Do not print "Set parameter Username" in console

Answered

Allyson Silva

December 02, 2021 15:46

• 
• 
• 

I am using the C++ API and recently updated my Gurobi version from 9.1 to 9.5. It seems there is a new feature that prints "Set parameter XXX" when a parameter is manually set in the new version. I have been using Gurobi to solve an optimization problem that requires calling new environments multiple times sequentially. As so, I don't want to print anything from Gurobi in my console to keep it clean. I followed the second suggestion in this nice post to suppress all console output. However, even when setting OutputFlag 0 in an external file, the console still prints "Set parameter Username" after every new environment creation. How can I suppress that?

Related to

• Log Files

0

• Official comment

  

  Simranjit Kaur

  • Gurobi Staff

  December 06, 2024 00:22

  This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.
• 

  Jaromił Najman

  • Gurobi Staff

  December 02, 2021 16:02

  In order to suppress the "Set parameter XXX" output, you have to set the parameter OutputFlag as the first parameter in your environment, i.e., 

  // Create an environment
  GRBEnv env = GRBEnv(true);
  env.set(GRB_IntParam_OutputFlag,0);
  // Rest of your code

  Best regards,
  Jaromił

  1
• 

  Allyson Silva

  December 03, 2021 02:55

  • 
  • 
  • 

  Thanks for the quick answer, Jaromił!
  
  In fact, my problem is that I am creating the GRBEnv and GRBModel as attributes of a class as:

  class MyProblem {
    public:
      GRBEnv env;
      GRBModel model = GRBModel(env);
      // ...
      void setModel();
  }

  and adding model.set(GRB_IntParam_OutputFlag, 0) as the first command in void setModel(). After your suggestion, I could contour the problem by adding a constructor to initialize env before model as:

  class MyProblem {
    public:
      GRBEnv env;
      GRBModel model;
  
      // Constructor to set OutputFlag before creating my model
      MyProblem() : env(true), model(createModel(env)) {};
  
      GRBModel createModel(GRBEnv& env);
      void setModel();
  }
  
  // Set OutputFlag to 0 in env
  GRBModel MyProblem::createModel(GRBEnv& env) {
    env.set(GRB_IntParam_OutputFlag, 0);
    env.start();
    return GRBModel(env);
  }

  I will leave this here in case it may be helpful to someone else.

  1
• 

  Florian Götz

  March 03, 2023 11:13

  • 
  • 
  • 

  Hello,

  could someone please post a solution for python users?

  Thanks a lot.

  0
• 

  Jaromił Najman

  • Gurobi Staff

  March 03, 2023 12:18

  could someone please post a solution for python users?

  The Python solution can be found in the Knowledge Base article How do I suppress all console output from Gurobi?

  -1

Post is closed for comments.