Consider deprecating the VirtualGraphComposite

Open arcondello opened this issue 5 years ago • 1 comments

Reasons:

It is not (as far as I know) widely used
It requires significant QPU time to configure - we even have a warning to that effect
It is less relevant now with the lower noise processors and does not implement the latest protocols
Removing it would allow us to remove the dependency on dwave-drivers, and remove a lot of caching boilerplate

Dec 23 '20 21:12 arcondello

My 2c for this debate: I think that :func:~dwave.embedding.chain_strength.uniform_torque_compensation adds urgency, and that we need to either deprecate or update VG's chain_strength algo because my guess (based on just a small sample) is that despite improvements from adjusting flux biases, results from the max negative chain strength do not compare favorably with the calculated chain-strength from uniform_torque_compensation .

A 50-node clique BQM with biases generated by dimod.generators.randint(50, 'SPIN', low=0, high=5) and scaled down to the J range, reusing the embedding with VG produced unsatisfying results:

Chimera Non-VG: VG:
Pegasus Non-VG: VG:

Mar 18 '21 17:03 JoelPasvolsky