Changelog

[0.2.2] – 6th June 2026

Added

  • added tutorial 19, a finite simulator-scale HHL linear-system solver notebook with exact and inexact phase-estimation sweeps, success probabilities, residual diagnostics, and comparison against the existing QSVT-style inverse workflow

  • committed the rendered tutorial 19 plot artefacts and refreshed the generated tutorial results ledger to include 19 tutorial notebooks

Fixed

  • updated circuit probability execution and resource-summary extraction to use qml.set_shots for finite-shot PennyLane QNodes while constructing devices without deprecated shot arguments

Changed

  • refreshed benchmark timing artefacts and summary tables for the current release environment

  • updated README and results documentation release markers for 0.2.2

[0.2.1] – 6th June 2026

Fixed

  • made QSVT circuit resource-summary extraction compatible with PennyLane versions that return dict-like qml.specs results instead of attribute-only circuit specs

  • narrowed the QSVT circuit execution regression guard so it catches explicit QSVT/block-encoding matrix extraction without blocking PennyLane’s internal single-gate matrix use during angle synthesis

  • stripped trailing whitespace from generated notebook text-output tables so regenerated documentation passes git diff --check

  • committed regenerated tutorial, real-example, and benchmark result pages, plot manifests, and missing notebook plot artefacts needed by the notebook extraction check

Changed

  • refreshed benchmark artefact version metadata and release markers for 0.2.1

[0.2.0] – 6th June 2026

Added

  • added qsvt.execution with execute_qsvt_circuit, a PennyLane QNode execution path that prepares a logical state, queues qml.qsvt, measures statevectors or finite-shot probabilities, and reports circuit resource metadata without calling qml.matrix internally

  • added QSVTCircuitExecutionResult and qsvt_circuit_truth_contract so circuit execution reports distinguish finite QNode execution from dense references and from end-to-end quantum algorithm claims

  • added linear_system_comparison_workflow, LinearSystemComparisonResult, summary-table helpers, and CSV export for comparing dense solves, conjugate gradient, and QSVT-style polynomial inverse workflows on small positive-definite systems

  • added a qsvt linear-system-compare CLI command with JSON report output and optional compact comparison-row CSV output

  • added committed linear-system comparison JSON and CSV artefacts under results/algorithms/ and results/tables/

  • added regression tests that guard the new circuit execution path against falling back to explicit QSVT matrix extraction

  • added tests for the linear-system comparison workflow, CLI command, CSV writer, top-level exports, and committed algorithm artefacts

Changed

  • documented the implementation layers as dense references, small PennyLane matrix verification, and QNode circuit execution

  • expanded linear-system workflow reports with scaled eigenvalue bounds, 2-norm condition numbers, gamma-condition proxies, implementation-kind metadata, and a QSVT-style resource proxy that names omitted quantum layers

  • added explicit implementation_kind fields across high-level algorithm workflow reports to make report scope easier to inspect programmatically

  • updated README, usage, theory, API, algorithm, implementation, resource-model, block-encoding, compatibility, design, physics, notebook, and result documentation for the new execution and comparison surfaces

  • refreshed selected tutorial and real-example notebooks, generated result tables, and benchmark snapshots for the 0.2.0 release

  • updated package metadata and release markers for 0.2.0

[0.1.27] – 2nd June 2026

Changed

  • made the local pre-commit formatting path compatible with running black ., ruff check . --fix, and pytest -q before release commits

  • configured Black to skip notebooks and generated artefact directories so release formatting does not rewrite executed notebook outputs, generated documentation builds, distributions, or result snapshots

  • replaced a nested conditional expression in the linear-system workflow report path with explicit control flow so Black and Ruff agree on the formatted source

  • updated package metadata and release markers for 0.1.27

[0.1.26] – 2nd June 2026

Added

  • added qsvt.block_encoding with explicit finite dense block-encoding construction, top-left block extraction, reconstruction checks, unitarity verification, and JSON-style report helpers

  • added block_encoded_qsvt_workflow for verified finite block-encoded QSVT polynomial transforms on positive Hermitian signal operators, including dense spectral references and optional state-vector diagnostics

  • added a block-encoded Laplacian smoothing real-example notebook using the new package workflow as a near-pure client

