Commit Graph
32 Commits
Author SHA1 Message Date
swaitsandClaude Opus 4.7 398c82326a feat(compare): add many-objective problems (DTLZ at 4, 10, 8 objectives)
Adds a many-objective section to the comparison harness, exercising the
regime where Pareto dominance stops discriminating: with enough
objectives almost every pair of solutions is mutually non-dominated.

- DTLZ2 4-objective: the entry point to many-objective.
- DTLZ2 10-objective: the curse of dimensionality in full.
- DTLZ1 8-objective: dominance collapse stacked on DTLZ1's deceptive
  multimodal g-term.

Implemented generically: the existing Dtlz1/Dtlz2 structs and distance
metrics are already objective-count agnostic, so a single `ManySpec` +
nine generic runners (RandomSearch, NSGA-II, NSGA-III, MOEA/D, RVEA,
GrEA, IBEA, HypE, AGE-MOEA) cover all three tables -- and any future M.

The results are a clean teaching story:
- NSGA-II collapses -- on DTLZ2-10 it finishes dead last, *worse than
  random search* (2.01 vs 0.63); its crowding distance actively
  misleads in 10-D.
- HypE / MOEA/D / GrEA / IBEA barely notice the 4 -> 10 jump.
- GrEA wins DTLZ1-8, consistent with the 3-objective DTLZ1 table.
- HypE reverses: #1 on both DTLZ2 tables, #6 on the deceptive DTLZ1-8.

Regenerated examples/compare-results.md with the three new sections.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-14 08:56:48 -06:00
swaitsandClaude Opus 4.7 a9d72b94f4 docs: correct disconnected-front and sequencing guidance from compare results
The `compare` harness contradicts two recommendations in the decision
trees:

- "Disconnected or non-convex front -> AGE-MOEA, KnEA, IBEA" had it
  backwards. Added KnEA to the ZDT3 table (the disconnected-front
  benchmark) so the claim is actually exercised: AGE-MOEA and KnEA
  finish *last and second-last*; IBEA wins, MOEA/D and NSGA-II follow.
  The trees now split "disconnected" from "non-convex contiguous",
  lead disconnected with IBEA, and note the geometry-aware methods
  trail when the front is in pieces.
- The book filed Simulated Annealing on permutations as a "one-decision
  baseline" and led the JSS row with GA. On the harness SA *wins* the
  FT06 job-shop table and ties for the TSP optimum; SA/Tabu edge out
  the GA. Reframed SA/Tabu as strong sequencing methods.

Also regenerated examples/compare-results.md for the new ZDT3 row.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-14 08:43:55 -06:00
swaitsandClaude Opus 4.7 2b453464e7 refactor(compare): realign + sort tables, add combinatorial problems
The terminal output was misaligned: headers and data were right-aligned
with hardcoded column widths and separator lengths, and the mean ± std
cells contained the non-ASCII `±` (plus `ε`, `↑`, `↓`) -- on any terminal
that renders those at a non-1 column width the columns drift, and the
hardcoded `-`.repeat(n) separators didn't match the real table width
anyway.

Changes:
- New `print_table` helper: column widths derived from the actual cell
  contents (header + every row), separator length computed to match.
- All table cells are now ASCII: `+/-` instead of `±`, `eps-MOEA`
  instead of `ε-MOEA`, arrows dropped from headers.
- Every table is sorted best-first by its primary quality metric.
- Added three combinatorial / sequencing problems with their own
  (permutation- / bitstring-native) algorithm rosters: a convex-position
  ring TSP (known optimum), FT06 job-shop makespan (known optimum 55),
  and a bi-objective 0/1 knapsack scored by hypervolume.
- Expanded every problem's preamble: what it is, why it's hard, and the
  best-known / optimal result.
- Regenerated examples/compare-results.md to match.

Continuous-problem quality metrics are unchanged (bit-identical to prior
snapshots); only ms columns and row order move.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-14 07:51:12 -06:00
swaits 6aee6d6318 style: rustfmt the Phase 1 test additions
The per-file Phase 1 test commits were written without running rustfmt
as I went; this pass formats the new test code (long assert_eq! lines
wrapped, etc.). Formatting-only — no behavioural change.
2026-05-14 03:41:38 -06:00
swaits ab545e268a docs(examples): add bi-objective TSP crossover-comparison demo
tsp_operators_compare.rs runs NSGA-II four times on the KroAB-25
bi-objective TSP, holding everything constant except the crossover
operator. Ranks OX, PMX, CX, ERX by hypervolume against a fixed
reference point, plus front size, unique-point count, and runtime.

Pedagogical demonstration that the right comparison metric for a
Pareto search is hypervolume, not single-objective fitness.
2026-05-13 19:33:51 -06:00
swaits de463c2214 docs(examples): add bi-objective TSP, 3-objective JSS, and bi-objective knapsack benchmarks
Three harder Pareto-front demos:

- btsp_kroab.rs — Lust-Teghem bi-objective TSP (KroAB-25 subset of
  TSPLIB KroA100/KroB100). NSGA-II with EdgeRecombinationCrossover +
  InversionMutation. Reports hypervolume vs a fixed reference.

