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CPXgetdblquality


Description

This function is used to access double-valued information about the quality of the current solution of an LP problem. A solution, though not necessarily a feasible or optimal one, must be available in the LP problem object. The quality values are returned in the double variables pointed to by the argument quality_p.

The maximum bound infeasibility identifies the largest bound violation, which helps determine the cause of an infeasible problem. If it exceeds the feasibility tolerance by only a small amount, it may be possible to obtain a feasible solution to the problem by increasing the feasibility tolerance. If a problem is optimal, it gives insight into the smallest setting for the feasibility tolerance that would not cause the problem to terminate infeasible.

Return Value

If the operation is successful, CPXgetdblquality() returns the value 0; if not, it returns a nonzero value to indicate an error.

Synopsis

 int CPXgetdblquality (CPXENVptr env,
                       CPXLPptr lp,
                       double *quality_p,
                       int what);

Arguments


CPXENVptr env
The pointer to the CPLEX environment as returned by CPXopenCPLEX().

CPXLPptr lp
A pointer to a CPLEX LP problem object as returned by CPXcreateprob().

double *quality_p
A pointer to a double variable in which the requested quality value is to be stored. If an error occurs, the value remains unchanged.

int what
A symbolic constant indicating the quality value to be retrieved. The possible quality values for a solution are listed in Appendix D, Solution Quality Values, Table D.1.

Example

status = CPXgetdblquality (env, lp, &max_x, CPX_MAX_X);

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