qiskit.aqua.algorithms.QSVM.get_kernel_matrix

static QSVM.get_kernel_matrix(quantum_instance, feature_map, x1_vec, x2_vec=None, enforce_psd=True)

Construct kernel matrix, if x2_vec is None, self-innerproduct is conducted.

Notes

When using statevector_simulator, we only build the circuits for Psi(x1)|0> rather than Psi(x2)^dagger Psi(x1)|0>, and then we perform the inner product classically. That is, for statevector_simulator, the total number of circuits will be O(N) rather than O(N^2) for qasm_simulator.

Parameters

• quantum_instance (QuantumInstance) – quantum backend with all settings

• feature_map (FeatureMap) – a feature map that maps data to feature space

• x1_vec (numpy.ndarray) – data points, 2-D array, N1xD, where N1 is the number of data, D is the feature dimension

• x2_vec (numpy.ndarray) – data points, 2-D array, N2xD, where N2 is the number of data, D is the feature dimension

• enforce_psd (bool) – enforces that the kernel matrix is positive semi-definite by setting negative eigenvalues to zero. This is only applied in the symmetric case, i.e., if x2_vec == None.

Returns

2-D matrix, N1xN2

Return type

numpy.ndarray