Planner Explanation

Ask MENOS how it planned a job and read the answer.

"""Ask MENOS how it planned a job, using the native API's explain()."""

from menos import Circuit, Opcode, RunOptions, run

# A 3-qubit GHZ circuit that measures every qubit.
circuit = Circuit(3, 3)
circuit.append(Opcode.H, [0])
circuit.append(Opcode.CX, [0, 1])
circuit.append(Opcode.CX, [1, 2])
for qubit in range(3):
    circuit.append_measure(qubit, qubit)

options = RunOptions()
options.shots = 100
options.seed = 5

result = run(circuit, options)
print(result.explain())

report = result.explain()
assert report.startswith("MENOS EXECUTION REPORT")
assert "candidate 0" in report  # every enumerated candidate is listed, winners and losers
assert sum(result.counts.values()) == 100
assert result.exact

Output

MENOS EXECUTION REPORT
circuit    qubits=3 clbits=3 operations=6 depth=4 global_phase=0
light_cone qubits 3->3 operations 6->6
candidate 0strategy=direct_dense feasible=true winner=false peak_bytes=128 work_units=96
candidate 1strategy=direct_stabilizer feasible=true winner=true peak_bytes=56 work_units=33
candidate 2strategy=direct_mps feasible=true winner=false peak_bytes=256 work_units=51
strategy   direct_stabilizer (exact)
region 0   qubits=[0,1,2] engine=stabilizer backend=cpu
estimated  state_bytes=56 work_units=33
actual     state_bytes=56 execute_s=0.000008 sample_s=0.000000

Three candidates were feasible. The stabilizer engine won with 33 work units against 51 for MPS and 96 for dense. The actual line reports what was measured; its timing will differ on your machine.

Reading it

Read Plan Explanation for every line.