Working on amplitude estimation simulation

src/qasp/problems/estimation.py

@@ -5,7 +5,8 @@
 import math
 from qiskit import ClassicalRegister, QuantumCircuit, QuantumRegister
 from qiskit.circuit.library import GroverOperator, QFT
-from ..oracle import QuantumOracle
+from ..oracle import Oracle, QuantumOracle
+from ..simul import __exec_circuit
 
 
 # +--------------------+
@@ -103,3 +104,69 @@ def circuit(
  circ.measure(list(range(t-m, t)), result) # Only m bits
 
  return circ
+
+
+# +-----------------------+
+# | Algoroithm simulation |
+# +-----------------------+
+
+def __measure_to_count(measurements: str, num_search_qubits: int) -> tuple[float, int]:
+ '''Convert the result of a measurement to to actual phase factor and the resulting solutions \
+ count.
+
+ #### Arguments
+ measurements (str): Measured bits.
+ num_search_qubits (int): Number of search qubits.
+
+ #### Return
+ tuple[float, int]: Phase factor and solutions count.
+ '''
+ phi = 0.0
+ for (idx, bit) in zip(range(len(measurements)), measurements):
+ phi += int(bit) * 2**(-idx-1)
+ print(measurements, phi)
+ phase = 2 * math.pi * phi
+ count = 2**num_search_qubits * (math.sin(phase / 2))**2
+
+ return (phase, count)
+
+
+def exec_count(
+ algorithm: QuantumCircuit,
+ oracle: Oracle,
+ m: int,
+ eps: float,
+ aux_qubits: list[int] = None
+) -> tuple[QuantumCircuit, float, int]:
+ '''Simulate the amplitude estimation circuit to approximate the number of solutions of the \
+ problem.
+
+ #### Arguments
+ algorithm (QuantumCircuit): Ciruit that implements the initialization algorithm.
+ oracle (Oracle): Pair of classical and quantum oracles.
+ m (int): Desired number of binary digits to be estimated.
+ eps (float): Complement of the desired success probability.
+ aux_qubits (list[int]): List of indices of auxiliary qubits (e.g. used by the oracle) \
+ that should not be used for the search procedure. Defaults to the empty list.
+
+ #### Return
+ tuple[QuantumCircuit, float, int]: Used circuit, measured phase, and estimated number \
+ of solutions.
+ '''
+ aux_qubits = [] if aux_qubits is None else aux_qubits
+ (_, q_oracle) = oracle # Classical oracle is unused
+
+ n = len(q_oracle.qubits) - len(aux_qubits) + 1 # Account for `aug`
+
+ # Build circuit
+ circ = circuit(algorithm, q_oracle, m, eps, aux_qubits)
+
+ # Run simulation
+ result = __exec_circuit(circ, shots=10000)
+ measurements = list(result.get_counts(circ).keys())[0]
+ print(result.get_counts())
+
+ # Compute results
+ (phase, count) = __measure_to_count(measurements, n)
+
+ return (circ, phase, count)