for the same model, run through different solvers. This was also an > issue in GLPK v4.63. > > > Best, > > > Bryn > > > > GLPK 4.61 > INFO: GLPSOL: GLPK LP/MIP Solver, v4.61 > INFO: Parameter(s) specified in the command line: > INFO: --write C:\Users\bp325\AppData\Local\Temp\tmp34nbrldr.glpk.raw > --wglp C:\Users\bp325\AppData\Local\Temp\tmpjjn0zc3b.glpk.glp > INFO: --cpxlp C:\Users\bp325\AppData\Local\Temp\tmpcton6cq0.pyomo.lp > INFO: Reading problem data from 'C:\Users\bp325\AppData\Local\ > Temp\tmpcton6cq0.pyomo.lp'... > INFO: 1756 rows, 1178 columns, 4208 non-zeros > INFO: 10728 lines were read > INFO: Writing problem data to 'C:\Users\bp325\AppData\Local\ > Temp\tmpjjn0zc3b.glpk.glp'... > INFO: 8836 lines were written > INFO: GLPK Simplex Optimizer, v4.61 > INFO: 1756 rows, 1178 columns, 4208 non-zeros > INFO: Preprocessing... > INFO: 1109 rows, 672 columns, 2695 non-zeros > INFO: Scaling... > INFO: A: min|aij| = 9.056e-03 max|aij| = 4.000e+00 ratio = 4.417e+02 > INFO: GM: min|aij| = 6.113e-01 max|aij| = 1.636e+00 ratio = 2.676e+00 > INFO: EQ: min|aij| = 3.852e-01 max|aij| = 1.000e+00 ratio = 2.596e+00 > INFO: Constructing initial basis... > INFO: Size of triangular part is 1105 > INFO: 0: obj = 7.036238780e+14 inf = 6.979e+05 (48) > INFO: 78: obj = 7.036315011e+14 inf = 0.000e+00 (0) > INFO: * 363: obj = 3.899735440e+04 inf = 0.000e+00 (0) 3 > INFO: OPTIMAL LP SOLUTION FOUND > INFO: Time used: 0.1 secs > INFO: Memory used: 1.6 Mb (1710595 bytes) > > GLPK 4.65 > INFO: GLPSOL: GLPK LP/MIP Solver, v4.65 > INFO: Parameter(s) specified in the command line: > INFO: --write C:\Users\bp325\AppData\Local\Temp\tmp958qxyz5.glpk.raw > --wglp C:\Users\bp325\AppData\Local\Temp\tmpnffytitk.glpk.glp > INFO: --cpxlp C:\Users\bp325\AppData\Local\Temp\tmp4oma0ezm.pyomo.lp > INFO: Reading problem data from 'C:\Users\bp325\AppData\Local\ > Temp\tmp4oma0ezm.pyomo.lp'... > INFO: 1756 rows, 1178 columns, 4208 non-zeros > INFO: 10728 lines were read > INFO: Writing problem data to 'C:\Users\bp325\AppData\Local\ > Temp\tmpnffytitk.glpk.glp'... > INFO: 8836 lines were written > INFO: GLPK Simplex Optimizer, v4.65 > INFO: 1756 rows, 1178 columns, 4208 non-zeros > INFO: Preprocessing... > INFO: 1109 rows, 672 columns, 2695 non-zeros > INFO: Scaling... > INFO: A: min|aij| = 9.056e-03 max|aij| = 4.000e+00 ratio = 4.417e+02 > INFO: GM: min|aij| = 6.113e-01 max|aij| = 1.636e+00 ratio = 2.676e+00 > INFO: EQ: min|aij| = 3.852e-01 max|aij| = 1.000e+00 ratio = 2.596e+00 > INFO: Constructing initial basis... > INFO: Size of triangular part is 1105 > INFO: 0: obj = 7.036238780e+14 inf = 6.979e+05 (48) > INFO: 78: obj = 7.036315011e+14 inf = 0.000e+00 (0) > INFO: * 314: obj = 4.109718910e+04 inf = 2.782e-12 (0) 2 > INFO: OPTIMAL LP SOLUTION FOUND > INFO: Time used: 0.1 secs > INFO: Memory used: 1.7 Mb (1743619 bytes) > > CPLEX 12.6.3 > Welcome to IBM(R) ILOG(R) CPLEX(R) Interactive Optimizer 12.6.3.0 > INFO: with Simplex, Mixed Integer & Barrier Optimizers > INFO: 5725-A06 5725-A29 5724-Y48 5724-Y49 5724-Y54 5724-Y55 5655-Y21 > INFO: Copyright IBM Corp. 1988, 2015. All Rights Reserved. > INFO: > INFO: Type 'help' for a list of available commands. > INFO: Type 'help' followed by a command name for more > INFO: information on commands. > INFO: > INFO: CPLEX> Logfile 'cplex.log' closed. > INFO: Logfile 'C:\Users\bp325\AppData\Local\Temp\tmpso8i41ok.cplex.log' > open. > INFO: CPLEX> Problem 'C:\Users\bp325\AppData\Local\Temp\tmpmx_estsg.pyomo.lp' > read. > INFO: Read time = 0.03 sec. (0.15 ticks) > INFO: CPLEX> Problem name : C:\Users\bp325\AppData\Local\T > emp\tmpmx_estsg.pyomo.lp > INFO: Objective sense : Minimize > INFO: Variables : 1178 [Nneg: 484, Free: 430, Other: 264] > INFO: Objective nonzeros : 15 > INFO: Linear constraints : 1756 [Less: 923, Greater: 10, Equal: > 823] > INFO: Nonzeros : 4208 > INFO: RHS nonzeros : 60 > INFO: > INFO: Variables : Min LB: 0.0000000 Max UB: 0.0000000 > INFO: Objective nonzeros : Min : 1.000000 Max : 1.000000 > INFO: Linear constraints : > INFO: Nonzeros : Min : 0.002000000 Max : 1.000000e+009 > INFO: RHS nonzeros : Min : 1.000000 Max : 614033.0 > INFO: CPLEX> Tried aggregator 1 time. > INFO: LP Presolve eliminated 942 rows and 584 columns. > INFO: Aggregator did 254 substitutions. > INFO: Reduced LP has 560 rows, 340 columns, and 1501 nonzeros. > INFO: Presolve time = 0.02 sec. (0.99 ticks) > INFO: Initializing dual steep norms . . . > INFO: > INFO: Iteration log . . . > INFO: Iteration: 1 Dual objective = 50.568960 > INFO: Iteration: 80 Dual objective = 21147.030405 > INFO: Iteration: 148 Dual objective = 34291.565837 > INFO: Iteration: 210 Dual objective = 36893.251369 > INFO: Removing shift (2). > INFO: Markowitz threshold set to 0.1 > INFO: > INFO: Dual simplex - Optimal: Objective = 3.8997354401e+004 > INFO: Solution time = 0.06 sec. Iterations = 263 (0) > INFO: Deterministic time = 5.57 ticks (88.39 ticks/sec) > > > > _______________________________________________ > Bug-glpk mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/bug-glpk >
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