The latest pennylane-cirq requires simulate method without analytic argument.

[jaeyoo]

On 0.14.0, there was analytic argument in qml.device, so we could set if False and then add Cirq-based simulators. However, the latest version has no analytic, and it always requires simulate method.

In details, when we run the colab here, if we change the pennylane & pennylane-cirq versions to the latest, then it says:

AttributeError: 'CirqSimulator' object has no attribute 'simulate'.

[josh146]

Hi @jaeyoo! The latest version of PennyLane replaces the anlaytic keyword argument with shots=None. If you change to shots=None in the colab notebook, does it then work?

[jaeyoo]

Thank you @josh146 , I realized that the issue was caused by shots=None. After assigning some value to shots the error message's gone.

For the case of shots=None (or previously analytic=True), is simulate() mandatory? I mean, For the latest Cirq simulator, we can see:

cirq.sim.SimulatesExpectationValues.simulate_expectation_values()
cirq.sim.SimulatesFinalState.simulate()

and it seems to accept SimulatesFiniteState simulator only. Is it mandatory? What about SimulatesExpectationValues simulator..?

[josh146]

Glad it worked!

For the case of shots=None (or previously analytic=True), is simulate() mandatory?

I don't believe so, no; I think this is an artifact of the core of this plugin being written against an older Cirq version. If there are better ways of accessing expectation values, we should mark the plugin for an update to access these more efficient methods.

[jaeyoo]

Thank you Josh, yes, I hope the latest PennyLane-Cirq supports the latest Cirq too. Could you please add this feature into it?

[josh146]

@jaeyoo I've created a new issue here (#70), so will close this one for now 🙂 Feel free to comment on the other one in case I have missed any details!

I hope the latest PennyLane-Cirq supports the latest Cirq too

Just double checking, is anything broken using PennyLane with the latest Cirq version? Or is it more that there are newer features available?