Hello All
I posed the question if it is possible to add cuts to an MILP model only at the root node when using CPLEX as the solver.
There is an option that allows this, but the option is not public. IBM communicated the option to me, together with the information of how to use it. However, I don’t know how to pass it to the solver when using GAMS.
Is there a way to pass hidden options through the option file “cplex.opt” to CPLEX?
Thank you in advance for your answer.
There is a way to do that. You need the CPLEX internal number for the parameter you want to set and the type (most likely it is an integer or real valued type). Then you write into your cplex.opt the following line “secret internalNumber type value”. For type use ‘i’ for integer and ‘r’ for real valued options, e.g.
secret 1158 i 0
turns off sifting (which can also set by a regular option). You can verify that the option setting worked because (recent versions of Cplex) echo the non-default parameters to the log and you see for this example “CPXPARAM_Sifting_Simplex 0”
-Michael