PegasusTools

Utilities and applications for D-Wave annealing problems. (Under highly diabatic development)

Requirements

• D-Wave Ocean SDK
• Numpy
• Scipy
• Pandas
• Pytables
• NetworkX
• Pyyaml

To install the editable (development) package, run pip install -e .

Examples

Anneal a simple ferromagnetic chain gadget embedded in a single Pegasus unit cell, automatically repeating the embedding throughout the hardware graph to gather a large number of samples.

pgt-cell-anneal -v --tf 20 --rand-gauge --reps 3 ./examples/fm_gadget.txt ./examples/fm_gadget_out

Output: fm_gadget_out_samps.csv

blabel,num_occurrences,energy
0,92514,-7.5
252,9697,-6.5
254,10900,-6.5
255,12172,-6.5
192,743,-6.0
224,729,-6.0
128,34,-5.5
.....

Generate a L=5 QAC topology from the default D-Wave sampler, and plot the logical topology.

pgt-qac-top
-L 5
--plot qac_L5_dwa4.1.pdf
--labels pqac_L5_labels.json
pqac_L5.txt

The main output is the adjacency list pqac_L5.txt. The additional output pqac_L5_labels.json maps the linear indices of the L=5 topology to their coordinates on the hardware graph. See the comments in qac.PegasusQACGraph for details.

Use the above QAC topology to generate a random spin glass instance, using a fixed random seed (which includes an instance index -n 0)

pgt-gen -n 0  --seed 1148089361  pqac_L5.txt s28 qac_s28_L5_0.txt

The s28 instance class are Sidon-28 instances with a maximum range of 28. The output file qac_s28_L5_0.txt is a (relatively) standard three-column text specification of the instance (i j Jij/i i hi).

To sample the QAC instance with the D-Wave sampler, run

pgt-qac --tf 3.0  -n 64 --reps 10 -R  --scale-j=28.0  --qac-penalty=0.2 --qac-mode=qac \
    --qac-mapping pqac_L5_labels.json  qac_s28_L5_0.txt qac_p0.2_L5_0_tf3.0

This command runs 10 repetitions (--reps) of the anneal, each with a random hardware-level gauge (-R) and 64 samples per repetition (-n), using a linear anneal schedule of 3 us (--tf).

Some advanced schedules constructions are supported. For a pause and ramp schedule, specify pr <t1> <sp> <tp> <tr>, where t1 is the initial anneal time, sp is the pause point, tp is the pause time, and tr is the ramp time, e.g.

pgt-anneal --schedule pr 1.0 0.3 20.0 1.0 # ...

For a boundary cancelation (ramped beta) schedule, specify the primary anneal time with --tf and the schedule parameters with beta <a> <b> <sq>.