# Documentation

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 int GRBaddconstr ( GRBmodel *model, int numnz, int *cind, double *cval, char sense, double rhs, const char *constrname )

Add a new linear constraint to a model. Note that, due to our lazy update approach, the new constraint 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 constraint. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.

Arguments:

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

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

cind: Variable indices for non-zero values in the new constraint.

cval: Numerical values for non-zero values in the new constraint.

sense: Sense for the new constraint. Options are GRB_LESS_EQUAL, GRB_EQUAL, or GRB_GREATER_EQUAL.

rhs: Right-hand side value for the new constraint.

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

Example usage:

  int    ind[] = {1, 3, 4};
double val[] = {1.0, 2.0, 1.0};
/* x1 + 2 x3 + x4 = 1 */
error = GRBaddconstr(model, 3, ind, val, GRB_EQUAL, 1.0, "New");