Qiskit: Get number of iterations for Iterative Amplitude Estimation

Question

Trying to count the number of uses of my circuit $A$ in Grover iterate circuit $Q= -AS_0A^{\dagger}S_x$.

However, Qiskit's amplitude estimation algorithms such as IAE or FAE accept only precision arguments like e.g. confidence of solution, error. I run them like this:

from qiskit.algorithms import IterativeAmplitudeEstimation, EstimationProblem, FasterAmplitudeEstimation

problem = EstimationProblem(state_operation=myqc, objective_qubits=[0])
algorithm = IterativeAmplitudeEstimation(**kwargs)
result = algorithm.estimate(problem)
amplitude = result.estimation

How can I get the number of total iterations along with the result or at least get the circuit? Do I need to create my own implementations of the algorithms?

Answer 1

For the number of iterations, you can do

for i,j in enumerate(result_delta._estimate_intervals):
    print(i,np.mean(j))

For the circuit result, you can try to do result.circuit_results, it might return a Statevector or counts dictionary.
and algorithm.construct_circuit(problem) to check the problem circuit.

#recommend way to view the problem gate
from qiskit import transpile
transpile(ae_delta.construct_circuit(problem),basis_gates = ['ry', 'cx','ccx','x']).draw()

For any more related coding questions, you can just do something like dir(result) to see its attribute, then check sources code or docs about these attributes for the explanation.

hope it is something you are looking for