[Clp] Possible Degeneracy or bug?

[Raghavendra Hosur]

Hi, I am relatively new at using Clp, so please forgive my ignorance.
I am using ClpSimplex (primal) to solve a series of independent lps but
frequently I end up with such an output, where even though the objective
doesn't seem to change, the algorithm doesn't terminate. I wanted to know if
this implies that the problem is degenerate, or something is wrong with my
implementation.

There are other instances where the lp finishes correctly to optimal
solutions.

Any help would be greatly appreciated. Thanks!

Raghu

Clp0006I 406  Obj 772649 Primal inf 0.000126728 (732) Dual inf 0.00268515
(4)
Clp0006I 408  Obj 772678 Primal inf 0.000126819 (731) Dual inf 0.0260005 (5)
Clp0006I 408  Obj 772678 Primal inf 0.000126819 (731)
Clp0001I Primal infeasible - objective value 772678
Clp0034I Pass 20 took 408 iterations, objective 772678, dual infeasibilities
3.20959e+14( 104734)
Clp0006I 0  Obj 21928.6 Dual inf 1.53563e+09 (93726)
Clp0006I 286  Obj 21928.6 Dual inf 6.28598e+08 (103375)
Clp0006I 572  Obj 21928.6 Dual inf 6.28153e+08 (109279)
Clp0006I 858  Obj 21928.6 Dual inf 7.51938e+08 (104946)
Clp0006I 1144  Obj 21928.6 Primal inf 1.5198e-06 (88) Dual inf 1.61512e+16
(110739)
Clp0006I 1430  Obj 21928.6 Primal inf 2.99672e-06 (89) Dual inf 1.44544e+16
(107683)
Clp0006I 1716  Obj 21928.6 Primal inf 7.03824e-06 (186) Dual inf 2.88028e+16
(108821)
Clp0006I 2002  Obj 21928.6 Primal inf 4.1197e-06 (172) Dual inf 2.78488e+16
(110344)
Clp0006I 2288  Obj 21928.6 Primal inf 3.97076e-06 (142) Dual inf 1.97809e+16
(104632)
Clp0006I 2574  Obj 21928.6 Primal inf 1.06905e-05 (310) Dual inf 5.24583e+16
(105880)
Clp0006I 2860  Obj 21928.6 Primal inf 3.09492e-05 (522) Dual inf 1.25178e+17
(111335)
Clp0006I 3146  Obj 21928.6 Primal inf 7.71531e-06 (233) Dual inf 3.12771e+16
(110374)
Clp0006I 3432  Obj 21928.6 Primal inf 1.22927e-06 (64) Dual inf 8.1049e+15
(111837)
Clp0006I 3718  Obj 21928.6 Primal inf 8.62081e-06 (364) Dual inf 4.23991e+16
(116000)
Clp0006I 4004  Obj 21928.6 Primal inf 1.58615e-05 (400) Dual inf 3.78093e+16
(111921)
Clp0006I 4290  Obj 21928.6 Primal inf 3.96591e-05 (703) Dual inf 1.00593e+17
(114464)
Clp0006I 4576  Obj 21928.6 Primal inf 9.574e-06 (278) Dual inf 9.14069e+16
(116026)
Clp0006I 4862  Obj 21928.6 Primal inf 5.37831e-06 (177) Dual inf 2.07954e+16
(117461)
Clp0006I 5148  Obj 21928.6 Primal inf 1.72535e-05 (398) Dual inf 1.38148e+17
(112503)
Clp0006I 5434  Obj 21928.6 Primal inf 3.70437e-06 (170) Dual inf 3.62376e+16
(114824)
Clp0006I 5720  Obj 21928.6 Primal inf 2.0438e-05 (466) Dual inf 1.08007e+17
(121401)
Clp0006I 6006  Obj 21928.6 Primal inf 2.46369e-06 (109) Dual inf 1.72894e+16
(119026)
