dwave-examples/anneal-schedule-notebook

Demonstrates configuring the annealing schedule on D-Wave quantum computers.

anneal-schedule-notebook's Issues

Cell 18 fails as its problem exceeds the max runtime and gets rejected

Now that problems exceeding 1s in duration get rejected, cell 18 of this notebook fails to run completely as it tries to submit a problem with a long pause in the anneal schedule.

Cell 18:

anneal_time=[10.0, 100.0, 500.0]
pause_duration=[10.0, 100.0, 500.0]

# Create list of start times
num_points=5
s_low=0.2
s_high=0.6
pause_start=np.linspace(s_low, s_high, num=num_points)

success_prob = pd.DataFrame(index=range(len(anneal_time)*len(pause_duration)*len(pause_start)),
                                columns=["anneal_time", "pause_duration", "s_feature", "success_frac"],
                                data=None)
counter=0

print("Starting QPU calls...")
QPU_time=0.0
for anneal in anneal_time:
    for pause in pause_duration:
        for start in pause_start:
            schedule=[[0.0,0.0],[start*anneal,start],[start*anneal+pause, start],[anneal+pause, 1.0]]
            runs=950
            results = sampler_embedded.sample_ising(h, J,
                anneal_schedule=schedule,
                num_reads=runs, 
                answer_mode='raw',
                label='Notebook - Anneal Schedule',
                num_spin_reversal_transforms=1)
            success_prob.iloc[counter]={"anneal_time":anneal, 
                                        "pause_duration":pause, 
                                        "s_feature":start,
                                        "success_frac":np.count_nonzero(results.record.energy == -20.0)/runs}
            counter+=1
            QPU_time+=results.info['timing']['qpu_access_time']
        print("QPU calls remaining: ", len(anneal_time)*len(pause_duration)*len(pause_start)-counter)
            
print("QPU calls complete using", QPU_time/1000000.0, "seconds of QPU time.")

It returns the following error when fewer than 5 QPU calls are remaining:
SolverFailureError: The problem cannot be submitted because the estimated QPU access time of 1076943 microseconds for one or more of the problem's spin-reversal transforms exceeds the maximum of 1000000 microseconds for <solver name>. To resolve this issue, see the topic at https://docs.dwavesys.com/docs/latest/c_qpu_timing.html#keeping-within-the-runtime-limit.

Possible solutions: Reduce the pause, the number of reads, or increase the number of spin-reversal transforms.