Re: [Bug-glpk] Fwd: bug in GLPK 4.17

[Andrew Makhorin]

> I'm sorry, I think I did'nt send you the correct files. The problem is
> with eq.lp.

> Alain

> -------- Forwarded Message --------
> From: Alain Poirier <address@hidden>
> To: address@hidden
> Subject: bug in GLPK 4.17
> Date: Wed, 12 Sep 2007 13:00:36 -0400
> Hello,

> Here's a problem which GLPK 4.17 can't solve. I join the log. If I
> change a certain data 31.00 by 31.01, then it works. You find 31.00 in
> the constraint named cDemDef_1. In fact, if I put >= 31 in cDemDef_1
> instead of = 31, then it works. It should give the same result.

Alain,

I cannot reproduce the error. I solved both your instances with glpsol
4.20, and there were no problems; please see the log below.

Which options did you pass to glpsol?

lpx_read_cpxlp: reading problem data from `eq.lp'...
eq.lp:5523: warning: lower bound of variable `x#976#1' redefined
eq.lp:5523: warning: upper bound of variable `x#976#1' redefined
eq.lp:5524: warning: lower bound of variable `x#976#2' redefined
. . .
lpx_read_cpxlp: 2188 rows, 873 columns, 6120 non-zeros
lpx_read_cpxlp: 94 integer columns, all of which are binary
lpx_read_cpxlp: 5617 lines were read
glp_simplex: original LP has 2188 rows, 873 columns, 6120 non-zeros
glp_simplex: presolved LP has 2141 rows, 836 columns, 5535 non-zeros
lpx_adv_basis: size of triangular part = 2141
      0:   objval =   3.491300000e+02   infeas =   1.000000000e+00 (0)
      1:   objval =   3.645800000e+02   infeas =   2.710505431e-17 (0)
*     1:   objval =   3.645800000e+02   infeas =   2.439454888e-16 (0)
*   200:   objval =   1.991791190e+02   infeas =   1.429583184e-14 (0)
*   233:   objval =   9.833899991e+01   infeas =   1.079313429e-13 (0)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
+   233: mip =     not found yet >=              -inf        (1; 0)
+   515: mip =   3.186880000e+02 >=   9.833899991e+01  69.1% (20; 0)
+   641: mip =   2.577000000e+02 >=   9.833899991e+01  61.8% (27; 1)
+   759: mip =   1.992000000e+02 >=   9.833899991e+01  50.6% (27; 6)
+  1092: mip =   1.892000000e+02 >=   9.833899991e+01  48.0% (32; 10)
+  1121: mip =   1.527000000e+02 >=   9.833899991e+01  35.6% (27; 19)
+  1712: mip =   1.413000000e+02 >=   1.089965282e+02  22.9% (26; 42)
+  3149: mip =   1.413000000e+02 >=     tree is empty   0.0% (0; 165)
INTEGER OPTIMAL SOLUTION FOUND
Time used:   8.0 secs
Memory used: 2.0 Mb (2111532 bytes)

lpx_read_cpxlp: reading problem data from `geq.lp'...
geq.lp:5523: warning: lower bound of variable `x#976#1' redefined
geq.lp:5523: warning: upper bound of variable `x#976#1' redefined
geq.lp:5524: warning: lower bound of variable `x#976#2' redefined
. . .
lpx_read_cpxlp: 2188 rows, 873 columns, 6120 non-zeros
lpx_read_cpxlp: 94 integer columns, all of which are binary
lpx_read_cpxlp: 5617 lines were read
glp_simplex: original LP has 2188 rows, 873 columns, 6120 non-zeros
glp_simplex: presolved LP has 2141 rows, 836 columns, 5535 non-zeros
lpx_adv_basis: size of triangular part = 2141
      0:   objval =   7.270000000e+01   infeas =   1.000000000e+00 (0)
    200:   objval =   1.021154872e+02   infeas =   3.962713690e-01 (0)
    334:   objval =   2.437013482e+02   infeas =   1.733510153e-19 (0)
*   334:   objval =   2.437013482e+02   infeas =   1.993952718e-16 (0)
*   400:   objval =   1.128595837e+02   infeas =   1.613169103e-13 (0)
*   600:   objval =   9.943384066e+01   infeas =   1.967832078e-17 (0)
*   624:   objval =   9.833899991e+01   infeas =   3.553303214e-19 (0)
OPTIMAL SOLUTION FOUND
Integer optimization begins...
+   624: mip =     not found yet >=              -inf        (1; 0)
+   848: mip =   5.336880000e+02 >=   9.833899991e+01  81.6% (16; 0)
+   857: mip =   4.136880000e+02 >=   9.833899991e+01  76.2% (17; 1)
+  1092: mip =   2.942000000e+02 >=   9.833899991e+01  66.6% (19; 5)
+  1224: mip =   2.777000000e+02 >=   9.833899991e+01  64.6% (18; 14)
+  1230: mip =   2.177000000e+02 >=   9.833899991e+01  54.8% (18; 15)
+  1466: mip =   1.992000000e+02 >=   9.833899991e+01  50.6% (20; 19)
+  1774: mip =   1.577000000e+02 >=   9.833899991e+01  37.6% (22; 22)
+  1938: mip =   1.527000000e+02 >=   1.066349572e+02  30.2% (17; 35)
+  2600: mip =   1.513000000e+02 >=   1.089965282e+02  28.0% (27; 68)
+  3754: mip =   1.463000000e+02 >=   1.269182892e+02  13.2% (20; 133)
+  4058: mip =   1.413000000e+02 >=   1.269182892e+02  10.2% (17; 152)
+  4967: mip =   1.413000000e+02 >=     tree is empty   0.0% (0; 261)
INTEGER OPTIMAL SOLUTION FOUND
Time used:   12.0 secs
Memory used: 2.0 Mb (2111532 bytes)