  • added tutorial notebooks for finite block-encoded QSVT workflows, sparse operator/oracle assumptions, and QSVT compatibility failure cases

  • added focused documentation pages for block encodings and QSVT compatibility, plus broader theory notes on normalization, Hermitian eigenvalue transforms, QSP phase synthesis, access models, success probability, and readout

Changed

  • improved benchmark notebooks with explicit scope/variable-definition blocks and clearer plots separating classical timings, validation quantities, and QSVT proxy metadata

  • improved selected real-example plots for Anderson localization, harmonic oscillator filtering, and Fermi-Dirac occupations with richer diagnostic panels

  • expanded documentation and notebook indices for the new block-encoding, sparse-assumption, compatibility, and real-example materials

  • updated package metadata and release markers for 0.1.26

[0.1.25] – 2nd June 2026

Added

  • added machine-readable truth_contract metadata to high-level algorithm, direct QSVT verification, resource proxy, and classical benchmark reports so serialized results carry their implementation scope and omitted quantum assumptions

  • added benchmark environment metadata for classical timing snapshots, including Python, NumPy, platform, timer, and timing-stability context

  • documented the report truth contract across the README, usage guide, algorithm, implementation, resource-model, benchmark, and QSVT report pages

  • added a real-problem workflow example showing how to preserve numerical diagnostics and claim-boundary metadata in a saved report

Changed

  • refreshed benchmark, tutorial, and notebook result artefacts after the report schema updates and benchmark timing regeneration

  • tightened tests around report truth contracts, benchmark artefact schema, and QSVT verification report metadata

  • updated package metadata and release markers for 0.1.25

[0.1.24] – 26th May 2026

Added

  • added scripts/update_notebook_results.sh as the local pre-commit helper for executing notebooks, extracting embedded outputs, and regenerating committed notebook result pages

  • documented the committed notebook artefact workflow in the README and results ledger so GitHub Pages publishes committed outputs rather than executing notebooks during deployment

Changed

  • renamed the notebook CI workflow to Notebook result check and removed the scheduled notebook execution trigger

  • changed the GitHub Pages workflow to verify committed notebook result pages and plot manifests without re-executing notebooks before building docs

  • refreshed real-example result page and plot-manifest cell indices so the new committed-artifact verification gate is clean for the release

  • updated package metadata and release markers for 0.1.24

[0.1.23] – 21st May 2026

Added

  • added qsvt examples CLI discovery output for workflow families, benchmark commands, and compact copy-pasteable examples

  • added scripts/release_check.py for local release preflight validation

  • added mypy type-checking configuration, optional type dependencies, and CI type-check coverage for src/qsvt

  • added focused regression coverage for spectral, matrix-construction, and approximation utility modules

Changed

  • enriched QSVT resource proxy reports with explicit proxy metadata, omitted costs, block-encoding/state-preparation flags, and non-fault-tolerant estimate markers

  • tightened NumPy and optional-value annotations across core modules so the package passes mypy src/qsvt

  • raised fast-suite coverage for core utility modules and the package overall

  • updated package metadata and release markers for 0.1.23

[0.1.22] – 20th May 2026

Added

  • added a spectral thresholding workflow for smooth interval-projector studies with exact hard-projector reference diagnostics

  • added qsvt threshold-workflow CLI support with JSON/report output coverage

  • added classical baseline and QSVT resource-model documentation pages

  • added benchmark and tutorial notebooks covering baseline assumptions and block-encoding/resource-proxy limits

Changed

  • refreshed benchmark timing artefacts for the 0.1.22 release snapshot

  • improved classical-baseline notebook outputs with readable tables and benchmark-plot styling consistent with the other benchmark notebooks

  • standardized notebook print and plot labels so normalized examples use conservative units such as model energy units, dimensionless values, states, probabilities, and operator-call counts instead of implying calibrated SI units

  • standardized random notebook examples on an explicit SEED = 0 convention and added a guard against inline notebook RNG seeds

  • refreshed saved outputs for all tutorial, real-example, and benchmark notebooks after the unit-label cleanup

  • expanded API documentation, notebook result pages, and release validation guardrails for the new workflow and artefacts

