VBasis/CBasis get and set

回答済み

Thomas Schlechte

2023年02月21日 10:26 編集済み

• 
• 
• 

I am a little confused that when getting the LP basis in python, you have to

self.model.getAttr("VBasis", self.model.getVars())

but for setting you have to do something like this:

        for var in self.model.getVars():
            var.setAttr("VBasis", vBasis[var.index])

Am I right or did I just not found the corresponding method?

Wouldn't it be good to have also a Wrapper like:

 model.setAttr("VBasis",..)

Thanks a lot

Thomas

関連

• Attribute
• Warm Start

1

• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2026年11月13日 01:48

  This post is more than two 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 try Gurobot, our chatbot interface offering instant, expert-level support.
• 

  Marika Karbstein

  • Gurobi Staff

  2023年02月21日 13:00

  Hi Thomas,

  The function Model.setAttr() already exists.

  Cheers,
  Marika

  -1
• 

  Thomas Schlechte

  2023年02月21日 14:19 編集済み

  • 
  • 
  • 

  Hi Marika,

  ah okay, I did not see the call with 3 arguments. So it should work like this

  // solve
  ...
  vBasis = self.model.getAttr("VBasis", self.model.getVars())
  cBasis = self.model.getAttr("CBasis", self.model.getConstrs())
  
  // do for example a problem specific RENS 
  ...
  
  // set lp solution
  self.model.setAttr("VBasis", model.getVars(), vBasis)
  self.model.setAttr("CBasis", model.getConstr(), cBasis)

  Thanks

  Thomas

   

  1
• 

  noah smith

  2024年06月19日 05:45

  • 
  • 

  Hi, Thomas's second comment here is very useful. Could highly recommend that his code-snippet, or something like it, be included in discussions of lp warm start. A simple 'hello world style' example model doing this would also be useful. Multiple examples of warm start would be helpful.

  Concrete 'how to' with examples that pop up when googling 'gurobi warm start'.

  Understood this stuff is apparently totally obvious for gurobi employees.

  It's not for every gurobi user, have learned that the hard way over the last few days.

  Thanks

  Noah

   

  0
• 

  Gwyneth Butera

  • Gurobi Staff

  2024年06月19日 11:45

  Thanks for the suggestion Noah! I have added this to my list of potential improvements for the Knowledge Base. -G

  1

投稿コメントは受け付けていません。