CPXaddcols

The routine CPXaddcols adds columns to a specified CPLEX problem object. This routine may be called any time after a problem object is created via CPXcreateprob.

The routine CPXaddcols is very similar to the routine CPXaddrows. The primary difference is that CPXaddcols cannot add coefficients in rows that do not already exist (that is, in rows with index greater than the number returned by CPXgetnumrows); whereas CPXaddrows can add coefficients in columns with index greater than the value returned by CPXgetnumcols, by the use of the ccnt argument. (See the discussion of the ccnt argument for CPXaddrows.) Thus, CPXaddcols has no variable rcnt and no array rowname.

The routine CPXnewrows can be used to add empty rows before adding new columns via CPXaddcols.

The nonzero elements of every column must be stored in sequential locations in the array cmatval from position cmatbeg[i] to cmatbeg[i+1] (or from cmatbeg[i] to nzcnt-1 if i=ccnt-1). Each entry, cmatind[i], indicates the row number of the corresponding coefficient, cmatval[i]. Unlike CPXcopylp, all columns must be contiguous, and cmatbeg[0] must be 0.

When you build or modify your model with this routine, you can verify that the results are as you intended by calling CPXcheckaddcols during application development.

Example

 status = CPXaddcols (env, lp, ccnt, nzcnt, obj, cmatbeg,
                      cmatind, cmatval, lb, ub, newcolname);

A pointer to the CPLEX environment as returned by the CPXopenCPLEX routine.

A pointer to a CPLEX problem object as returned by CPXcreateprob.

An integer that indicates the number of new columns being added to the constraint matrix.

An integer that indicates the number of nonzero constraint coefficients to be added to the constraint matrix.

An array of length ccnt containing the objective function coefficients of the new variables. May be NULL, in which case, the objective coefficients of the new columns are set to 0.0.

Array that specifies the nonzero elements of the columns being added.

Array that specifies the nonzero elements of the columns being added. The format is similar to the format used to specify the constraint matrix in the routine CPXcopylp. (See description of matbeg, matcnt, matind, and matval in that routine).

An array of length ccnt containing the lower bound on each of the new variables. Any lower bound that is set to a value less than or equal to that of the constant -CPX_INFBOUND is treated as negative infinity. CPX_INFBOUND is defined in the header file cplex.h. May be NULL, in which case the lower bounds of the new columns are set to 0.0.

An array of length ccnt containing the upper bound on each of the new variables. Any upper bound that is set to a value greater than or equal to that of the constant CPX_INFBOUND is treated as infinity. CPX_INFBOUND is defined in the header file cplex.h. May be NULL, in which case the upper bounds of the new columns are set to CPX_INFBOUND (positive infinity).

An array of length ccnt containing pointers to character strings that specify the names of the new variables added to the problem object. May be NULL, in which case the new columns are assigned default names if the columns already resident in the CPLEX problem object have names; otherwise, no names are associated with the variables. If column names are passed to CPXaddcols but existing variables have no names assigned, default names are created for them.

The routine returns zero if successful and nonzero if an error occurs.

CPXaddcols

Parameters:

Returns:

env	A pointer to the CPLEX environment as returned by the `CPXopenCPLEX` routine.
lp	A pointer to a CPLEX problem object as returned by `CPXcreateprob`.
ccnt	An integer that indicates the number of new columns being added to the constraint matrix.
nzcnt	An integer that indicates the number of nonzero constraint coefficients to be added to the constraint matrix.
obj	An array of length `ccnt` containing the objective function coefficients of the new variables. May be NULL, in which case, the objective coefficients of the new columns are set to 0.0.
cmatbeg	Array that specifies the nonzero elements of the columns being added.
cmatind	Array that specifies the nonzero elements of the columns being added.
cmatval	Array that specifies the nonzero elements of the columns being added. The format is similar to the format used to specify the constraint matrix in the routine `CPXcopylp`. (See description of `matbeg`, `matcnt`, `matind`, and `matval` in that routine).
lb	An array of length `ccnt` containing the lower bound on each of the new variables. Any lower bound that is set to a value less than or equal to that of the constant `-CPX_INFBOUND` is treated as negative infinity. `CPX_INFBOUND` is defined in the header file `cplex.h`. May be NULL, in which case the lower bounds of the new columns are set to 0.0.
ub	An array of length `ccnt` containing the upper bound on each of the new variables. Any upper bound that is set to a value greater than or equal to that of the constant `CPX_INFBOUND` is treated as infinity. `CPX_INFBOUND` is defined in the header file `cplex.h`. May be NULL, in which case the upper bounds of the new columns are set to `CPX_INFBOUND` (positive infinity).
colname	An array of length `ccnt` containing pointers to character strings that specify the names of the new variables added to the problem object. May be NULL, in which case the new columns are assigned default names if the columns already resident in the CPLEX problem object have names; otherwise, no names are associated with the variables. If column names are passed to `CPXaddcols` but existing variables have no names assigned, default names are created for them.