jgermain48
commented
3 years ago looking at the code further the issue doesn't happen if I comment out this line...reason this method isn't compatible with the simulator (again thought this version of the circuit worked yesterday)
Information
What is the current behavior?
Simulation fails to produce results. Simulation worked on my circuit yesterday...but today it fails. I don't think I've made any changes. Will run on real hardware fine.
Errors produced:
/Users/juliegermain/opt/anaconda3/envs/QuantumResearch/bin/python "/Users/juliegermain/Library/Application Support/JetBrains/PyCharmCE2020.3/scratches/QuantumResearch/scratch_5.py" [] Simulation failed and returned the following error message: ERROR: Failed to load qobj: Unable to cast Python instance to C++ type (compile in debug mode for details) Traceback (most recent call last): File "/Users/juliegermain/Library/Application Support/JetBrains/PyCharmCE2020.3/scratches/QuantumResearch/scratch_5.py", line 45, in
hist = plot_histogram(result.get_counts())
File "/Users/juliegermain/opt/anaconda3/envs/QuantumResearch/lib/python3.8/site-packages/qiskit/visualization/counts_visualization.py", line 219, in plot_histogram
all_vals = np.concatenate(all_pvalues).ravel()
File "<__array_function__ internals>", line 5, in concatenate
ValueError: need at least one array to concatenate
Process finished with exit code 1
Steps to reproduce the problem
Here is a scaled back version of the circuit that shows the issue:
from qiskit.tools.visualization import plot_histogram from qiskit import * from qiskit.extensions import Initialize import matplotlib.pyplot as plt
def draw_circuit(qc): qc.draw(output='mpl') plt.show()
sim_on = 1
qd0 = QuantumRegister(1,'qd0') qa0 = QuantumRegister(1,'qa0') qa1 = QuantumRegister(1,'qa1') qd1 = QuantumRegister(1,'qd1') qd2 = QuantumRegister(1,'qd2') crr = ClassicalRegister(1) shor_qc = QuantumCircuit(qd0,qd1,qd2,qa0,qa1,crr)
initial_value = 1
end-to-end circuit initialization method
if initial_value == 1: initial_data = '1' elif initial_value == 0: initial_data = '0'
init_gate = Initialize(initial_data) init_gate.label = "init" inverse_init_gate = init_gate.gates_to_uncompute() shor_qc.append(init_gate,qd0)
shor_qc.barrier()
shor_qc.measure(qd0,crr)
draw_circuit(shor_qc)
if sim_on == 1:
simulator = Aer.get_backend('aer_simulator')
What is the expected behavior?
produce a histogram with results. Note: I can run on real hardware and it works fine. Circuit is created and drawn. I had been running yesterday on qasm_simulator. I tried running on aer_simulator as a test...and issue still present.
Suggested solutions
No idea.