# Wire Error on IBM simulator **URL:** \ **Category:** PennyLane Plugins\ **Created:** [August 12, 2021, 3:41pm UTC](https://discuss.pennylane.ai/t/wire-error-on-ibm-simulator/1282 "2021-08-12T15:41:10Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![JosephT](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/josepht/32/1773_2.png) [@JosephT](https://discuss.pennylane.ai/u/JosephT)\ **Post date:** [August 12, 2021, 3:41pm UTC](https://discuss.pennylane.ai/t/wire-error-on-ibm-simulator/1282/1 "2021-08-12T15:41:10Z")
Hi there, I’m attempting to run the following circuit as part of a VQA, I can draw the circuit, and it gives me what I’m looking for, but I keep getting a Wire error when I attempt to run it. For context, this should implement Circuit 19 of [https://arxiv.org/pdf/1905.10876.pdf](https://arxiv.org/pdf/1905.10876.pdf) on p8. code: dev = qml.device(“qiskit.ibmq”,wires=11, backend=‘ibmq\_qasm\_simulator’) @qml.qnode(dev) def circuit19(params,n,x): # Requires 3n parameters ``` qml.templates.AngleEmbedding(x,wires=[i for i in range(n)]) index = 0 ``` # RX, RZ block ``` for i in range(n): qml.RX(params[index],wires=i) index += 1 qml.RZ(params[index],wires=i) index += 1 ``` # CRX ring ``` qml.CRX(params[index], wires=[n-1,0]) index += 1 for i in range(n-1): qml.CRX(params[index],wires=[n-2-i,n-1-i]) index +=1 return [qml.expval(qml.PauliZ(i)) for i in range(n)] ``` I try to input params = array([-0.0032389 , -0.01684838, 0.01511622, -0.00838866, 0.00166207, -0.00150847, -0.0006588 , 0.01190467, 0.00847062, -0.00101217, 0.00827397, 0.0164149 , -0.0077316 , 0.00027279, -0.00364212, -0.00350231, 0.00694448, -0.02124912, 0.02051644, 0.01000784, -0.00304314, 0.00105156, 0.01869766, 0.00629439, 0.00031815, 0.02199048, -0.0043911 , -0.01440873, 0.01359715, 0.01457333, 0.02708231, 0.00355718, -0.01900089]) n = 11 x = array([ 0.78199136, 0.78347364, 1.28256651, -1.09202159, 1.04188643, 0.27299406, -0.11969382, 1.16452877, 1.87329371, 0.56716628, 1. ]) I’m then given the following error message: File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\_device.py”, line 346, in map\_wires mapped\_wires = wires.map(self.wire\_map) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\wires.py”, line 271, in map raise WireError( WireError: No mapping for wire label 10 specified in wire map OrderedDict([(0, 0), (1, 1), (2, 2), (3, 3), (4, 4), (5, 5), (6, 6), (7, 7), (8, 8), (9, 9), (10, 10)]). The above exception was the direct cause of the following exception: Traceback (most recent call last): File “”, line 1, in circuit19(var,11,X\_train[0]) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\qnode.py”, line 598, in **call** res = self.qtape.execute(device=self.device) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\tape\tape.py”, line 1323, in execute return self.\_execute(params, device=device) File “C:\Users\josep\anaconda3\lib\site-packages\autograd\tracer.py”, line 48, in f\_wrapped return f\_raw(\*args, \*\*kwargs) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\interfaces\autograd.py”, line 165, in \_execute res = self.execute\_device(params, device=device) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\tape\tape.py”, line 1354, in execute\_device res = device.execute(self) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\_qubit\_device.py”, line 192, in execute self.apply(circuit.operations, rotations=circuit.diagonalizing\_gates, \*\*kwargs) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\_qiskit\qiskit\_device.py”, line 211, in apply applied\_operations = self.apply\_operations(operations) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\_qiskit\qiskit\_device.py”, line 247, in apply\_operations device\_wires = self.map\_wires(operation.wires) File “C:\Users\josep\anaconda3\lib\site-packages\pennylane\_device.py”, line 348, in map\_wires raise WireError( WireError: Did not find some of the wires \ on device with wires \. Any help would be greatly appreciated. ---
**Author:** ![christina](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/christina/32/583_2.png) [@christina](https://discuss.pennylane.ai/u/christina)\ **Post date:** [August 12, 2021, 5:17pm UTC](https://discuss.pennylane.ai/t/wire-error-on-ibm-simulator/1282/2 "2021-08-12T17:17:09Z")
Hi @JosephT🙂 You encountered a known quirk of PennyLane that we are trying to find a better workaround for. The package assumes all arguments are trainable by default, and so wraps any non-array input in an array. This causes a problem with labelling wires, because `11` and `np.array(11)` have different hash values, and thus are different wires. You can get the above code to work by calling ```auto circuit19(params, n=n, x=x) ``` since keyword arguments are not wrapped. ---
**Author:** ![JosephT](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/josepht/32/1773_2.png) [@JosephT](https://discuss.pennylane.ai/u/JosephT)\ **Post date:** [August 13, 2021, 9:06am UTC](https://discuss.pennylane.ai/t/wire-error-on-ibm-simulator/1282/3 "2021-08-13T09:06:46Z")
Hi @christina, Thanks for the explanation! That didn’t seem to work for me because the function call is then using undefined variables to give values. My workaround is just using: n = int(n) which redefines it within the function. ---
**Author:** ![christina](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/christina/32/583_2.png) [@christina](https://discuss.pennylane.ai/u/christina)\ **Post date:** [August 13, 2021, 9:12am UTC](https://discuss.pennylane.ai/t/wire-error-on-ibm-simulator/1282/4 "2021-08-13T09:12:00Z")
Glad it works for you now. We will keep your feedback in mind for future design and setting priorities on what to fix.