[BUG] Documentation examples on pennylane.fourier.qnode_spectrum no longer work

[justinpickering]

Expected behavior

I expect to be able to run all the examples in the pennylane.fourier.qnode_spectrum https://docs.pennylane.ai/en/stable/code/api/pennylane.fourier.qnode_spectrum.html examples.

Actual behavior

Examples in the documentation should be fully executable, and not provide any errors.

Additional information

No response

Source code

n_qubits = 3
dev = qml.device("default.qubit", wires=n_qubits)

@qml.qnode(dev)
def circuit(x, y, z, w):
    for i in range(n_qubits):
        qml.RX(0.5*x[i], wires=i)
        qml.Rot(w[0,i,0], w[0,i,1], w[0,i,2], wires=i)
        qml.RY(2.3*y[i], wires=i)
        qml.Rot(w[1,i,0], w[1,i,1], w[1,i,2], wires=i)
        qml.RX(z, wires=i)
    return qml.expval(qml.Z(0))

x = np.array([1., 2., 3.])
y = np.array([0.1, 0.3, 0.5])
z = -1.8
w = np.random.random((2, n_qubits, 3))
print(qml.draw(circuit)(x, y, z, w))

res = qml.fourier.qnode_spectrum(circuit, argnum=[0, 1, 2])(x, y, z, w)
for inp, freqs in res.items():
    print(f"{inp}: {freqs}")

Tracebacks

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-4-a66971ae3a6a> in <cell line: 24>()
     22 print(qml.draw(circuit)(x, y, z, w))
     23 
---> 24 res = qml.fourier.qnode_spectrum(circuit, argnum=[0, 1, 2])(x, y, z, w)
     25 for inp, freqs in res.items():
     26     print(f"{inp}: {freqs}")

6 frames
/usr/local/lib/python3.10/dist-packages/numpy/core/numeric.py in within_tol(x, y, atol, rtol)
   2330     def within_tol(x, y, atol, rtol):
   2331         with errstate(invalid='ignore'), _no_nep50_warning():
-> 2332             return less_equal(abs(x-y), atol + rtol * abs(y))
   2333 
   2334     x = asanyarray(a)

ValueError: operands could not be broadcast together with shapes (27,3) (3,3)

System information

Name: PennyLane
Version: 0.39.0
Summary: PennyLane is a cross-platform Python library for quantum computing, quantum machine learning, and quantum chemistry. Train a quantum computer the same way as a neural network.
Home-page: https://github.com/PennyLaneAI/pennylane
Author: 
Author-email: 
License: Apache License 2.0
Location: /usr/local/lib/python3.10/dist-packages
Requires: appdirs, autograd, autoray, cachetools, networkx, numpy, packaging, pennylane-lightning, requests, rustworkx, scipy, toml, typing-extensions
Required-by: PennyLane_Lightning

Platform info:           Linux-6.1.85+-x86_64-with-glibc2.35
Python version:          3.10.12
Numpy version:           1.26.4
Scipy version:           1.13.1
Installed devices:
- lightning.qubit (PennyLane_Lightning-0.39.0)
- default.clifford (PennyLane-0.39.0)
- default.gaussian (PennyLane-0.39.0)
- default.mixed (PennyLane-0.39.0)
- default.qubit (PennyLane-0.39.0)
- default.qutrit (PennyLane-0.39.0)
- default.qutrit.mixed (PennyLane-0.39.0)
- default.tensor (PennyLane-0.39.0)
- null.qubit (PennyLane-0.39.0)
- reference.qubit (PennyLane-0.39.0)

Existing GitHub issues

• I have searched existing GitHub issues to make sure the issue does not already exist.