def _set_capacity_dimension_constraints(
self, data: VehicleRoutingProblemInstance, routing: RoutingModel,
manager: RoutingIndexManager):
if data.courier_capacities is None:
return
def demand_callback(index):
node = manager.IndexToNode(index)
return data.node_demands[node]
capacity_callback = routing.RegisterUnaryTransitCallback(
demand_callback)
routing.AddDimensionWithVehicleCapacity(
capacity_callback,
0, # waiting time
data.courier_capacities, # maximum distance per vehicle
False, # Force start cumul to zero.
self.CAPACITY_DIMENSION_NAME)
capacity_dimension = routing.GetDimensionOrDie(
self.CAPACITY_DIMENSION_NAME)
for courier_idx, start_utilization in enumerate(
data.start_utilizations):
node_idx = routing.Start(courier_idx)
self._set_constraint_on_var(
node_idx,
TimeWindowConstraint(node=node_idx,
is_hard=True,
from_time=start_utilization,
to_time=start_utilization),
capacity_dimension)
def add_capacity_constraints(routing: pywrapcp.RoutingModel, data: dict,
demand_callback):
"""
Add capacity constraints.
"""
routing.AddDimensionWithVehicleCapacity(
evaluator=demand_callback,
slack_max=0, # null slack
# vehicle maximum capacities
vehicle_capacities=data['vehicle_capacities'],
fix_start_cumul_to_zero=True, # start cumul to zero
name='Capacity',
)
def add_capacity_constraints(routing: pywrapcp.RoutingModel, data: dict,
demand_callback):
"""
Add capacity constraints.
"""
demand_callback_index = routing.RegisterUnaryTransitCallback(demand_callback)
routing.AddDimensionWithVehicleCapacity(
demand_callback_index,
slack_max=0, # null slack
# vehicle maximum capacities
vehicle_capacities=data['vehicle_capacities'],
fix_start_cumul_to_zero=True, # start cumul to zero
name='Capacity',
)
def apply(self, solver: RoutingModel):
"""Vehicle's occupation is restricted based on demand"""
callback_index = solver.RegisterUnaryTransitCallback(self._callback)
solver.AddDimensionWithVehicleCapacity(
evaluator_index=callback_index,
slack_max=0,
vehicle_capacities=[
vehicle.capacity
for vehicle in self.problem.vehicles.values()
],
fix_start_cumul_to_zero=True,
name='capacity_constraint'
)
def add_capacity_constraints(
routing: RoutingModel,
manager: RoutingIndexManager,
data: dict,
demand_callback_index: int,
) -> None:
"""
Add capacity constraints.
"""
routing.AddDimensionWithVehicleCapacity(
demand_callback_index,
slack_max=0, # null capacity slack
vehicle_capacities=data['vehicle_capacities'], # vehicle maximum capacities
fix_start_cumul_to_zero=True, # start cumul to zero
name='Capacity',
)
def apply(self, manager: pywrapcp.RoutingModel,
routing: pywrapcp.RoutingModel, data_model: DataModel):
def demand_callback(from_index):
"""Returns the demand of the node."""
# Convert from routing variable Index to demands NodeIndex.
from_node = manager.IndexToNode(from_index)
return data_model.demands[from_node]
demand_callback_index = routing.RegisterUnaryTransitCallback(
demand_callback)
routing.AddDimensionWithVehicleCapacity(
demand_callback_index,
0, # null capacity slack
data_model.vehicle_capacities,
True, # start cumul to zero
'Capacity')
return routing
def add_capacity_constraints(
routing: RoutingModel,
manager: RoutingIndexManager,
data: dict,
demand_callback_index: int,
) -> None:
"""
Since the capacity constraints involve
the weight of the load a vehicle is carrying
a quantity that accumulates over the route
we need to create a dimension for capacities
"""
routing.AddDimensionWithVehicleCapacity(
demand_callback_index,
slack_max=0, # null capacity slack
vehicle_capacities=data[
'vehicle_capacities'], # vehicle maximum capacities
fix_start_cumul_to_zero=True, # start cumul to zero
name='Capacity',
)