CPXgetcols

int CPXPUBLIC CPXgetcols(CPXCENVptr env, CPXCLPptr lp, int * nzcnt_p, int * cmatbeg, int * cmatind, double * cmatval, int cmatspace, int * surplus_p, int begin, int end)

Definition file: cplex.h

Include files: cplex.h

The routine CPXgetcols is used to access a range of columns of the constraint matrix of a CPLEX problem object. 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.

Note

If the value of cmatspace is zero, the negative of the value of *surplus_p returned indicates the length needed for the arrays cmatind and cmatval.

Example

 status = CPXgetcols (env, lp, &nzcnt, cmatbeg, cmatind,
                      cmatval, cmatspace, &surplus, 0,
                      cur_numcols-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 `cmatind` and `cmatval`.
cmatbeg	An array to contain indices indicating where each of the requested columns begins in the arrays `cmatval` and `cmatind`. Specifically, column `j` consists of the entries in `cmatval` and `cmatind` in the range from `cmatbeg[j - begin]` to `cmatbeg[(j + 1) - begin]-1`. (Column `end` consists of the entries from `cmatbeg[end - begin]` to `nzcnt_p-1`.) This array must be of length at least (`end` - `begin+ 1`).
cmatind	An array to contain the row indices associated with the elements of `cmatval`. May be NULL if `cmatspace` is zero.
cmatval	An array to contain the nonzero coefficients of the specified columns. May be NULL if `cmatspace` is zero.
cmatspace	An integer indicating the length of the arrays `cmatind` and `cmatval`. May be zero.
surplus_p	A pointer to an integer to contain the difference between `cmatspace` and the number of entries in each of the arrays `cmatind` and `cmatval`. 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, `CPXgetcols` 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 on success and nonzero if an error occurs. The value CPXERR_NEGATIVE_SURPLUS indicates that insufficient space was available in the arrays cmatind and cmatval to hold the nonzero coefficients.