Clp0006I 6292  Obj 21928.6 Primal inf 1.10956e-05 (317) Dual inf 4.72236e+16
(120515)
Clp0006I 6578  Obj 21928.6 Primal inf 7.21757e-06 (248) Dual inf 2.81586e+16
(114879)
Clp0006I 6864  Obj 21928.6 Primal inf 4.36313e-05 (751) Dual inf 1.3996e+17
(120410)
Clp0006I 7150  Obj 21928.6 Primal inf 8.52594e-06 (290) Dual inf 8.37034e+16
(123574)
Clp0006I 7436  Obj 21928.6 Primal inf 3.17695e-05 (567) Dual inf 1.22288e+17
(119391)
Clp0006I 7722  Obj 21928.6 Primal inf 5.04181e-06 (177) Dual inf 3.21725e+16
(118725)
Clp0006I 8008  Obj 21928.6 Primal inf 9.49529e-06 (261) Dual inf 3.26279e+16
(123801)
Clp0006I 8294  Obj 21928.6 Primal inf 5.12685e-06 (224) Dual inf 2.84582e+16
(122091)
Clp0006I 8580  Obj 21928.6 Primal inf 3.21936e-05 (614) Dual inf 1.32448e+17
(122134)
Clp0006I 8866  Obj 21928.6 Primal inf 2.0372e-05 (422) Dual inf 1.14913e+17
(118697)
Clp0006I 9152  Obj 21928.6 Primal inf 1.17878e-05 (341) Dual inf 6.88182e+16
(120097)
Clp0006I 9438  Obj 21928.6 Primal inf 1.29273e-05 (339) Dual inf 5.48133e+16
(129122)
Clp0006I 9724  Obj 21928.6 Primal inf 3.44663e-05 (632) Dual inf 1.1567e+17
(120420)
Clp0006I 10010  Obj 21928.6 Primal inf 1.68309e-05 (433) Dual inf
9.41341e+16 (121109)
Clp0006I 10296  Obj 21928.6 Primal inf 2.72704e-05 (588) Dual inf
1.42313e+17 (123832)
Clp0006I 10582  Obj 21928.6 Primal inf 1.52432e-05 (422) Dual inf
1.03183e+17 (116874)
Clp0006I 10868  Obj 21928.6 Primal inf 6.48892e-06 (251) Dual inf
2.73216e+16 (120148)
Clp0006I 11154  Obj 21928.6 Primal inf 2.62665e-05 (555) Dual inf
9.66086e+16 (119815)
Clp0006I 11440  Obj 21928.6 Primal inf 5.69419e-05 (808) Dual inf
1.89219e+17 (125062)
Clp0006I 11726  Obj 21928.6 Primal inf 3.29175e-05 (617) Dual inf
1.78859e+17 (123929)
Clp0006I 12012  Obj 21928.6 Primal inf 2.36275e-05 (558) Dual inf
7.27947e+16 (119947)
Clp0006I 12298  Obj 21928.6 Primal inf 4.79747e-06 (180) Dual inf
2.71587e+16 (121841)
Clp0006I 12584  Obj 21928.6 Primal inf 5.91471e-06 (238) Dual inf 4.9516e+16
(122346)
Clp0006I 12870  Obj 21928.6 Primal inf 1.57108e-05 (423) Dual inf
6.34562e+16 (123919)
Clp0006I 13156  Obj 21928.6 Primal inf 1.14551e-05 (272) Dual inf
7.11369e+16 (125086)
Clp0006I 13442  Obj 21928.6 Primal inf 1.90404e-05 (426) Dual inf 1.5706e+17
(124454)
Clp0006I 13728  Obj 21928.6 Primal inf 1.82882e-05 (436) Dual inf 1.7584e+17
(121187)
Clp0006I 14014  Obj 21928.6 Primal inf 1.17483e-05 (320) Dual inf
4.74952e+16 (125373)
Clp0006I 14300  Obj 21928.6 Primal inf 3.00133e-05 (599) Dual inf
1.33231e+17 (125045)
Clp0006I 14586  Obj 21928.6 Primal inf 3.60458e-05 (658) Dual inf
1.57479e+17 (122796)
Clp0006I 14872  Obj 21928.6 Primal inf 4.39828e-06 (154) Dual inf
2.39899e+16 (128197)
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