- mo_jss_la01.rs — 3-objective JSS on Lawrence LA01 (10x5 instance).
  Objectives: makespan, total flow time, total tardiness (with
  synthetic due dates dj = 1.3 * sum_processing_times(j)). NSGA-III
  with reference_divisions = 12 (91 Das-Dennis points).

- mo_knapsack.rs — bi-objective 0/1 knapsack a la Zitzler-Thiele.
  30 items, two profit vectors, one capacity. NSGA-II with a local
  one-point binary crossover + BitFlipMutation; weight overruns
  penalized in both objectives.
2026-05-13 19:33:45 -06:00
swaits fa499bdb6b docs(examples): add Ulysses16 TSP and FT06 bi-objective JSS benchmarks
Two canonical combinatorial optimization benchmarks demonstrating the
new permutation toolkit:

- tsp_ulysses16.rs — single-objective TSP via GeneticAlgorithm using
  OrderCrossover + InversionMutation. Reaches the known TSPLIB
  optimum (6859) for the 16-city Ulysses GEO-distance instance.

- jss_ft06_bi.rs — bi-objective JSS (makespan + total flow time) on
  the Fisher-Thompson 6x6 benchmark via NSGA-II using a local POX
  crossover + SwapMutation. Makespan corner reaches the known
  single-objective optimum (55).
2026-05-13 19:33:37 -06:00
swaits 729842c260 feat(explorer): JSON export module + supporting metadata + example
Adds a tiny additive surface that turns any OptimizationResult into
a self-describing JSON file the heuropt-explorer webapp can load.
Real Pareto fronts have 50–200+ candidates spanning 2–7+ objectives;
reading them as numbers in a terminal scales badly. This commit
ships the heuropt-side of the explorer — the schema and the export
API. The webapp itself lives in a separate repo on its own cadence.

Three trait/type extensions, all with working defaults so existing
impls compile untouched:

- Objective gains optional `label: Option<String>` and
  `unit: Option<String>` fields, plus fluent builders
  `.with_label("Price").with_unit(\"\$k\")`. Existing
  `Objective::minimize(name)` / `Objective::maximize(name)` are
  unchanged. Both fields are #[serde(default,
  skip_serializing_if = \"Option::is_none\")] so existing JSON
  round-trips cleanly.
- Problem trait gains an optional
  `fn decision_schema(&self) -> Vec<DecisionVariable>` with default
  empty impl. Override it to provide pretty names / labels / units /
  bounds for the explorer; the default produces fallback x[0],
  x[1], … names. New DecisionVariable type at
  `heuropt::core::DecisionVariable` with builder methods.
- New `heuropt::traits::AlgorithmInfo` trait with `name()`
  (required) and `seed()` (default None). Every built-in algorithm
  — all 33 — implements it. Separate from Optimizer<P> so
  multi-fidelity Hyperband (which uses PartialProblem) implements
  it uniformly.

The new explorer module:

- `heuropt::explorer::ExplorerExport` envelope with versioned
  schema (SCHEMA_VERSION = 1).
- ExplorerCandidate per row, with front_rank from
  non_dominated_sort attached at export time so downstream tools
  don't re-derive it.
- ToDecisionValues adapter trait with provided impls for Vec<f64>,
  Vec<bool>, Vec<usize>, Vec<i64>; custom decision types implement
  one method.
- Free functions to_json / to_writer / to_file plus a builder API
  (with_algorithm_info, with_problem_name, with_wall_clock,
  with_timestamp).
- Gated on the existing `serde` feature, which now also pulls in
  `serde_json` as a dep.

The example:

- `examples/pick_a_car.rs` — promotes the README's PickACar to a
  real example, fully enriched with Objective labels/units and a
  decision_schema. Runs NSGA-III for 200 generations, prints a
  sample slice, writes pick_a_car.json. Gated on `serde`.

10 new explorer unit tests cover round-trip serde, fallback
decision-variable names, enriched export, AlgorithmInfo flow,
front-rank correctness, and the ToDecisionValues impls. Lib test
count went from 229 to 242.
2026-05-06 12:48:01 -06:00
swaits af226e3d3b feat: drop heuropt-plot companion crate
Removes the heuropt-plot subcrate, the visualize example that used
it, and the related workspace plumbing (root [workspace] table, the
[workspace] override added to fuzz/Cargo.toml to detach from it,
heuropt-plot dev-dep, CHANGELOG mention).