  • trimmed fast test-suite runtime by reusing lightweight report fixtures, avoiding repeated benchmark construction in formatting tests, and skipping unnecessary notebook JSON parsing during RNG guard checks

  • updated package metadata and release markers for 0.1.22

[0.1.21] – 20th May 2026

Added

  • added classical benchmark baselines for dense eigendecomposition, dense linear solves, conjugate gradient solves, polynomial matrix evaluation, and dense spectral matrix functions

  • added qsvt benchmark CLI subcommands for producing classical benchmark JSON reports from small matrix inputs

  • added public benchmark plotting helpers for classical timings and QSVT resource proxies, with compact stable legend labels

  • added benchmark notebooks under notebooks/benchmarks/ covering linear-system baselines, matrix-function baselines, and scaling sweeps

  • added committed benchmark JSON, CSV, plot, and plot-manifest artefacts under results/benchmarks/, results/tables/, and results/plots/benchmarks/

  • added a generated benchmark notebook output page at docs/qsvt/benchmark_results.md

  • added benchmark artifact integrity tests and notebook execution coverage for benchmark notebooks

Changed

  • extended notebook result extraction and the GitHub Pages workflow preset so tutorial, real-example, and benchmark notebook outputs are refreshed together

  • improved benchmark notebook output readability with indented JSON summaries, clearer plots, stable abbreviations, and markdown notes explaining when QSVT could offer quantum-advantage-relevant scaling

  • updated benchmark, notebook, result, API, README, and usage documentation for the new classical benchmarking workflow

  • updated package metadata and release markers for 0.1.21

[0.1.20] – 19th May 2026

Added

  • added reproducible Matplotlib setup schematics to real-example notebooks, including spin chains, tight-binding chains, PDE domains, transport devices, molecular H2, SSH, bound-state wells, photonic crystals, graphene ribbons, and Chern-insulator lattices

  • added richer real-example plot manifests with notebook titles, plot indices, source cell indices, and PNG dimensions

  • added near-top orientation blocks to every real-example notebook covering the system/problem, QSVT implementation strategy, and quantum relevance

  • added regression coverage for notebook plot-manifest metadata and adaptive result-page image sizing

Changed

  • refreshed real-example notebook outputs and committed PNG artefacts so the rendered result pages now show 53 real-example plots, including setup schematics and quantitative diagnostics

  • improved generated notebook result pages by widening multi-panel figures and cleaning noisy NumPy scalar/array representations in text outputs

  • improved diagnostics report plots with clearer line styling, gridlines, degree metadata, and symmetric residual scaling

  • updated package metadata and release markers for 0.1.20

[0.1.19] – 19th May 2026

Added

  • added generated notebook result pages that display embedded plots and plain-text outputs from every tutorial and real-example notebook

  • added CI checks that verify generated notebook result pages and manifests stay reproducible from committed notebook outputs

  • added GitHub Pages generation that executes notebooks, refreshes notebook result artefacts, and builds docs from the refreshed outputs

Changed

  • renamed the tutorial output page from docs/qsvt/result_gallery.md to docs/qsvt/tutorial_results.md to reflect that it now contains generated notebook outputs rather than a hand-curated gallery

  • improved documentation navigation with a cleaner sidebar grouping, right-hand page tables of contents, result navigation tables, and cross-links between notebook, report, and result pages

  • replaced the docs usage-guide include with a docs-native page so internal links resolve correctly in rendered documentation

  • forced notebook execution through the active python3 kernel during result extraction so CI does not depend on notebook-local kernelspec names

  • updated GitHub Actions workflow dependencies to Node 24-compatible action versions

  • updated package metadata and release markers for 0.1.19

[0.1.18] – 19th May 2026

Added

  • added qsvt design-sweep for compact degree/error/boundedness manifests across polynomial design degrees

  • added committed sign and filter degree-sweep report artefacts plus a machine-readable sweep summary table

  • added deterministic algorithm-workflow regression tests for linear systems, ground-state filtering, Hamiltonian simulation, resolvents, spectral density, and thermal Gibbs workflows

  • added top-level public API status and policy metadata

Changed

  • redesigned rendered results pages around portfolio-style summaries, representative figures, benchmark tables, artefact ledgers, and regeneration commands

  • added rendered algorithm and implementation notes covering workflow targets, diagnostics, rescaling conventions, report serialization, and API scope

