Add base representation of `SparseObservable` #12671

jakelishman · 2024-06-26T17:24:58Z

Summary

This adds the base representation of SparseObservable, including the simple constructors from Python space and the ability to view the data buffers.

This commit does not include the mathematical manipulations of the operators, nor some of the helper methods that will be used to manipulate the operators in the context of primitives execution. These will follow in subsequent patches.

The design and implementation notes of SparseObservable are described in a Qiskit RFC that preceeded this patch series¹, and it's best to consult that document for full details on the operator considerations.

Details and comments

This is the beginnings of the implementation of Qiskit/RFCs#74, and subject to change based on decisions made there.

A current simple example of what works with the PR:

import numpy as np
from qiskit.quantum_info import SparseObservable

# Using the copy-in constructor to make the Z_0 + Z_1 + Z_2 + ... operator
# by manually providing the data buffers.
num_qubits = 100
terms = np.full((num_qubits,), SparseObservable.BitTerm["+"], dtype=np.uint8)
indices = np.arange(num_qubits, dtype=np.uint32)
coeffs = np.ones((num_qubits,), dtype=complex)
boundaries = np.arange(num_qubits + 1, dtype=np.uintp)
# This copies out of the buffers, because we need the base allocations to be
# owned by Rust space.
so = SparseObservable.from_raw_parts(num_qubits, coeffs, terms, indices, boundaries)

print(so.bit_terms)

This PR depends on #12669.

Close #12282. This PR only adds the representation of such operators, but that's sufficient to immediately fulfil the feature as an MVP. Qiskit/RFCs#75 tracks the rest of the implementation of the RFC.

https://github.com/Qiskit/RFCs/blob/7a74b08793475b7b0142d3a3f7142cabcfd33ab8/0021-sparse-observable.md ↩

jakelishman · 2024-07-16T16:42:51Z

No longer "on hold" because its dependency merged, but I do still need to write a lot more of the initialisation methods for this.

qiskit-bot · 2024-10-01T13:54:50Z

One or more of the following people are relevant to this code:

@Qiskit/terra-core

jakelishman · 2024-10-01T13:55:39Z

This base PR for SparseObservable is now ready for review. I'll follow it (at some point) with another adding mathematical operators to the observable, and one (or more) adding helper methods for use by and for the primitives.

coveralls · 2024-10-01T14:19:20Z

Pull Request Test Coverage Report for Build 11458543910

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

For more information on this, see Tracking coverage changes with pull request builds.
To avoid this issue with future PRs, see these Recommended CI Configurations.
For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

710 of 725 (97.93%) changed or added relevant lines in 4 files are covered.
13 unchanged lines in 3 files lost coverage.
Overall coverage increased (+0.08%) to 88.634%

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
crates/accelerate/src/sparse_observable.rs	707	722	97.92%

Files with Coverage Reduction	New Missed Lines	%
qiskit/transpiler/passes/synthesis/unitary_synthesis.py	2	61.59%
crates/qasm2/src/lex.rs	5	92.23%
qiskit/synthesis/two_qubit/xx_decompose/decomposer.py	6	90.77%

Totals
Change from base Build 11411236768:	0.08%
Covered Lines:	74571
Relevant Lines:	84134

💛 - Coveralls

jakelishman · 2024-10-02T13:56:28Z

The only missing lines in the coverage report are ones that are unreachable, either clearly from the code, or because they're error paths to handle things like a SparsePauliOp that violates its internal data structures during the extraction of the data to Rust space.

(Also there's a line about copy=False in an __array__ method, but that actually is tested, it's just the coverage run uses numpy<2 due to some transitive dependency, which suppresses that test.)

