Why binary variables range from (0,1)

Answered

Chenshi Jia

• November 23, 2023 09:19

Hi,

I set the variables as binary. But while adding lazy constraints, some values of variables range from (0,1). Please suggest.

var = m.addVars(dist.keys(), vtype=GRB.BINARY, name='e')

0

• 

  Chenshi Jia

  • November 23, 2023 09:22

  

  

  

  Some pictures are missing.

  0
• 

  Michel Soares

  • November 23, 2023 11:13

  

  

  Hi Chenshi,

  I assume you might be referring to some of these 0.9999999 numbers. Indeed there are some "rounding errors" that may cause this behaviour (usually quite small, less than 1e-5).

  When checking whether a binary value is 0 or 1, you should consider a possible error, doing something like:

  if binary_value > 0.5:
   #assume binary is 1
  else:
   #assume binary is 0

  1
• 

  Chenshi Jia

  • November 23, 2023 11:19

  

  

  Thank you！

  0
• 

  Riley Clement

  Gurobi Staff

  • November 23, 2023 21:42

  Note we have a parameter, IntegralityFocus, that can help with this but it incurs a (typically small) cost in performance.

  0

Please sign in to leave a comment.