• Gurobi Staff

Hi Gleb,

Could you post the simple quadratic model, such that we can try to reproduce this issue? If possible, please post a small self-contained code.

Best regards,
Jaromił

Hi Jaromił,

the instance (recognized as convex quadratic, despite the equality) is this:

MaximizeobjSubject Top_times_0: - obj + [ x ^2 ] = 0Boundsx <= 10obj <= 100End

When I call gurobi_cl ResultFile=result.json instance.lp, the json result file contains

{ "SolutionInfo": { "Status": 2, "Runtime": "3.2305717468261719e-04", "ObjVal": "100", "BoundVio": "0", "ConstrVio": "0", "IterCount": "0", "BarIterCount": 0}}

i.e., ObjBound(C) are not there. For a slightly more complicated instance, which is also solved at root but at least requires 1 iteration of barrier, the bounds are there. I am happy to write C code but I think this shows the issue (if it is not the intended behaviour, but the documentation says nothing except that the attributes are intended for MIPs).

Cheers, Gleb

• Gurobi Staff

Hi Gleb,

Thanks for posting the example. The ObjBoundC attribute is not available since your model is not a MIP. If you change the type of one of your variables to integer, Gurobi will compute the ObjBoundC.

Best regards
Silke