  • documented design-sweep in README, usage, diagnostics report, and results documentation

  • updated package metadata and release markers for 0.1.18

[0.1.17] – 19th May 2026

Added

  • added three tutorial notebooks covering end-to-end algorithm workflows, reproducible report/CLI artifacts, and degree/error/boundedness tradeoffs

  • added a topological band-projector real-example notebook using a small Qi-Wu-Zhang lattice model and local Chern-marker diagnostics

Changed

  • updated notebook indexes and README notebook coverage for the expanded tutorial and real-example catalog

[0.1.16] – 19th May 2026

Added

  • added ground_state_filtering_workflow for Gaussian low-energy filtering, filtered-state diagnostics, ground-state overlap, and exact spectral reference comparisons

  • added hamiltonian_simulation_workflow for real-time polynomial evolution with exact unitary/state references and norm-drift diagnostics

  • added resolvent_workflow for Green’s-function / resolvent approximations, optional source-vector responses, and reference error metrics

  • added spectral_density_workflow for Gaussian-window trace density and optional state-resolved spectral weights

  • added thermal_gibbs_workflow for imaginary-time / Boltzmann weighting, normalized Gibbs density matrices, partition functions, and optional weighted-state comparisons

Changed

  • updated package metadata and README release marker for 0.1.16

[0.1.15] – 19th May 2026

Added

  • added qsvt.algorithms.linear_system_workflow, an end-to-end positive-definite linear-system workflow with inverse-polynomial design, spectral rescaling, classical/QSVT solution estimates, residual diagnostics, and compatibility metadata

  • added design_interval_projector_polynomial and design_interval_projector_diagnostics for band-pass spectral filtering and smooth interval projectors on [-1, 1]

  • exposed interval-projector design through design_workflow and the CLI design commands

Changed

  • updated package metadata and README release marker for 0.1.15

[0.1.14] – 19th May 2026

Added

  • added committed real-example plot artefacts under results/plots/real_examples/, with a machine-readable manifest at results/tables/real_examples_plot_manifest.csv

  • added a dedicated notebook execution workflow, .github/workflows/notebooks.yml, for scheduled/manual notebook validation and notebook-sensitive pull requests

  • added .github/workflows/release-check.yml to build documentation with warnings as errors, build distributions, and run twine check before release

  • added the qsvt package py.typed marker and package-data configuration so type checkers can consume the inline annotations

Changed

  • refreshed tutorial notebook plot artefacts using current notebook filenames and updated the rendered tutorial result gallery accordingly

  • split regular CI test execution from notebook execution by marking notebook tests with pytest.mark.notebook

  • refreshed the committed release summary table and documented that the artefacts were refreshed for package version 0.1.14

  • included committed results/ artefacts in source distributions so docs links resolve from packaged archives

Documentation

  • updated RESULTS.md and docs/qsvt/real_example_results.md with the real-example plot ledger, representative gallery, and regeneration commands

  • documented the py.typed marker in the README package map

[0.1.13] – 16th May 2026

Added

  • added five real-world physics example notebooks under notebooks/real_examples/:

    • 24_ising_phase_transition_filtering.ipynb

    • 25_diffusion_heat_treatment_slab.ipynb

    • 26_graphene_nanoribbon_density_of_states.ipynb

    • 27_fermi_dirac_electronic_occupations.ipynb

    • 28_photonic_crystal_band_gap_filtering.ipynb

  • added executable validation cells for the new notebooks covering spin-chain phase diagnostics, thermal diffusion, graphene nanoribbon density of states, Fermi-Dirac occupations, and photonic band-gap filtering

Documentation

  • updated the README, physics workflow guide, notebook index, real-example notebook index, and results index to include the expanded physics examples

  • updated the documented current release to 0.1.13

[0.1.12] – 15th May 2026

Added

  • added committed CLI-generated release artefacts under results/, including design, diagonal QSVT, and Hermitian matrix transform reports

  • added an extracted introductory notebook plot gallery to RESULTS.md

  • added scripts/extract_notebook_plots.py to regenerate notebook plot artefacts from embedded notebook PNG outputs

Changed

  • configured pytest with pythonpath = ["src"] so fresh checkouts can run tests without requiring an editable install first

