_operator_map and _observable_map are now class attributes. #48
Conversation
…map are now required and are class attributes.
josh146
added
enhancement ✨
| Returns: | ||
| tuple(float, float): Mean photon number and variance. | ||
| """ | ||
| return state.mean_photon(wires), 0 |
There was a problem hiding this comment.
Do we want to return 0 for the variance here?
There was a problem hiding this comment.
No, I'm planning to submit a quick fix to SF today so that mean_photon also returns the variance
| # estimate the expectation value | ||
| # use central limit theorem, sample normal distribution once, only ok | ||
| # if shots is large (see https://en.wikipedia.org/wiki/Berry%E2%80%93Esseen_theorem) | ||
| ex = np.random.normal(ex, np.sqrt(var / self.shots)) |
There was a problem hiding this comment.
Should we modify this so that it actually runs the simulation self.shots times?
There was a problem hiding this comment.
I'm on the fence, what do you think? It would add significant overhead for large number of shots
There was a problem hiding this comment.
Might be worth making an issue about this
There was a problem hiding this comment.
I was thinking more that we need to be careful with a low number of shots; in that case, it is not a very good estimator. On the flip side, in that case, the overhead of repeatedly running the simulation wouldn't be too bad
There was a problem hiding this comment.
Could we use an heuristic to decide? I.e. for shots < 10 (arbitrarily chosen) we rerun the simulation, and for shots > 10, we use the central limit theorem
There was a problem hiding this comment.
yeah, probably the best solution for now. Maybe a number higher than 10 though?
|
Yes.
--
Christian Gogolin
http://www.cgogolin.de
|
Main changes:
_operator_mapand_observable_mapare now required class attributes for all devices. This simplifies plugin development, as the developer no longer needs to importDeviceErrorand raise issues if incorrect operators/observables are passed. Instead, this is handled in the background byDevice.Device.supported()now directly queries the operator and observable maps, and no longer needs to be overwritten by the developer either.Note that
_operator_mapand_observable_mapdo not need to map to anything useful (i.e. they could all map toNone, if the plugin developer wishes - it is entirely up to the developer). All that is required is that the supported keys are provided.Other changes:
default.qubitplugin to use the new suggested API