cirq_google.run_calibrations should work with SimulatedLocalEngines

[augustehirth]

Floquet calibration is a notebook that was designed to use the currently offline QCS to demonstrate how to calibrate a circuit to compensate for the errors that would arise by running it on a (QCS) device.

Without supplying QCS credentials, the notebook defaults to using a

Cirq/cirq-google/cirq_google/engine/simulated_local_engine.py

Line 31 in 8ea41a8

class SimulatedLocalEngine(AbstractLocalEngine):

per this line:

Cirq/cirq-google/cirq_google/engine/qcs_notebook.py

Line 123 in 8ea41a8

engine = create_noiseless_virtual_engine_from_latest_templates()

The notebook later fails because SimulatedLocalProcessor's run_calibration_async function is NotImplemented:

Cirq/cirq-google/cirq_google/engine/simulated_local_processor.py

Lines 276 to 277 in 8ea41a8

	async def run_calibration_async(self, *args, **kwargs):
	raise NotImplementedError

Note: For now, you need to set processor_id to weber to get past the first bug in this notebook.

For reference, EngineProcessor has an implementation:

Cirq/cirq-google/cirq_google/engine/engine_processor.py

Line 175 in fe67fcb

async def run_calibration_async(

that calls Engine's implementation:

Cirq/cirq-google/cirq_google/engine/engine.py

Line 409 in fe67fcb

async def run_calibration_async(

that calls EngineProgram's implementation:

Cirq/cirq-google/cirq_google/engine/engine_program.py

Line 213 in fe67fcb

async def run_calibration_async(

that actually creates the job.

---

It would be useful to be able to run calibrations on simulated engines, for the sake of:

1. Testing workflows with simulated engines before slotting in a hardware-backed engine.
2. Teaching how calibration works and demonstrating it's effects without access to hardware.
3. Experimenting with modified and new calibration procedures without access to hardware.

Specifically, let's implement cirq_google.simulated_local_processor.SimulatedLocalProcessor.run_calibration_async to have the same effective functionality as cirq_google.engine_processor.EngineProcessor.run_calibration_async. It should be able to handle the same input and produce the same output, with the caveat that any circuit executions are instead performed by the simulated processor.

I'm not sure what the scope of this request is, since SimulatedLocalProcessor and EngineProcessor seem to be relatively parallel constructs, and there seems to be a decent amount of complexity in handling protobuf'd requests.

Tentative priority: P2?

[augustehirth]

@dstrain115 @tanujkhattar

[dstrain115]

This is no longer relevant after #6442 removed this functionality.