  • expanded notebook execution coverage to include both introductory notebooks and real physics example notebooks

  • updated the 2x2 linear-solver notebook plot to use real-valued amplitudes explicitly, removing complex-value matplotlib warnings from the test suite

[0.1.11] – 15th May 2026

Documentation

  • refreshed the GitHub Pages landing page and Sphinx/Furo styling to better match the main Sid Richards portfolio site

  • reorganised the documentation sidebar into Start Here, Guides, and Reference sections

  • added first-class Sphinx pages for theory, usage, notebooks, results, and the changelog

  • added RESULTS.md as a notebook result index and convention for future reports, plots, and tables

  • replaced fragile author links in rendered documentation with the main portfolio link

Changed

  • normalised real physics example notebooks with explicit cell IDs for future nbformat compatibility

  • verified all introductory and real physics notebooks execute with nbconvert

[0.1.10] – 15th May 2026

Added

  • added real physics example notebooks under notebooks/real_examples/ covering Hamiltonian simulation, ground-state filtering, quantum chemistry, Green’s functions, spectral density estimation, Gibbs states, PDE linear systems, transport physics, and tensor-network hybrid filtering

  • added qsvt.hamiltonians with reusable small Hamiltonian constructors for tight-binding chains, transverse-field Ising models, Heisenberg chains, and Pauli strings

  • added qsvt.pde with finite-difference Laplacian builders for 1D and 2D PDE examples

  • added qsvt.rescaling for Hermitian spectral normalization and cutoff-based rescaling workflows

  • added qsvt.matrix_functions with polynomial builders for real-time evolution, imaginary-time evolution, resolvents, Gaussian spectral windows, low-energy projectors, and positive inverse workflows

  • added qsvt.diagnostics with reusable state, operator, density-matrix, expectation-value, ground-state-overlap, and spectral-weight metrics

  • added public Chebyshev/monomial basis conversion helpers in qsvt.polynomials

  • added design_positive_inverse_polynomial and design_positive_inverse_diagnostics for positive definite inverse-style workflows

  • added notebook smoke-test coverage for all real physics example notebooks

Changed

  • updated real physics notebooks to use general package APIs instead of local copies of reusable constructors and polynomial builders

  • improved positive inverse design with extension="auto", which compares bounded full-interval extensions and selects the lower sampled error on the positive design interval

  • updated the README, usage guide, API reference, package overview, and docs landing page to document the new physics workflow surface area

Documentation

  • added a dedicated physics workflow guide at docs/qsvt/physics.md

  • added a notebooks/real_examples/README.md mapping major physics areas to executable notebooks

[0.1.9] – 14th May 2026

Changed

  • split the QSVT implementation into focused operator, diagonal, matrix, and compatibility modules while keeping qsvt.qsvt as a compatibility re-export

  • moved CLI command implementation into qsvt.cli, leaving qsvt.__main__ as a small entry point

  • extracted shared Chebyshev fitting, parity projection, and boundedness utilities for design and template builders

  • expanded Ruff checks to include import sorting and bug-prone rule families

Added

  • added qsvt.workflow.design_workflow for returning coefficients, diagnostics, and compatibility metadata from one structured API

  • added a design-workflow CLI command for writing complete design workflow reports from the command line

  • added regression tests for split-module imports, non-power-of-two matrix defaults, complex report serialization, non-finite compatibility inputs, and design workflow results

Documentation

  • documented the new workflow API and split implementation modules in the README and API reference

[0.1.8] – 6th May 2026

Changed

  • fixed Hermitian matrix handling across qsvt.spectral, qsvt.matrices, and qsvt.qsvt so complex Hermitian inputs are preserved instead of being silently cast to real arrays

  • updated non-diagonal QSVT matrix comparison reports to distinguish between real-symmetric comparisons (comparison_basis = "real_part") and full complex Hermitian comparisons (comparison_basis = "full_complex")

  • extended report serialization so complex scalars and arrays are written as JSON-safe {real, imag} payloads

  • updated report-oriented CLI commands so --output and --plot write compact stdout summaries by default, with --print-report available to force full JSON output

  • fixed the package metadata Documentation URL to point at the live GitHub Pages site

  • pruned docs/_build from source distributions and repository export archives for cleaner release artefacts

