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)

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

パラメータ

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

• n (int) – the number of customers.

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

戻り値の型

WeightedPauliOperator

戻り値

operator for the Hamiltonian.

get_vehiclerouting_cost(instance, n, K, x_sol)

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

パラメータ

• 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.

戻り値の型

float

戻り値

objective function value.

get_vehiclerouting_matrices(instance, n, K)

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.

パラメータ

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

• n (int) – the number of customers.

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

戻り値の型

Tuple[ndarray, ndarray, float]

戻り値

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)

Tries to obtain a feasible solution (in vector form) of an instance

of vehicle routing from the results dictionary.

パラメータ

• 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.

戻り値の型

ndarray

戻り値

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