All;
I am interfacing GLPK using Fortran 2003 and when solving a MILP problem
using the callback function "cb_func" I am getting the following
assertion error from is_branch_hopeful().
Assertion failed: 1 <= p && p <= T->nslots
Error detected in file ..\src\glpios03.c at line 116
However, when I run with cb_func = NULL as the default GLPK works fine
but I have no callback to interrupt when integer-feasible solutions are
found unfortunately.
When I write out the subproblem index or node number i.e., "p" above
using glp_ios_curr_node(tree)within my callback routine, it correctly
writes out "0" and "1" - see below:
Integer optimization begins...
0
+ 3457: mip = not found yet <= +inf (1; 0)
1
Therefore my only conclusion is that the tree's number of slots i.e.,
"T->nslots" is 0 (zero) for some reason after the call to glp_intopt().
Any assistance on this would be appreciated.
All the best - Jeff
9391 lines were written
GLPK Simplex Optimizer, v4.45
5196 rows, 2942 columns, 14905 non-zeros
Preprocessing...
5194 rows, 2940 columns, 14682 non-zeros
Scaling...
A: min|aij| = 2.500e-002 max|aij| = 1.000e+004 ratio = 4.000e+005
GM: min|aij| = 8.409e-002 max|aij| = 1.189e+001 ratio = 1.414e+002
EQ: min|aij| = 7.071e-003 max|aij| = 1.000e+000 ratio = 1.414e+002
Constructing initial basis...
Size of triangular part = 5174
| 0: obj = 2.865242727e+005 infeas = 0.000e+000 (20)
| 500: obj = 2.355825952e+004 infeas = 5.199e-017 (20)
| 1000: obj = 9.253286000e+003 infeas = 0.000e+000 (20)
| 1233: obj = 9.233624000e+003 infeas = 0.000e+000 (20)
OPTIMAL SOLUTION FOUND
GLPK Integer Optimizer, v4.45
5196 rows, 2942 columns, 14905 non-zeros
1020 integer variables, all of which are binary
Preprocessing...
1500 constraint coefficient(s) were reduced
5194 rows, 2940 columns, 14682 non-zeros
1020 integer variables, all of which are binary
Scaling...
A: min|aij| = 2.500e-002 max|aij| = 1.000e+004 ratio = 4.000e+005
GM: min|aij| = 1.895e-001 max|aij| = 5.277e+000 ratio = 2.785e+001
EQ: min|aij| = 3.647e-002 max|aij| = 1.000e+000 ratio = 2.742e+001
2N: min|aij| = 3.125e-002 max|aij| = 1.328e+000 ratio = 4.250e+001
Constructing initial basis...
Size of triangular part = 5174
Solving LP relaxation...
GLPK Simplex Optimizer, v4.45
5194 rows, 2940 columns, 14682 non-zeros
* 1233: obj = 0.000000000e+000 infeas = 0.000e+000 (20)
* 1500: obj = 0.000000000e+000 infeas = 0.000e+000 (20)
* 2000: obj = 0.000000000e+000 infeas = 0.000e+000 (20)
* 2500: obj = 6.607216557e+003 infeas = 5.418e-014 (20)
* 3000: obj = 8.950690939e+003 infeas = 2.364e-013 (19)
Warning: numerical instability (primal simplex, phase II)
3353: obj = 9.183802165e+003 infeas = 4.355e-002 (18)
* 3354: obj = 9.183802181e+003 infeas = 1.213e-008 (18)
Warning: numerical instability (primal simplex, phase II)
3356: obj = 9.183802165e+003 infeas = 4.355e-002 (18)
* 3357: obj = 9.183802181e+003 infeas = 2.128e-014 (18)
* 3457: obj = 9.183903910e+003 infeas = 2.266e-013 (18)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
0
+ 3457: mip = not found yet <= +inf (1; 0)
1
Assertion failed: 1 <= p && p <= T->nslots
Error detected in file ..\src\glpios03.c at line 116
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