Documentation

  • updated the README, usage guide, API reference, and report guides to reflect the new CLI output behaviour and complex Hermitian matrix support

  • refreshed the docs landing page styling so the generated site matches the linked portfolio site more closely

[0.1.7] – 23rd April 2026

Changed

  • added non-diagonal Hermitian QSVT matrix transform helpers and reports

  • added a matrix-report CLI command for comparing extracted QSVT blocks with classical spectral polynomial references

  • fixed default matrix QSVT wire selection for embedding block encodings

[0.1.6] – 23rd April 2026

Changed

  • added qsvt.reports helpers for JSON-safe diagnostics payloads, report save/load, and target-vs-polynomial plotting

  • added --output and --plot options to design-report and template-report

  • added qsvt_transform_report for comparing QSVT diagonal transforms with direct classical polynomial evaluation

  • added qsvt_compatibility_report for parity, boundedness, coefficient finiteness, and PennyLane synthesis checks

  • added compare-report and apply-design CLI commands for QSVT transform reports

  • added compatibility-report and design-compatibility CLI commands

  • documented diagnostics report workflows in the README, API reference, and dedicated reports guide

  • cleaned generated local build, test, and lint artifacts after the v0.1.5 release

  • added repository archive attributes for consistent line endings and cleaner generated source archives

  • added source-distribution manifest rules so docs, notebooks, tests, and release notes are included predictably

  • added a package-build CI workflow that runs python -m build and twine check on pushes and pull requests

[0.1.5] – 23rd April 2026

Changed

  • added diagnostics helpers for qsvt.design and qsvt.templates

  • added design-report and template-report CLI commands for JSON approximation-quality reports

  • expanded the markdown docs to cover the new diagnostics surface area

Documentation

  • updated the README to show the report commands and current release

  • documented the report field structure in the API reference

  • added short diagnostics examples to the design and template guides

[0.1.4] – 23rd April 2026

Changed

  • refreshed the release metadata and rebuilt the package for v0.1.4

  • published the 0.1.4 release to PyPI

  • updated the documentation set to cover the newer qsvt.design and qsvt.templates modules more clearly

Documentation

  • expanded the package index to include the full module set

  • cleaned up the API reference module overview and cross-links

  • removed stale citation placeholders from the templates docs

[0.1.3] – 23rd April 2026

Changed

  • intermediate release tag used to validate the automated build and publishing workflow

[0.1.2] – 10th April 2026

Added

New module: qsvt.design

Provides higher-level bounded polynomial construction helpers for common QSVT/QSP design tasks, with outputs returned in standard ascending-degree monomial coefficient form.

Included design helpers:

  • design_inverse_polynomial(gamma, degree)

    • bounded odd inverse-like polynomial

    • approximates the normalized inverse profile gamma / x away from zero

    • intended for linear-solver-style or regularized inverse experiments

  • design_sign_polynomial(gamma, degree)

    • bounded odd sign surrogate

    • useful for spectral sign and threshold-style workflows

  • design_projector_polynomial(gamma, degree)

    • bounded projector-style polynomial based on (1 + sign(x)) / 2

    • useful for positive/negative spectral subspace experiments

  • design_sqrt_polynomial(a, degree)

    • bounded square-root surrogate on a positive interval

    • useful for matrix-function and amplitude-scaling experiments

  • design_power_polynomial(alpha, degree, a=0.0)

    • bounded positive-power surrogate on a positive interval

    • useful for simple spectral shaping workflows

  • design_filter_polynomial(cutoff, degree)

    • bounded even soft-threshold filter

    • useful for singular-value filtering and smooth pass/reject experiments

Implementation notes

  • reuses the existing lightweight Chebyshev fitting helper in qsvt.approximation

  • converts fitted Chebyshev polynomials back to ascending monomial coefficients

  • numerically enforces boundedness on [-1, 1] by rescaling when necessary

  • enforces odd/even parity where structurally appropriate

  • keeps implementations NumPy-only and notebook-friendly

Tests

Added minimal smoke tests covering:

  • construction of all design helpers

  • boundedness on [-1, 1]

  • expected parity for inverse/sign/filter builders

  • basic qualitative behaviour checks for inverse/sign/projector/sqrt/power

Public API

Updated qsvt.__init__ to export the new design helpers.

