I use the warm start of Gurobi when solving MILP problems. I don't really understand what the output of the solution means. The following is the log of my optimization problem:
Optimize a model with 193613 rows, 219648 columns and 1727393 nonzeros
Model fingerprint: 0xb9d828e5
Variable types: 137280 continuous, 82368 integer (82368 binary)
Matrix range [1e-01, 1e+03]
Objective range [4e+00, 1e+05]
Bounds range [3e-02, 4e+02]
RHS range [3e-01, 5e+04]
User MIP start did not produce a new incumbent solution
Presolve removed 112027 rows and 113508 columns
Presolve time: 3.82s
Presolved: 81586 rows, 106140 columns, 488233 nonzeros
Variable types: 98753 continuous, 7387 integer (7387 binary)
Deterministic concurrent LP optimizer: primal and dual simplex
Showing first log only...
Root simplex log...
Iteration Objective Primal Inf. Dual Inf. Time
0 2.0250830e+07 3.928851e+04 2.536149e+10 6s
14855 5.2477739e+07 0.000000e+00 1.128216e+06 6s
Concurrent spin time: 0.01s
Solved with dual simplex
Root relaxation: objective 5.042488e+07, 53296 iterations, 3.65 seconds (3.38 work units)
Another try with MIP start
The following is my problem.
- What does "User MIP start did not produce a new incumbent solution” mean?
- What does "Another try with MIP start" mean?
- Why does "Another try with MIP start" appear after "user MIP startup does not produce new existing solution"? How can I understand that the initial point I gave did not produce a feasible solution, but the solution found another good feasible solution based on the information I gave?
Thanks in advance!
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