CPXXgetredlp and CPXgetredlp
The routine CPXXgetredlp/CPXgetredlp returns a pointer for the
presolved problem.
int CPXXgetredlp( CPXCENVptrenv, CPXCLPptrlp, CPXCLPptr *redlp_p )
int CPXgetredlp( CPXCENVptrenv, CPXCLPptrlp, CPXCLPptr *redlp_p )
Description
This is an advanced routine. Advanced routines typically demand a thorough understanding of the algorithms used by CPLEX. Thus they incur a higher risk of incorrect behavior in your application, behavior that can be difficult to debug. Therefore, the team encourages you to consider carefully whether you can accomplish the same task by means of other Callable Library routines instead.
The routine CPXXgetredlp/CPXgetredlp returns a pointer for the
presolved problem. It returns NULL if the problem is not
presolved or if all the columns and rows are removed by presolve. Generally,
the returned pointer may be used only in CPLEX Callable Library query
routines, such as
CPXXsolution and CPXsolution
or
CPXXgetrows and CPXgetrows
.
The presolved problem must not be modified. Any modifications must be
done on the original problem. If the parameter that specifies the
primal and dual reduction type
(CPXPARAM_Preprocessing_Reduce)
is set appropriately, the modifications are automatically carried out on the
presolved problem at the same time. Optimization and query routines can be
used on the presolved problem.
Arguments
- env
-
A pointer to the CPLEX environment, as returned by
CPXXopenCPLEX/CPXopenCPLEX. - lp
-
A pointer to a CPLEX LP problem object, as returned by
CPXXcreateprob/CPXcreateprob. - redlp_p
- A pointer to receive the problem object pointer that results when presolve has been applied to the LP problem object.
Return
The routine returns 0 (zero) if successful and nonzero if an error occurs.Example
status = CPXgetredlp (env, lp, &reducelp);