[0.1.1] – 10th April 2026

Added

New module: qsvt.templates

Provides ready-to-use bounded polynomial templates for QSVT/QSP-style experiments, returned in standard ascending-degree coefficient form.

Included template families:

  • inverse_like_polynomial

    • smooth bounded odd inverse-like surrogate on [-1, 1]

    • useful for regularised small-scale linear-solver style experiments

  • sign_approximation_polynomial

    • smooth odd sign surrogate based on a steep bounded transition

    • useful for spectral sign and projector-style workflows

  • soft_threshold_filter_polynomial

    • even soft pass/reject filter based on |x|

    • useful for singular-value filtering intuition and threshold experiments

  • sqrt_approximation_polynomial

    • bounded square-root-like template on the canonical interval

    • useful for matrix-function and amplitude-scaling experiments

  • exponential_approximation_polynomial

    • bounded exponential-like weighting polynomial

    • useful for smooth spectral damping and low-degree filter examples

Implementation notes

  • templates are constructed via lightweight Chebyshev fitting on [-1, 1]

  • outputs are converted back to standard monomial coefficients

  • boundedness on [-1, 1] is enforced numerically by rescaling if needed

  • odd/even parity is enforced where appropriate for sign/inverse/filter families

Tests

Added minimal smoke tests covering:

  • template construction

  • boundedness on [-1, 1]

  • expected parity for odd/even templates

  • basic qualitative behaviour checks

Public API

Updated qsvt.__init__ to export the new template builders and bumped the package version to 0.1.1.

[0.1.0] – 10th April 2026

Added

Core package structure under src/qsvt/:

  • polynomials.py

    • Chebyshev polynomial utilities

    • polynomial evaluation helpers

    • parity detection and coefficient utilities

  • approximation.py

    • Chebyshev-based bounded polynomial approximation

    • domain scaling helpers for mapping intervals to [-1,1]

    • approximation error utilities (max error, RMS error)

    • callable approximant construction

  • matrices.py

    • small Hermitian matrix constructors

    • rotation matrices and rotated diagonal matrices

    • involutory diagonal matrices (±1 spectra)

    • helper utilities for vector normalisation and embedding

  • spectral.py

    • classical spectral matrix-function utilities

    • eigendecomposition helpers

    • matrix powers and fractional powers

    • matrix sign function

    • spectral projectors onto positive/negative eigenspaces

    • polynomial transforms applied via eigenspectrum

  • qsvt.py

    • thin PennyLane QSVT wrapper layer

    • scalar QSVT helpers (QSP-equivalent behaviour)

    • explicit unitary extraction via qml.matrix

    • logical top-left block extraction utilities

    • diagonal singular value transform helpers

    • classical vs QSVT comparison utilities

    • embedded-vector QSVT workflows

  • __init__.py

    • curated public API surface

    • version exposure via __version__

  • __main__.py

    • lightweight CLI entry point

    • scalar QSVT evaluation

    • diagonal singular-value transformation

    • Chebyshev polynomial evaluation

    • JSON-formatted output

    • numpy-safe serialization

CLI

Added console script:


qsvt

Example usage:


qsvt scalar --x 0.5 --poly "0,0,1"

qsvt diag 
--values "1.0,0.7,0.3,0.1" 
--poly "0,0,1" 
--wires 3

qsvt cheb --degree 3 --x 0.5

Packaging

  • Added pyproject.toml

  • configured setuptools backend

  • package layout uses src/ structure

  • editable installs supported (pip install -e .)

  • console script entry point configured

  • Python ≥3.10 supported

Tests

  • added smoke tests for core functionality:

    • Chebyshev polynomial evaluation

    • polynomial parity detection

    • scalar QSVT correctness

    • diagonal QSVT correctness

Documentation

  • updated README.md to include:

    • PyPI installation instructions

    • CLI usage examples

    • package module overview

    • relationship between notebooks and reusable code

Scope

Initial release focuses on:

  • educational clarity

  • explicit small-scale QSVT demonstrations

  • classical reference implementations

  • minimal abstraction over PennyLane primitives

No circuit optimisation, amplitude amplification, or hardware resource estimation included.