More digits in log file

Answered

Noortje Bonenkamp

• May 07, 2020 14:10

Dear all, 

I am creating plots of the evolution of the upper and lower bound of  the objective function for a MILP, where I use gurobi to generate these. 

When I create a logfile, either .log, .txt or .csv, it seems that values are rounded to 4 decimals in the file, and that I cannot retrieve the original values (only from the Python console directly). Is there a way to print these in a logfile with more decimals? My model is programmed in Pyomo. 

Best regards,

Noortje

 

 

    Nodes    |    Current Node    |     Objective Bounds      |     Work

 Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time


0 0 2.5500e+08 0 194 3.2154e+08 2.5500e+08 20.7% - 1s

0 0 2.5502e+08 0 193 3.2154e+08 2.5502e+08 20.7% - 1s

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• 

  Eli Towle

  Gurobi Staff

  • May 07, 2020 16:06

  Hi Noortje,

  There unfortunately isn't a way to increase the log precision like this. However, you can retrieve these lower and upper bounds programmatically with the \(\texttt{MIPNODE_OBJBST}\) and \(\texttt{MIPNODE_OBJBND}\) callbacks (see here). This should make plotting much easier, since you won't have to spend time extracting these values from the log. Pyomo is a third-party API, but I believe they support callbacks like this.

  Thanks,

  Eli

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• 

  Noortje Bonenkamp

  • May 07, 2020 18:05

  

  

  

  Thank you, Eli! I will try it like this! 

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