CPXXqpindefcertificate and CPXqpindefcertificate

The routine CPXXqpindefcertificate/CPXqpindefcertificate computes a vector x that satisfies the inequality x'Qx < 0.

int CPXXqpindefcertificate( CPXCENVptr env, CPXCLPptr lp, double * x )

int CPXqpindefcertificate( CPXCENVptr env, CPXCLPptr lp, double * x )

Description

The routine CPXXqpindefcertificate/CPXqpindefcertificate computes a vector x that satisfies the inequality x'Qx < 0. Such a vector demonstrates that the matrix Q violates the assumption of positive semi-definiteness, and can be an aid in debugging a user's program if indefiniteness is an unexpected outcome.

Arguments

env: A pointer to the CPLEX environment as returned by CPXXopenCPLEX/CPXopenCPLEX.
lp: A pointer to a CPLEX problem object as returned by CPXXcreateprob/CPXcreateprob.
x: An array to receive the values of the vector that is to be returned. The length of this array must be the same as the number of columns in the problem, which can be obtained by calling CPXXgetnumcols/CPXgetnumcols for example.

Return

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

Example


 status = CPXqpindefcertificate (env, lp, x);