int GRBaddvar ( GRBmodel *model,
    int numnz,
    int *vind,
    double *vval,
    double obj,
    double lb,
    double ub,
    char vtype,
    const char *varname )

Add a new variable to a model. Note that, due to our lazy update approach, the new variable won't actually be added until you update the model (using GRBupdatemodel), optimize the model (using GRBoptimize), or write the model to disk (using GRBwrite).

Return value:

A non-zero return value indicates that a problem occurred while adding the variable. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.


model: The model to which the new variable should be added.

numnz: The number of non-zero coefficients in the new column.

vind: Constraint indices associated with non-zero values for the new variable.

vval: Numerical values associated with non-zero values for the new variable.

obj: Objective coefficient for the new variable.

lb: Lower bound for the new variable.

ub: Upper bound for the new variable.

vtype: Type for the new variable. Options are GRB_CONTINUOUS, GRB_BINARY, GRB_INTEGER, GRB_SEMICONT, or GRB_SEMIINT.

varname: Name for the new variable. This argument can be NULL, in which case the variable is given a default name.

Example usage:

  int    ind[] = {1, 3, 4};
  double val[] = {1.0, 1.0, 1.0};
  error = GRBaddvar(model, 3, ind, val, 1.0, 0.0, GRB_INFINITY,
                    GRB_CONTINUOUS, "New");