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My proj is from https://pennylane.ai/qml/demos/tutorial_rotoselect.html

In verifying the application of this theory in more complex circuits, the following problems occurred.

How to fix this, I tried the suggestions in github still no solution ? How to fix this, I tried the suggestions in github still no solution,

https://github.com/PennyLaneAI/pennylane/issues/1459

enter image description here

> WireError                                 Traceback (most recent call
> last) File d:\miniconda3\lib\site-packages\pennylane\_device.py:369,
> in Device.map_wires(self, wires)
>     368 try:
> --> 369     mapped_wires = wires.map(self.wire_map)
>     370 except WireError as e:
> 
> File d:\miniconda3\lib\site-packages\pennylane\wires.py:273, in
> Wires.map(self, wire_map)
>     272     if w not in wire_map:
> --> 273         raise WireError(f"No mapping for wire label {w} specified in wire map {wire_map}.")
>     275 new_wires = [wire_map[w] for w in self]
> 
> WireError: No mapping for wire label 0 specified in wire map
> OrderedDict([(tensor(18, requires_grad=True), 0)]).
> 
> The above exception was the direct cause of the following exception:
> 
> WireError                                 Traceback (most recent call
> last) Input In [11], in <cell line: 137>()
>     136 costs_rotosolve = []
>     137 for i in range(n_steps):
> --> 139     costs_rotosolve.append(cost(params_rsol, wires))
>     140     params_rsol = rotosolve_cycle(cost, params_rsol)
>     142 params_gd = init_params.copy()
> 
> Input In [11], in cost(params, wires)
>      89 def cost(params, wires):
> ---> 90     Z = circuit(params, wires)
>      91     return Z
> 
> File d:\miniconda3\lib\site-packages\pennylane\qnode.py:576, in
> QNode.__call__(self, *args, **kwargs)
>     569 using_custom_cache = (
>     570     hasattr(cache, "__getitem__")
>     571     and hasattr(cache, "__setitem__")
>     572     and hasattr(cache, "__delitem__")
>     573 )
>     574 self._tape_cached = using_custom_cache and self.tape.hash in cache
> --> 576 res = qml.execute(
>     577     [self.tape],
>     578     device=self.device,
>     579     gradient_fn=self.gradient_fn,
>     580     interface=self.interface,
>     581     gradient_kwargs=self.gradient_kwargs,
>     582     override_shots=override_shots,
>     583     **self.execute_kwargs,
>     584 )
>     586 if autograd.isinstance(res, (tuple, list)) and len(res) == 1:
>     587     # If a device batch transform was applied, we need to 'unpack'
>     588     # the returned tuple/list to a float.    (...)
>     595     # TODO: find a more explicit way of determining that a batch transform
>     596     # was applied.
>     598     res = res[0]
> 
> File
> d:\miniconda3\lib\site-packages\pennylane\interfaces\execution.py:409,
> in execute(tapes, device, gradient_fn, interface, mode,
> gradient_kwargs, cache, cachesize, max_diff, override_shots,
> expand_fn, max_expansion, device_batch_transform)
>     402     interface_name = [k for k, v in INTERFACE_NAMES.items() if interface in v][0]
>     404     raise qml.QuantumFunctionError(
>     405         f"{interface_name} not found. Please install the latest "
>     406         f"version of {interface_name} to enable the '{interface}' interface."
>     407     ) from e
> --> 409 res = _execute(
>     410     tapes, device, execute_fn, gradient_fn, gradient_kwargs, _n=1, max_diff=max_diff, mode=_mode
>     411 )
>     413 return batch_fn(res)
> 
> File
> d:\miniconda3\lib\site-packages\pennylane\interfaces\autograd.py:64,
> in execute(tapes, device, execute_fn, gradient_fn, gradient_kwargs,
> _n, max_diff, mode)
>      58     tape.trainable_params = qml.math.get_trainable_indices(params)
>      60 parameters = autograd.builtins.tuple(
>      61     [autograd.builtins.list(t.get_parameters()) for t in tapes]
>      62 )
> ---> 64 return _execute(
>      65     parameters,
>      66     tapes=tapes,
>      67     device=device,
>      68     execute_fn=execute_fn,
>      69     gradient_fn=gradient_fn,
>      70     gradient_kwargs=gradient_kwargs,
>      71     _n=_n,
>      72     max_diff=max_diff,
>      73 )[0]
> 
> File d:\miniconda3\lib\site-packages\autograd\tracer.py:48, in
> primitive.<locals>.f_wrapped(*args, **kwargs)
>      46     return new_box(ans, trace, node)
>      47 else:
> ---> 48     return f_raw(*args, **kwargs)
> 
> File
> d:\miniconda3\lib\site-packages\pennylane\interfaces\autograd.py:108,
> in _execute(parameters, tapes, device, execute_fn, gradient_fn,
> gradient_kwargs, _n, max_diff)
>      87 """Autodifferentiable wrapper around ``Device.batch_execute``.
>      88 
>      89 The signature of this function is designed to work around Autograd restrictions.    (...)
>     105 understand the consequences!
>     106 """
>     107 with qml.tape.Unwrap(*tapes):
> --> 108     res, jacs = execute_fn(tapes, **gradient_kwargs)
>     110 for i, r in enumerate(res):
