How do I model if and only if statements in Gurobi

回答済み

Anggita Ketlin Bella Pratiwi

2024年03月26日 06:47

• 
• 
• 

hii, I'm having trouble modeling if and only if statements. I modeled it like the code below

for i in range(I): 
    for j in range(J): 
        m.addConstr((h[j] + eps - M * ( 1 - b) <= g[i]), "bigM_constr1" ) 
        m.addConstr((h[j] + M * b >= g[i]), "bigM_constr2" ) 
        '''
        m.addConstr((b==1) >> (x[i,j] == 1), "indicator_constr1")         
        m.addConstr((b==0) >> (x[i,j] == 0), "indicator_constr2")
        '''
        m.addGenConstrIndicator(b,True , x[i,j], GRB.EQUAL, 1.0)

Why when I run it there is an errorKey : (0.9) ?
Please help me

関連

• KeyError
• Indicator Constraints

0

• 正式なコメント

  

  Simranjit Kaur

  • Gurobi Staff

  2026年11月13日 01:27

  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.
• 

  Jaromił Najman

  • Gurobi Staff

  2024年03月26日 08:16

  Hi Anggita,

  We discuss how to debug a key error in the Knowledge Base article Tutorial: Preparing a Minimal Reproducible Example.

  Best regards, 
  Jaromił

  0
• 

  Anggita Ketlin Bella Pratiwi

  2024年03月26日 14:27

  • 
  • 
  • 

  Hi, I want to ask more. To describe conditional statements whether there are additional indicator limits besides this

  m.addConstr((b == 1 ) >> (z == w1), name= "indicator_constr1" )
  m.addConstr((b == 0 ) >> (z == w2), nama= "indicator_constr2" )

  0
• 

  Jaromił Najman

  • Gurobi Staff

  2024年03月26日 14:35

  To describe conditional statements whether there are additional indicator limits besides this

  Could you elaborate what exactly you mean by "additional indicator limits"?

  Maybe the Knowledge Base article How do I model conditional statements in Gurobi? can help.

  0

投稿コメントは受け付けていません。