CPXbasicpresolve

Note

This is an advanced routine. Advanced routines typically demand a profound understanding of the algorithms used by ILOG CPLEX. Thus they incur a higher risk of incorrect behavior in your application, behavior that can be difficult to debug. Therefore, ILOG encourages you to consider carefully whether you can accomplish the same task by means of other Callable Library routines instead.

The routine CPXbasicpresolve performs bound strengthening and detects redundant rows. CPXbasicpresolve does not create a presolved problem. This routine cannot be used for quadratic programs.

Values for rstat[i]:

0 if row i is not redundant

-1 if row i is redundant

Example

 status = CPXbasicpresolve (env, lp, reducelb, reduceub, rowstat);

A pointer to the CPLEX environment, as returned by CPXopenCPLEX.

A pointer to a CPLEX LP problem object, as returned by CPXcreateprob.

An array to receive the strengthened lower bounds. The array must be of length at least the number of columns in the LP problem object. May be NULL.

An array to receive the strengthened upper bounds. The array must be of length at least the number of columns in the LP problem object. May be NULL.

An array to receive the status of the row. The array must be of length at least the number of rows in the LP problem object. May be NULL.

The routine returns zero on success and nonzero if an error occurs.

CPXbasicpresolve

Parameters:

Returns:

env	A pointer to the CPLEX environment, as returned by `CPXopenCPLEX`.
lp	A pointer to a CPLEX LP problem object, as returned by `CPXcreateprob`.
redlb	An array to receive the strengthened lower bounds. The array must be of length at least the number of columns in the LP problem object. May be NULL.
redub	An array to receive the strengthened upper bounds. The array must be of length at least the number of columns in the LP problem object. May be NULL.
rstat	An array to receive the status of the row. The array must be of length at least the number of rows in the LP problem object. May be NULL.