execute with PEC

[YuNariai]

I used the ibm executor from ZNE example:

def ibmq_executor(circuit: qiskit.QuantumCircuit, shots: int = 8192) -> float:
    
        job = qiskit.execute(
            experiments=circuit,
            backend=backend,
            optimization_level=0,  # Important to preserve folded gates.
            shots=shots
        )
    
    # Convert from raw measurement counts to the expectation value
    counts = job.result().get_counts()
    if counts.get("0") is None:
        expectation_value = 0.
    else:
        expectation_value = counts.get("0") / shots
    return expectation_value

The circuit I run is

circ = QuantumCircuit(3, 3)
circ.h(0)
circ.cx(0, 1)
circ.cx(1, 2)
circ.measure([0, 1, 2], [0, 1, 2])

This executor and circuit work well with zne.execute_with_zne
Then I tried pec.execute_with_pec, the error is

[purva-thakre]

@YuNariai Which representation are you using for PEC?