This adds the base representation of `SparseObservable`, including the simple constructors from Python space and the ability to view the data buffers. This commit does not include the mathematical manipulations of the operators, nor some of the helper methods that will be used to manipulate the operators in the context of primitives execution. These will follow in subsequent patches. The design and implementation notes of `SparseObservable` are described in a Qiskit RFC that preceeded this patch series[^1], and it's best to consult that document for full details on the operator considerations. [^1]: https://github.com/Qiskit/RFCs/blob/7a74b08793475b7b0142d3a3f7142cabcfd33ab8/0021-sparse-observable.md

Cryoris

I'm not quite through with the first look, but there's some bits I don't 100% understand (like how bytemuck works) but overall this looks really nice and the the comments help a ton to understand it 🙂 I have mainly questions below for now and will have a look at the rest (and play with it) in a bit!

crates/accelerate/src/sparse_observable.rs

Co-authored-by: Julien Gacon <[email protected]>

Cryoris

Thanks for the detailed comments and responses, this looks really nice (and I learned quite a bunch in reviewing 😄)!

jakelishman added this to the 1.2.0 milestone Jun 26, 2024

jakelishman force-pushed the sparse-observable branch 2 times, most recently from 4dce391 to acd7d56 Compare June 26, 2024 17:31

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jakelishman force-pushed the sparse-observable branch from acd7d56 to 0fa4a90 Compare July 3, 2024 13:33

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1ucian0 mentioned this pull request Jul 9, 2024

Epic - Implementation of RFC 0021: Sparse observables with extended alphabets Qiskit/RFCs#75

Open

3 tasks

jakelishman removed the on hold Can not fix yet label Jul 16, 2024

t-imamichi mentioned this pull request Jul 17, 2024

Make SamplerPub and EstimatorPub public #12222

Open

ihincks mentioned this pull request Jul 17, 2024

Add Observable container type for Estimator #11594

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ElePT mentioned this pull request Jul 24, 2024

Add ObservablesArray.apply_layout() #12221

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mtreinish modified the milestones: 1.2.0, 1.3 beta Jul 25, 2024

mtreinish modified the milestones: 1.3 beta, 1.3.0 Sep 5, 2024

jakelishman force-pushed the sparse-observable branch 2 times, most recently from 641d87f to 83ca5a9 Compare October 1, 2024 13:53

jakelishman marked this pull request as ready for review October 1, 2024 13:54

jakelishman requested a review from a team as a code owner October 1, 2024 13:54

jakelishman changed the title ~~WIP: Add base representation of SparseObservable~~ Add base representation of SparseObservable Oct 1, 2024

jakelishman force-pushed the sparse-observable branch from 83ca5a9 to 50319a5 Compare October 2, 2024 13:27

jakelishman assigned Cryoris Oct 2, 2024

jakelishman force-pushed the sparse-observable branch from 50319a5 to d88dce5 Compare October 8, 2024 17:47

jakelishman mentioned this pull request Oct 8, 2024

Implement arithmetic on SparseObservable #13298

Merged

Cryoris reviewed Oct 18, 2024

View reviewed changes

jakelishman and others added 7 commits October 18, 2024 20:20

Rename num_ops to num_terms

4ca948e

Fix typos and 🇺🇸

34a5490

Co-authored-by: Julien Gacon <[email protected]>

Add additional documentation

9dd0187

Merge remote-tracking branch 'ibm/main' into sparse-observable/repr

ae05696

Fix tests of num_terms

598930e

Add more documentation

94ab2d6

Fix error-message typo

e064c87

Co-authored-by: Julien Gacon <[email protected]>

Cryoris approved these changes Oct 22, 2024

View reviewed changes

Cryoris added this pull request to the merge queue Oct 22, 2024

Merged via the queue into Qiskit:main with commit 548c857 Oct 22, 2024
16 checks passed

jakelishman deleted the sparse-observable branch October 22, 2024 12:54

jakelishman mentioned this pull request Nov 1, 2024

Add "layout" to the SparsePauliOp (and related operators) #11891

Closed

mtreinish mentioned this pull request Nov 15, 2024

Add C API for SparseObservable #13445

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Add base representation of `SparseObservable` #12671

Add base representation of `SparseObservable` #12671

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Add base representation of SparseObservable #12671

Add base representation of SparseObservable #12671

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jakelishman commented Jun 26, 2024 • edited Loading

Summary

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Pull Request Test Coverage Report for Build 11458543910

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Add base representation of `SparseObservable` #12671

Add base representation of `SparseObservable` #12671

jakelishman commented Jun 26, 2024 •

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coveralls commented Oct 1, 2024 •

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jakelishman commented Oct 2, 2024 •

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