[Help-glpk] long-step dual ratio test in glpk 4.60

[Andrew Makhorin]

The effect of the long-step dual ratio test (--flip):

GLPSOL: GLPK LP/MIP Solver, v4.60
Parameter(s) specified in the command line:
 ken-11.mps --dual --log 1.log
Reading problem data from 'ken-11.mps'...
Problem: KEN-11
Objective: COST
14695 rows, 21349 columns, 70354 non-zeros
102733 records were read
Free objective row was removed
GLPK Simplex Optimizer, v4.60
14694 rows, 21349 columns, 49058 non-zeros
Preprocessing...
10085 rows, 16698 columns, 38478 non-zeros
Scaling...
 A: min|aij| =  1.000e+00  max|aij| =  1.000e+00  ratio =  1.000e+00
Problem data seem to be well scaled
Constructing initial basis...
Size of triangular part is 9964
#     0: obj =  -7.850959808e+11 inf =   0.000e+00 (5144)
#   500: obj =  -6.033485012e+11 inf =   0.000e+00 (5143)
#  1000: obj =  -5.210805806e+11 inf =   0.000e+00 (5034) 1
#  1500: obj =  -4.544973698e+11 inf =   0.000e+00 (4841)
#  2000: obj =  -4.047986374e+11 inf =   0.000e+00 (4843)
#  2500: obj =  -3.610652042e+11 inf =   0.000e+00 (4738) 2
#  3000: obj =  -3.051471536e+11 inf =   0.000e+00 (4731) 2
#  3500: obj =  -2.801224966e+11 inf =   0.000e+00 (4763) 1
#  4000: obj =  -2.484477159e+11 inf =   0.000e+00 (4697) 2
#  4500: obj =  -2.271060241e+11 inf =   0.000e+00 (4599) 1
#  5000: obj =  -1.854208838e+11 inf =   0.000e+00 (4469) 2
#  5500: obj =  -1.645649787e+11 inf =   0.000e+00 (4476)
#  6000: obj =  -1.381708107e+11 inf =   0.000e+00 (4433) 2
#  6500: obj =  -1.218201131e+11 inf =   0.000e+00 (4390) 1
#  7000: obj =  -1.034663745e+11 inf =   0.000e+00 (4400) 2
#  7500: obj =  -9.226747568e+10 inf =   0.000e+00 (4441) 1
#  8000: obj =  -1.157195921e+10 inf =   0.000e+00 (4057) 2
#  8500: obj =  -1.022607116e+10 inf =   0.000e+00 (4043) 1
#  9000: obj =  -9.346081379e+09 inf =   0.000e+00 (4009) 1
#  9500: obj =  -8.742435823e+09 inf =   0.000e+00 (3997) 1
# 10000: obj =  -8.303107367e+09 inf =   0.000e+00 (4018) 2
# 10500: obj =  -7.998977451e+09 inf =   0.000e+00 (4067) 1
# 11000: obj =  -7.794416433e+09 inf =   0.000e+00 (4125) 2
# 11500: obj =  -7.683266368e+09 inf =   0.000e+00 (4078) 2
# 12000: obj =  -7.586833935e+09 inf =   0.000e+00 (3942) 3
# 12500: obj =  -7.527099754e+09 inf =   0.000e+00 (3833) 2
# 13000: obj =  -7.454465857e+09 inf =   0.000e+00 (3621) 4
# 13500: obj =  -7.403094096e+09 inf =   0.000e+00 (3435) 2
# 14000: obj =  -7.327048949e+09 inf =   0.000e+00 (3285) 5
# 14500: obj =  -7.295449479e+09 inf =   0.000e+00 (3173) 3
# 15000: obj =  -7.243464193e+09 inf =   0.000e+00 (2924) 4
# 15500: obj =  -7.219276764e+09 inf =   0.000e+00 (2780) 4
# 16000: obj =  -7.172433148e+09 inf =   0.000e+00 (2526) 5
# 16500: obj =  -7.156365754e+09 inf =   0.000e+00 (2319) 4
# 17000: obj =  -7.124272876e+09 inf =   0.000e+00 (2064) 5
# 17500: obj =  -7.078089674e+09 inf =   0.000e+00 (1734) 4
# 18000: obj =  -7.030743265e+09 inf =   0.000e+00 (1291) 4
# 18500: obj =  -7.000185914e+09 inf =   0.000e+00 (945) 4
# 19000: obj =  -6.976593012e+09 inf =   0.000e+00 (400) 4
# 19347: obj =  -6.972382263e+09 inf =   2.956e-12 (0) 3
OPTIMAL LP SOLUTION FOUND
Time used:   64.1 secs
Memory used: 17.3 Mb (18118733 bytes)

GLPSOL: GLPK LP/MIP Solver, v4.60
Parameter(s) specified in the command line:
 ken-11.mps --flip --log 2.log
Reading problem data from 'ken-11.mps'...
Problem: KEN-11
Objective: COST
14695 rows, 21349 columns, 70354 non-zeros
102733 records were read
Free objective row was removed
GLPK Simplex Optimizer, v4.60
14694 rows, 21349 columns, 49058 non-zeros
Preprocessing...
10085 rows, 16698 columns, 38478 non-zeros
Scaling...
 A: min|aij| =  1.000e+00  max|aij| =  1.000e+00  ratio =  1.000e+00
Problem data seem to be well scaled
Constructing initial basis...
Size of triangular part is 9964
#     0: obj =  -7.850959808e+11 inf =   0.000e+00 (5144)   0,0
#   500: obj =  -4.468895228e+10 inf =   0.000e+00 (3819) 3   56,444
#  1000: obj =  -7.829111335e+09 inf =   0.000e+00 (3840) 5   18,482
#  1500: obj =  -7.352943572e+09 inf =   0.000e+00 (3287) 4   0,500
#  2000: obj =  -7.209374552e+09 inf =   0.000e+00 (2836) 4   1,499
#  2500: obj =  -7.122869032e+09 inf =   0.000e+00 (2284) 4   1,499
#  3000: obj =  -7.065503221e+09 inf =   0.000e+00 (1805) 3   43,457
#  3500: obj =  -7.039036714e+09 inf =   0.000e+00 (1380) 4   34,466
#  4000: obj =  -7.003560830e+09 inf =   0.000e+00 (1014) 3   79,421
#  4500: obj =  -6.983172990e+09 inf =   0.000e+00 (585) 4   100,400
#  5000: obj =  -6.972418055e+09 inf =   0.000e+00 (27) 5   70,430
#  5026: obj =  -6.972382263e+09 inf =   2.274e-12 (0)   0,26
OPTIMAL LP SOLUTION FOUND
Time used:   16.2 secs
Memory used: 17.4 Mb (18281397 bytes)