# qiskit.optimization.applications.ising.vehicle_routing¶

Converts vehicle routing instances into a list of Paulis, and provides some related routines (extracting a solution, checking its objective function value).

Functions

 get_operator(instance, n, K) Converts an instance of a vehicle routing problem into a list of Paulis. get_vehiclerouting_cost(instance, n, K, x_sol) Computes the cost of a solution to an instance of a vehicle routing problem. get_vehiclerouting_matrices(instance, n, K) Constructs auxiliary matrices from a vehicle routing instance, get_vehiclerouting_solution(instance, n, K, …) Tries to obtain a feasible solution (in vector form) of an instance
get_operator(instance, n, K)[Quellcode]

Converts an instance of a vehicle routing problem into a list of Paulis.

Parameter
• instance (ndarray) – a customers-to-customers distance matrix.

• n (int) – the number of customers.

• K (int) – the number of vehicles available.

Rückgabetyp

WeightedPauliOperator

Rückgabe

operator for the Hamiltonian.

get_vehiclerouting_cost(instance, n, K, x_sol)[Quellcode]

Computes the cost of a solution to an instance of a vehicle routing problem.

Parameter
• instance (ndarray) – a customers-to-customers distance matrix.

• n (int) – the number of customers.

• K (int) – the number of vehicles available.

• x_sol (ndarray) – a solution, i.e., a path, in its binary representation.

Rückgabetyp

float

Rückgabe

objective function value.

get_vehiclerouting_matrices(instance, n, K)[Quellcode]
Constructs auxiliary matrices from a vehicle routing instance,

which represent the encoding into a binary quadratic program. This is used in the construction of the qubit ops and computation of the solution cost.

Parameter
• instance (ndarray) – a customers-to-customers distance matrix.

• n (int) – the number of customers.

• K (int) – the number of vehicles available.

Rückgabetyp

Tuple[ndarray, ndarray, float]

Rückgabe

a matrix defining the interactions between variables. a matrix defining the contribution from the individual variables. the constant offset.

get_vehiclerouting_solution(instance, n, K, result)[Quellcode]
Tries to obtain a feasible solution (in vector form) of an instance

of vehicle routing from the results dictionary.

Parameter
• instance (ndarray) – a customers-to-customers distance matrix.

• n (int) – the number of customers.

• K (int) – the number of vehicles available.

• result (MinimumEigensolverResult) – a result obtained by QAOA.run or VQE.run.

Rückgabetyp

List[int]

Rückgabe

a solution, i.e., a path, in its binary representation.

#TODO: support statevector simulation, results should be a statevector or counts format, not

a result from algorithm run