"Parameter" not defined in the current context? #9627
Description
Environment
- Qiskit Terra version:
{'qiskit-terra': '0.23.1', 'qiskit-aer': '0.11.2', 'qiskit-ignis': None, 'qiskit-ibmq-provider': '0.20.0', 'qiskit': '0.41.0', 'qiskit-nature': None, 'qiskit-finance': None, 'qiskit-optimization': None, 'qiskit-machine-learning': None} - Python version: Python 3.9.12
- Operating system: MacOS Ventura 13.1
Code
This doesn't work.
from qiskit import QuantumCircuit, ClassicalRegister, QuantumRegister
from qiskit.circuit.library.standard_gates import CUGate, RZGate
from qiskit.circuit import Parameter
p1 = Parameter("p1")
qr = QuantumRegister(4, name="qr")
cr = ClassicalRegister(4, name="cr")
qc = QuantumCircuit(qr, cr, name="qc")
qc.append(
CUGate(p1, 2.3864521352475245, 5.897054719225356, 0.5112149185250571),
qargs=[qr[0], qr[2]],
cargs=[],
)
qc = qc.bind_parameters(
{
p1: 0.5112149185250571,
}
)
from qiskit.qasm3 import dumps
print(dumps(qc))
# KeyError: "'p1' is not defined in the current context"whereas this works. Not sure if I understand the reason.
from qiskit import QuantumCircuit, ClassicalRegister, QuantumRegister
from qiskit.circuit.library.standard_gates import CUGate, RZGate
from qiskit.circuit import Parameter
p1 = Parameter("p1")
qr = QuantumRegister(4, name="qr")
cr = ClassicalRegister(4, name="cr")
qc = QuantumCircuit(qr, cr, name="qc")
qc.append(
RZGate(p1),
qargs=[qr[0]],
cargs=[],
)
qc = qc.bind_parameters(
{
p1: 0.5112149185250571,
}
)
from qiskit.qasm3 import dumps
print(dumps(qc))
# OPENQASM 3;
# include "stdgates.inc";
# bit[4] cr;
# qubit[4] _all_qubits;
# let qr = _all_qubits[0:3];
# rz(0.511214918525057) qr[0];