Adding a qsearch example using QFactor-Sample

examples/qsearch_using_qfactor_sample.py

@@ -0,0 +1,84 @@
+from __future__ import annotations
+
+from timeit import default_timer as timer
+
+import numpy as np
+from bqskit import Circuit
+from bqskit.compiler import Compiler
+from bqskit.ir.gates import CNOTGate
+from bqskit.ir.gates import VariableUnitaryGate
+from bqskit.passes import QSearchSynthesisPass
+from bqskit.passes import SimpleLayerGenerator
+from bqskit.qis.unitary import UnitaryMatrix
+
+from qfactorjax.qfactor_sample_jax import QFactorSampleJax
+
+
+num_multistarts = 32
+
+
+qfactor_sample_gpu_instantiator = QFactorSampleJax(
+
+    dist_tol=1e-8,       # Stopping criteria for distance
+
+    max_iters=100000,      # Maximum number of iterations
+    min_iters=6,          # Minimum number of iterations
+
+    # Regularization parameter - [0.0 - 1.0]
+    # Increase to overcome local minima at the price of longer compute
+    beta=0.0,
+    amount_of_validation_states=2,
+
+    diff_tol_r=1e-4,
+    overtrain_relative_threshold=0.1,
+)
+
+
+instantiate_options = {
+    'method': qfactor_sample_gpu_instantiator,
+    'multistarts': num_multistarts,
+}
+
+toffoli = np.array([
+    [1, 0, 0, 0, 0, 0, 0, 0],
+    [0, 1, 0, 0, 0, 0, 0, 0],
+    [0, 0, 1, 0, 0, 0, 0, 0],
+    [0, 0, 0, 1, 0, 0, 0, 0],
+    [0, 0, 0, 0, 1, 0, 0, 0],
+    [0, 0, 0, 0, 0, 1, 0, 0],
+    [0, 0, 0, 0, 0, 0, 0, 1],
+    [0, 0, 0, 0, 0, 0, 1, 0],
+])
+toffoli = UnitaryMatrix(toffoli)
+in_circuit = Circuit.from_unitary(toffoli)
+
+
+search_layer_gen = SimpleLayerGenerator(
+    two_qudit_gate=CNOTGate(), single_qudit_gate_1=VariableUnitaryGate(1),
+)
+
+passes = [
+    QSearchSynthesisPass(
+        layer_generator=search_layer_gen,
+        instantiate_options=instantiate_options,
+    ),
+]
+
+with Compiler('localhost') as compiler:
+    start = timer()
+    out_circuit = compiler.compile(in_circuit, passes)
+    end = timer()
+    run_time = end - start
+
+
+dist = out_circuit.get_unitary().get_distance_from(in_circuit.get_unitary(), 1)
+
+print(
+    f'QSearch took {run_time} '
+    f'seconds using QFactor-Sample JAX instantiation method.',
+)
+
+print(
+    f'Circuit finished with gates: {out_circuit.gate_counts}, '
+    f'and the distance is {dist}',
+)