Skip to main content

Maximum number of elements in LineExp for free trial?

Answered

Comments

7 comments

  • Official comment
    Simranjit Kaur
    • Gurobi Staff Gurobi Staff
    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 Gurobi Staff

    Hi Huib,

    For quadratic problems, the limited-size pip license allows for only 200 variables, see How do I resolve an "Model too large for size-limited Gurobi license" error?

    If you are an academic, you can get a free academic license which does not hold the size limitation.

    If you are a commercial user, you can apply for a free trial.

    In any case, when applying for a license, please use either an email connected to your university or your company.

    Best regards,
    Jaromił

    0
  • Huib Meulenbelt
    • Gurobi-versary
    • Curious
    • Conversationalist

    Hi Jaromił,

    Thanks for responding! I noticed the limits in the documentation, yes. But I am not sure why my model violates them? There are no quadratic terms in my model I believe.

    Can you check what's going on?

    0
  • Jaromił Najman
    • Gurobi Staff Gurobi Staff

    Hi Huib,

    The constraint

    p_bust_var * p_bust_var_div == 1

    is a quadratic one because \(\texttt{p_bust_var}\) and \(\texttt{p_bust_var_div}\) are both optimization variables.

    Best regards,
    Jaromił

    0
  • Huib Meulenbelt
    • Gurobi-versary
    • Curious
    • Conversationalist

    Gotcha. I included that constraint based on your article. Later in the script I need to divided a term by p_bust_var. Is there any other way to satisfy the vars limitations and divide by p_bust_var?

    0
  • Huib Meulenbelt
    • Gurobi-versary
    • Curious
    • Conversationalist

    Both constraints are expressed in the form of p_bust_var so I can write 

    m.addConstr(p_bust_var_div == 1 / (1 - gurobi.quicksum(p_vars)))

    Then I don't have a quadratic model anymore correct. However, this yields the following error. 

    GurobiError: Divisor must be a constant

    Still the division problem, any tips?

    0
  • Jaromił Najman
    • Gurobi Staff Gurobi Staff

    Hi Huib,

    Unfortunately, there is no way to avoid using bilinear terms when trying to reformulate division. However, you could use a piecewise-linear approximation of the function.

    Best regards,
    Jaromił

    0

Post is closed for comments.