>     112     if isinstance(res[i], np.ndarray):
>     113         # For backwards compatibility, we flatten ragged tape outputs
>     114         # when there is no sampling
> 
> File
> d:\miniconda3\lib\site-packages\pennylane\interfaces\execution.py:165,
> in cache_execute.<locals>.wrapper(tapes, **kwargs)
>     161         return (res, []) if return_tuple else res
>     163 else:
>     164     # execute all unique tapes that do not exist in the cache
> --> 165     res = fn(execution_tapes.values(), **kwargs)
>     167 final_res = []
>     169 for i, tape in enumerate(tapes):
> 
> File
> d:\miniconda3\lib\site-packages\pennylane\interfaces\execution.py:90,
> in cache_execute.<locals>.fn(tapes, **kwargs)
>      88 def fn(tapes, **kwargs):  # pylint: disable=function-redefined
>      89     tapes = [expand_fn(tape) for tape in tapes]
> ---> 90     return original_fn(tapes, **kwargs)
> 
> File d:\miniconda3\lib\contextlib.py:79, in
> ContextDecorator.__call__.<locals>.inner(*args, **kwds)
>      76 @wraps(func)
>      77 def inner(*args, **kwds):
>      78     with self._recreate_cm():
> ---> 79         return func(*args, **kwds)
> 
> File
> d:\miniconda3\lib\site-packages\pennylane_qiskit\qiskit_device.py:428,
> in QiskitDevice.batch_execute(self, circuits)
>     425 def batch_execute(self, circuits):
>     426     # pylint: disable=missing-function-docstring
> --> 428     compiled_circuits = self.compile_circuits(circuits)
>     430     # Send the batch of circuit objects using backend.run
>     431     self._current_job = self.backend.run(compiled_circuits, shots=self.shots, **self.run_args)
> 
> File
> d:\miniconda3\lib\site-packages\pennylane_qiskit\qiskit_device.py:417,
> in QiskitDevice.compile_circuits(self, circuits)
>     413 for circuit in circuits:
>     414     # We need to reset the device here, else it will
>     415     # not start the next computation in the zero state
>     416     self.reset()
> --> 417     self.create_circuit_object(circuit.operations, rotations=circuit.diagonalizing_gates)
>     419     compiled_circ = self.compile()
>     420     compiled_circ.name = f"circ{len(compiled_circuits)}"
> 
> File
> d:\miniconda3\lib\site-packages\pennylane_qiskit\qiskit_device.py:230,
> in QiskitDevice.create_circuit_object(self, operations, **kwargs)
>     218 """Builds the circuit objects based on the operations and measurements
>     219 specified to apply.
>     220     (...)
>     226         pre-measurement into the eigenbasis of the observables.
>     227 """
>     228 rotations = kwargs.get("rotations", [])
> --> 230 applied_operations = self.apply_operations(operations)
>     232 # Rotating the state for measurement in the computational basis
>     233 rotation_circuits = self.apply_operations(rotations)
> 
> File
> d:\miniconda3\lib\site-packages\pennylane_qiskit\qiskit_device.py:269,
> in QiskitDevice.apply_operations(self, operations)
>     265 circuits = []
>     267 for operation in operations:
>     268     # Apply the circuit operations
> --> 269     device_wires = self.map_wires(operation.wires)
>     270     par = operation.parameters
>     272     for idx, p in enumerate(par):
> 
> File d:\miniconda3\lib\site-packages\pennylane\_device.py:371, in
> Device.map_wires(self, wires)
>     369     mapped_wires = wires.map(self.wire_map)
>     370 except WireError as e:
> --> 371     raise WireError(
>     372         f"Did not find some of the wires {wires} on device with wires {self.wires}."
>     373     ) from e
>     375 return mapped_wires
> 
> WireError: Did not find some of the wires <Wires = [0]> on device with
> wires <Wires = [tensor(18, requires_grad=True)]>.
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8
  • $\begingroup$ I recommend you can consider follow Owen Lockwood youtube channel, and walk through the pennylane codebook. or challenge yourself first. $\endgroup$
    – poig
    Commented Jun 30, 2022 at 3:05
  • $\begingroup$ can you show your code $\endgroup$
    – poig
    Commented Jun 30, 2022 at 3:16
  • $\begingroup$ Sorry, the code is temporarily unavailable $\endgroup$ Commented Jun 30, 2022 at 3:24
  • 1
    $\begingroup$ I think the error is because your wires = tensor(18, requires_grad=True), it should be something like wires=5 $\endgroup$
    – poig
    Commented Jun 30, 2022 at 3:26
  • $\begingroup$ I think my mistake may be inspired by github.com/PennyLaneAI/pennylane/issues/1459 $\endgroup$ Commented Jun 30, 2022 at 3:27

1 Answer 1

1
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the main reason is because n_wires = np.tensor(18, requires_grad=True)

n_wires = np.tensor(18, requires_grad=True)
dev = qml.device("qiskit.aer", shots=1000, wires=n_wires)
@qml.qnode(dev)
def test(wires):
    qml.Hadamard(wires=wires[0])
    return [qml.expval(qml.PauliZ(i)) for i in range(n_wires)]

wires=range(n_wires)
test(wires)
$\endgroup$

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