SecondOrderExpansion

class SecondOrderExpansion(feature_dimension, depth=2, entangler_map=None, entanglement='full', data_map_func=<function self_product>)[source]

DEPRECATED. Second Order Expansion feature map.

This is a sub-class of PauliZExpansion where z_order is fixed at 2.

Parameters

  • feature_dimension (int) – The number of features

  • depth (int) – The number of repeated circuits. Defaults to 2, has a minimum value of 1.

  • entangler_map (Optional[List[List[int]]]) – Describes the connectivity of qubits, each list in the overall list describes [source, target]. Defaults to None where the map is created as per entanglement parameter. Note that the order in the list is the order of applying the two-qubit gate.

  • entanglement (str) – (‘full’ | ‘linear’), generate the qubit connectivity by a predefined topology. Defaults to full which connects every qubit to each other. Linear connects each qubit to the next.

  • data_map_func (Callable[[ndarray], float]) – A mapping function for data x which can be supplied to override the default mapping from self_product().

Attributes

SecondOrderExpansion.feature_dimension

returns feature dimension

SecondOrderExpansion.num_qubits

returns number of qubits

SecondOrderExpansion.support_parameterized_circuit

returns whether or not the sub-class support parameterized circuit

Methods

SecondOrderExpansion.construct_circuit(x[, …])

Construct the second order expansion based on given data.

SecondOrderExpansion.get_entangler_map(…)

get entangle map

SecondOrderExpansion.validate_entangler_map(…)

validate entangler map