CPXchgcoef() is used to change a single coefficient in the constraint matrix, objective coefficients, right-hand side or ranges of a CPLEX problem object. The coefficient is specified using its coordinates in the constraint matrix. When changing matrix coefficients from zero to nonzero values, be sure that the corresponding row and column indices exist in the problem, so that
The routine returns a zero on success, and a nonzero if an error occurs.
int CPXchgcoef (CPXCENVptr env, CPXLPptr lp, int i, int j, double newvalue);
The pointer to the CPLEX environment as returned by
A pointer to a CPLEX problem object as returned by
An integer that indicates the numerical index of the row in which the coefficient is located. The objective row is referenced with
i = -1.
An integer that indicates the numerical index of the column in which the coefficient is located. The RHS column is referenced with
j = -1. The range value column is referenced with
j = -2. If
j = -2 is specified and row
i is not a ranged row, an error status is returned.
The new value for the coefficient being changed.