CPXgetquad

public int CPXgetquad(CPXCENVptr env, CPXCLPptr lp, int * nzcnt_p, int * qmatbeg, int * qmatind, double * qmatval, int qmatspace, int * surplus_p, int begin, int end)

Definition file: cplex.h

The routine CPXgetquad is used to access a range of columns of the matrix Q of a model with a quadratic objective function. The beginning and end of the range, along with the length of the arrays in which the nonzero entries of these columns are to be returned, must be specified.

Specifically, column j consists of the entries in qmatval and qmatind in the range from qmatbeg[j - begin] to qmatbeg[(j + 1) - begin]-1. (Column end consists of the entries from qmatbeg[end - begin] to nzcnt_p-1.) This array must be of length at least (end - begin + 1).

Note

If the value of qmatspace is zero, the negative of the value of surplus_p returned indicates the length needed for the arrays qmatind and qmatval.

Example

 status = CPXgetquad (env, lp, &nzcnt, qmatbeg, qmatind,
                      qmatval, qmatspace, &surplus, 0,
                      cur_numquad-1);

Parameters:

env	A pointer to the CPLEX environment as returned by `CPXopenCPLEX`.
lp	A pointer to a CPLEX problem object as returned by `CPXcreateprob`.
nzcnt_p	A pointer to an integer to contain the number of nonzeros returned; that is, the true length of the arrays `qmatind` and `qmatval`.
qmatbeg	An array to contain indices indicating where each of the requested columns of Q begins in the arrays `qmatval` and `qmatind`.
qmatind	An array to contain the row indices associated with the elements of `qmatval`. May be NULL if `qmatspace` is zero.
qmatval	An array to contain the nonzero coefficients of the specified columns. May be NULL if `qmatspace` is zero.
qmatspace	An integer indicating the length of the arrays `qmatind` and `qmatval`. May be zero.
surplus_p	A pointer to an integer to contain the difference between `qmatspace` and the number of entries in each of the arrays `qmatind` and `qmatval`. A nonnegative value of `surplus_p` indicates that the length of the arrays was sufficient. A negative value indicates that the length was insufficient and that the routine could not complete its task. In this case, `CPXgetquad` returns the value `CPXERR_NEGATIVE_SURPLUS`, and the negative value of `surplus_p` indicates the amount of insufficient space in the arrays.
begin	An integer indicating the beginning of the range of columns to be returned.
end	An integer indicating the end of the range of columns to be returned.

Returns:

The routine returns zero if successful and nonzero if an error occurs. The value CPXERR_NEGATIVE_SURPLUS indicates that insufficient space was available in the arrays qmatind and qmatval to hold the nonzero coefficients.