How do I know the total running time used to get the optimal solution? (Understand the outputs of Gurobi)

Answered

Miranda

• January 14, 2021 05:13

Hello,

I got confused about understanding the outputs of Gurobi. I formulate a problem as a mixed integer program via Gurobi. 

I used the code 'model.optimize()' to find its optimal solution, and I am curious about the total running time that I needed to get the solution.

Should I look at the last value in the 'Time' column in the attached picture (25s)? Or I need to set a timer by myself.

Furthermore, should I expect the 'gap' to be 0 when it reaches the optimal solution? and what is the column before 'Time'?

Thank you.

 

0

• 

  Jaromił Najman

  Gurobi Staff

  • January 14, 2021 11:56
  • Edited

  Hi Miranda,

  The total running time can be seen on the most right column under \(\texttt{Time}\).

  The column before \(\texttt{Time}\) shows the average number of simplex iterations needed in order to solve the continuous relaxation of the printed node.

  The algorithm converges when either MIPGap or MIPGapAbs is reached. The final gap is often lower than the one specified by MIPGap or MIPGapAbs.

  You can find more information in the documentation of MIP Logging.

  Best regards,
  Jaromił

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