GRBConstr#

class GRBConstr#

Gurobi constraint object. Constraints are always associated with a particular model. You create a constraint object by adding a constraint to a model (using GRBModel::addConstr), rather than by using a GRBConstr constructor.

The methods on constraint objects are used to get and set constraint attributes. For example, constraint right-hand sides can be queried by calling get ( GRB_DoubleAttr_RHS). Note that you can also query attributes for a set of constraints at once. This is done using the attribute query method on the GRBModel object (GRBModel::get).

The full list of attributes can be found in the Attributes section of this document. Examples of how to query and set attributes can also be found in this section.

char get(GRB_CharAttr attr)#

Query the value of a char-valued attribute.

Parameters:

attr – The attribute being queried.

Returns:

The current value of the requested attribute.

double get(GRB_DoubleAttr attr)#

Query the value of a double-valued attribute.

Parameters:

attr – The attribute being queried.

Returns:

The current value of the requested attribute.

int get(GRB_IntAttr attr)#

Query the value of an int-valued attribute.

Parameters:

attr – The attribute being queried.

Returns:

The current value of the requested attribute.

string get(GRB_StringAttr attr)#

Query the value of a string-valued attribute.

Parameters:

attr – The attribute being queried.

Returns:

The current value of the requested attribute.

int index()#

This method returns the current index, or order, of the constraint in the underlying constraint matrix.

Note that the index of a constraint may change after subsequent model modifications.

Returns:

-2: removed, -1: not in model, otherwise: index of the constraint in the model

bool sameAs(GRBConstr constr2)#

Check whether two constraint objects refer to the same constraint.

Parameters:

constr2 – The other constraint.

Returns:

Boolean result indicates whether the two constraint objects refer to the same model constraint.

void set(GRB_CharAttr attr, char newvalue)#

Set the value of a char-valued attribute.

Parameters:

  • attr – The attribute being modified.

  • newvalue – The desired new value of the attribute.

void set(GRB_DoubleAttr attr, double newvalue)#

Set the value of a double-valued attribute.

Parameters:

  • attr – The attribute being modified.

  • newvalue – The desired new value of the attribute.

void set(GRB_IntAttr attr, int newvalue)#

Set the value of an int-valued attribute.

Parameters:

  • attr – The attribute being modified.

  • newvalue – The desired new value of the attribute.

void set(GRB_StringAttr attr, const string &newvalue)#

Set the value of a string-valued attribute.

Parameters:

  • attr – The attribute being modified.

  • newvalue – The desired new value of the attribute.