Hi

I get the following error

Runtime Error. ops operation Rot(<autograd.numpy.numpy_boxes.ArrayBox object at 0x0000029E30F68A80>, <autograd.numpy.numpy_boxes.ArrayBox object at 0x0000029E30F6AE80>, <autograd.numpy.numpy_boxes.ArrayBox object at 0x0000029E30F68500>, wires=[0]) must occur prior to measurements. Please place earlier in the queue.

```
coeffs = [1., 1., 1.]
obs = [qml.PauliX(0), qml.PauliZ(0),qml.PauliX(0)]
H = qml.Hamiltonian(coeffs, obs)
def circuit(params, wires=0):
qml.RX(params[0], wires=wires)
qml.RZ(params[0], wires=wires)
qml.RX(params[0], wires=wires)
# This is the cost function
@qml.qnode(dev)
def cost_function(params):
circuit(params)
return qml.expval(H)
```

Hi @Rajesh_Chaurasia ,

Unfortunately the code you shared doesn’t seem to be the full code you’re using (I can’t see what ‘params’ are for you).

Could you please provide the following information?

- The output of
`qml.about()`

- A minimal (but self-contained) working example

This is the simplest version of the code that reproduces the problem. It should include all necessary imports, data, functions, etc., so that we can copy-paste the code and reproduce the problem. However it shouldn’t contain any unnecessary data, functions, …, for example gates and functions that can be removed to simplify the code.
- The full error traceback.

If you’re not sure what these mean then make sure to check out this video

Hi Catalina

I am uploading the file here , hope its fine.

TEST-CHALLENGE.txt (5.4 KB)

Thanks for your reply.I am tying to correct issues as mentioned by you

Hi @Rajesh_Chaurasia ,

Is your question about a specific coding challenge or a specific codercise?

Also, could you please post these two key pieces of information?

- The output of
`qml.about()`

- The full error traceback

Thanks!