MIP callback switch between original model and reduced, presolved model
Controls whether your callback accesses node information of the original model (off) or node information of the reduced, presolved model (on, default).
Purpose
MIP callback switch between original model and reduced, presolved model
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Description
Controls whether your callback accesses node information of the original model (off) or node information of the reduced, presolved model (on, default); also known as the MIP callback reduced LP parameter.
Advanced routines to control
MIP callbacks (such as CPXgetcallbacklp , CPXsetheuristiccallbackfunc , CPXsetbranchcallbackfunc , CPXgetbranchcallbackfunc , CPXsetcutcallbackfunc , CPXsetincumbentcallbackfunc , CPXgetcallbacksosinfo , CPXcutcallbackadd , CPXcutcallbackaddlocal ,
and others) consider the setting of this parameter and access the
original model or the reduced, presolved model accordingly.
The
routine CPXgetcallbacknodelp is an exception: it
always accesses the current node LP associated with the presolved
model, regardless of the setting of this parameter.
For certain
routines, such as CPXcutcallbackadd , when you set
the parameter CPX_PARAM_MIPCBREDLP to zero, you should
also set CPX_PARAM_PRELINEAR to zero as well.
In the C++, Java, .NET, Python, and MATLAB APIs of CPLEX, only the original model is available to callbacks. In other words, this parameter is effective only for certain advanced routines of the C API.
| Value | Symbol | Meaning |
|---|---|---|
| 0 | CPX_OFF |
Off: use original model |
| 1 | CPX_ON |
On: use reduced, presolved model; default |