Topic
  • 2 replies
  • Latest Post - ‏2013-02-05T17:58:01Z by alvarolorca
alvarolorca
alvarolorca
21 Posts

Pinned topic Problem with "Dual infeasible due to empty column"

‏2013-02-05T15:58:18Z |
Hi, in a simple problem I am getting "Dual infeasible due to empty column 'theta.10'." Yet, when I check for this column using "linear_constraints.get_coefficients", right before solving, I can clearly see that the column has several ones.

Where might be my error?

Many thanks,

Alvaro
Updated on 2013-02-05T17:58:01Z at 2013-02-05T17:58:01Z by alvarolorca
  • SystemAdmin
    SystemAdmin
    7929 Posts

    Re: Problem with "Dual infeasible due to empty column"

    ‏2013-02-05T16:32:15Z  
    The column may be empty after presolve. What happens if you disable presolve (set CPX_PARAM_PREIND to 0)?
  • alvarolorca
    alvarolorca
    21 Posts

    Re: Problem with "Dual infeasible due to empty column"

    ‏2013-02-05T17:58:01Z  
    That solved it, thank you Daniel.

    I think the message is confusing, it would be nice if it specified that a reduction of the problem had an infeasible dual (but it is really great how fast you answered with the right approach).

    Alvaro