QAOA Tasks Tutorial

Problem Generation

First, we generate and save all of the random instances of the problem. This is not computationally intensive but very important to do first so we have a fixed set of random instances.

import recirq
from recirq.qaoa.experiments.problem_generation_tasks import \
    SKProblemGenerationTask, HardwareGridProblemGenerationTask, ThreeRegularProblemGenerationTask, \
    generate_3_regular_problem, generate_sk_problem, generate_hardware_grid_problem

pgen_dataset_id = '2020-03-tutorial'
hardware_grid_problem_tasks = [
    HardwareGridProblemGenerationTask(
        dataset_id=pgen_dataset_id,
        device_name='Sycamore23',
        instance_i=i,
        n_qubits=n
    )
    for i in range(5)
    for n in range(2, 8 + 1, 2)
]
recirq.display_markdown_docstring(HardwareGridProblemGenerationTask)

HardwareGridProblemGenerationTask

Generate ‘Hardware Grid’ problems for a named device.

This is a subgraph of the device’s harware topology with random +-1 weights on edges.

See Also

generate_hardware_grid_problem

Attributes

• dataset_id: A unique identifier for this dataset.

• device_name: The device to generate problems for.

• instance_i: Generate random instances indexed by this number.

• n_qubits: Generate an n-qubit instance.

sk_problem_tasks = [
    SKProblemGenerationTask(
        dataset_id=pgen_dataset_id,
        instance_i=i,
        n_qubits=n
    )
    for i in range(5)
    for n in range(3, 7 + 1, 2)
]
recirq.display_markdown_docstring(SKProblemGenerationTask)

SKProblemGenerationTask

Generate a Sherrington-Kirkpatrick problem.

This is a complete (fully-connected) graph with random +-1 weights on edges.

See Also

generate_sk_problem

Attributes

• dataset_id: A unique identifier for this dataset.

• instance_i: Generate random instances indexed by this number.

• n_qubits: Generate an n-qubit instance.

three_regular_problem_tasks = [
    ThreeRegularProblemGenerationTask(
        dataset_id=pgen_dataset_id,
        instance_i=i,
        n_qubits=n
    )
    for i in range(5)
    for n in range(3, 8 + 1) if 3 * n % 2 == 0
]

Run the tasks

for task in hardware_grid_problem_tasks:
    generate_hardware_grid_problem(task)
for task in sk_problem_tasks:
    generate_sk_problem(task)
for task in three_regular_problem_tasks:
    generate_3_regular_problem(task)

Angle Precomputation

from recirq.qaoa.experiments.angle_precomputation_tasks import \
    AnglePrecomputationTask, precompute_angles

apre_dataset_id = '2020-03-tutorial'
precompute_tasks = [
    AnglePrecomputationTask(
        dataset_id=apre_dataset_id,
        generation_task=gen_task,
        p=p)
    for gen_task in recirq.roundrobin(
        hardware_grid_problem_tasks,
        sk_problem_tasks,
        three_regular_problem_tasks,
    )
    for p in range(1, 3 + 1)
]
recirq.display_markdown_docstring(AnglePrecomputationTask)

AnglePrecomputationTask

Pre-compute optimized angles classically for a given problem.

See Also

precompute_angles

Attributes

• dataset_id: A unique identifier for this dataset.

• generation_task: The input task which specifies the problem.

• p: QAOA depth hyperparameter p. The number of parameters is 2*p.

for task in precompute_tasks:
    precompute_angles(task)

Precomputed Angle Data Collection

from recirq.qaoa.experiments.precomputed_execution_tasks import \
    PrecomputedDataCollectionTask, collect_data


dcol_dataset_id = '2020-03-tutorial'
data_collection_tasks = [
    PrecomputedDataCollectionTask(
        dataset_id=dcol_dataset_id,
        precomputation_task=pre_task,
        device_name='Syc23-simulator',
        n_shots=50_000,
        structured=True,
    )
    for pre_task in precompute_tasks
]
recirq.display_markdown_docstring(PrecomputedDataCollectionTask)

PrecomputedDataCollectionTask

PrecomputedDataCollectionTask(dataset_id: str, precomputation_task: recirq.qaoa.experiments.angle_precomputation_tasks.AnglePrecomputationTask, device_name: str, n_shots: int, structured: bool = False, echoed: bool = False)

await recirq.execute_in_queue(collect_data, data_collection_tasks, num_workers=2)

Landscape Data Collection

from recirq.qaoa.experiments.p1_landscape_tasks import \
    P1LandscapeDataCollectionTask, \
    get_data_collection_tasks_on_a_grid, \
    collect_either_landscape_or_cal

recirq.display_markdown_docstring(P1LandscapeDataCollectionTask)

P1LandscapeDataCollectionTask

Collect data for a p=1 landscape

This task does exactly one (beta, gamma) point. You will have to run many of these tasks to get a full landscape

See Also

collect_p1_landscape_data

Attributes

• dataset_id: A unique identifier for this dataset.

• generation_Task: The task specifying the problem to collect data for

• device_name: The device to run on

• n_shots: The number of shots to take

• gamma: The problem unitary parameter gamma

• beta: The driver unitary parameter beta

• line_placement_strategy: Only used for SK model problems. Options include ‘brute_force’, ‘random’, ‘greedy’, ‘anneal’, ‘mst’, and ‘mixed’.

hardware_grid_problem_task = HardwareGridProblemGenerationTask(
    dataset_id=pgen_dataset_id,
    device_name='Sycamore23',
    instance_i=0,
    n_qubits=4
)
data_collection_tasks = get_data_collection_tasks_on_a_grid(
    pgen_task=hardware_grid_problem_task,
    dataset_id=dcol_dataset_id,
    gamma_res=11,
    beta_res=11,
    device_name='Syc23-simulator',
    epoch="grid")

await recirq.execute_in_queue(collect_either_landscape_or_cal,
                              data_collection_tasks,
                              num_workers=2)

sk_problem_task = SKProblemGenerationTask(
    dataset_id=pgen_dataset_id,
    instance_i=0,
    n_qubits=3,
)
data_collection_tasks = get_data_collection_tasks_on_a_grid(
    pgen_task=sk_problem_task,
    dataset_id=dcol_dataset_id,
    gamma_res=11,
    beta_res=11,
    device_name='Syc23-simulator',
    epoch="sk")
await recirq.execute_in_queue(collect_either_landscape_or_cal,
                              data_collection_tasks,
                              num_workers=2)

three_regular_problem_task = ThreeRegularProblemGenerationTask(
    dataset_id=pgen_dataset_id,
    instance_i=0,
    n_qubits=4
)
data_collection_tasks = get_data_collection_tasks_on_a_grid(
    pgen_task=three_regular_problem_task,
    dataset_id=dcol_dataset_id,
    device_name='Syc23-simulator',
    gamma_res=11,
    beta_res=11,
    epoch="tr")

await recirq.execute_in_queue(collect_either_landscape_or_cal,
                              data_collection_tasks,
                              num_workers=2)