The visualization concern is better served as an independent third-
party project than as a companion crate in this repo. No effect on
heuropt's public API or the async work in 0.8.0.
2026-05-06 09:04:13 -06:00
swaits 5b5fe50df3 feat(heuropt-plot): v0.1.0 — SVG visualization companion crate
Adds heuropt-plot, a tiny SVG-only plotter that takes heuropt
results and emits scatter plots (pareto_front_svg) and line plots
(convergence_svg). No heavy 'plotters' or 'tiny-skia' dep — hand-
rolled SVG so the crate adds <100 KB to a build.

Workspace setup: root Cargo.toml gains [workspace] with members =
['.', 'heuropt-plot']. heuropt-plot has its own version (0.1.0) and
publishes independently against heuropt 0.8+.

Adds examples/visualize.rs that wires it up: NSGA-II on Schaffer
N.1, plain run() (no observer plumbing), final-front SVG written to
disk.
2026-05-06 07:58:08 -06:00
swaits 6368ca5f3d feat(async): AsyncProblem trait + run_async on RandomSearch and DifferentialEvolution
Adds the headline async/await capability for IO-bound evaluations
(HTTP services, RPC clients, spawned subprocesses) — the
differentiator vs pymoo / hyperopt / MOEA Framework.

No public-API breaks for synchronous users. The new surface is
gated behind a new `async` feature flag.

- core::async_problem::AsyncProblem trait (async fn evaluate_async).
- algorithms::parallel_eval_async::evaluate_batch_async helper using
  futures::stream::FuturesOrdered with concurrency-bounded chunks;
  preserves input order so seeded determinism holds when evaluations
  are themselves deterministic.
- run_async on RandomSearch and DifferentialEvolution.
- examples/async_eval.rs: simulated 20 ms remote service. concurrency=1
  → 4.2 s, concurrency=4 → 2.1 s (2× speedup).

Bumps Cargo.toml to 0.8.0; CHANGELOG entry covers the above plus a
note that 0.6.0/0.7.0 on crates.io are yanked experimentals and 0.8
picks up cleanly from 0.5.
2026-05-06 07:55:56 -06:00
swaits fa3f2e8fb0 feat: v0.5.0 — comprehensive documentation release
Theme: documentation and project polish. No public-API changes; this
is the v0.5 release that elevates heuropt's docs/onboarding/governance
to bar-setting status.

Adds:
- mdbook user guide at docs/book/ with intro, getting-started,
  defining-problems, choosing-an-algorithm, cookbook (7 recipes),
  comparison vs other libraries, stability/SemVer, migration guides.
  Deploys to https://swaits.github.io/heuropt/ via .github/workflows/
  docs.yml.
- Runnable rustdoc examples on every algorithm (35 of them), all
  exercised by cargo test --doc.
- Three real-world examples: portfolio.rs (multi-obj with budget
  constraint), hyperparam_tuning.rs (BO + TPE), scheduling.rs
  (permutation via SA + SwapMutation against Smith's-rule oracle).
- Governance: CONTRIBUTING.md, SECURITY.md, CODE_OF_CONDUCT.md
  (adopting builderscode.org's Builder's Code of Conduct), GitHub
  issue templates, PR template.

Polishes:
- README hero with badges + user-guide link.
- lib.rs crate-level docs.
- CHANGELOG entry for 0.5.0.

Bumps Cargo.toml to 0.5.0.
2026-05-05 14:33:12 -06:00
swaits 232dbc0172 chore(release): bump to v0.4.0
CHANGELOG entry consolidates the unreleased work since v0.3.0:
testing-infrastructure expansion (proptest suites, cargo-fuzz
harness, stability tests, gungraun benches, CI), two real bug
fixes the testing surfaced (NaN-cycle non_dominated_sort, simplex
projection magnitude precision), the README decision-tree update
against the v0.3.0 comparison data, and the v0.4.0 perf pass
(cumulative compare harness 18.6 s → 5.7 s, 3.27×).

`examples/compare-results.md` refreshed with the post-perf-pass
ms numbers; quality metrics are bit-identical to the v0.3.0
snapshot (the perf pass was strictly CPU time, never algorithmic).
2026-05-05 13:28:47 -06:00
swaits 4a59041d1a style: apply rustfmt drift across the crate 2026-05-05 11:40:14 -06:00
swaits 15d3b2752c docs(examples): capture full comparison run output as compare-results.md
Snapshot of `cargo run --release --example compare` after the v0.3.0
algorithm cohort. The harness runs 7 benchmark problems × ~20
algorithms × 10 seeds each (≈3 minutes wall-clock); this file is the
reference output so readers can scan results without running it
themselves.

Highlights worth reading even if you're skipping the file:
- ZDT1: MOPSO and MOEA/D dominate convergence; (1+1)-ES and DE tie
  at f = 0 on Rastrigin
- IPOP-CMA-ES drops vanilla CMA-ES from f=2.35 to f=0.13 on
  Rastrigin (the multimodal failure-mode it was added to fix)
- IBEA wins DTLZ2 (15× closer to true front than NSGA-III)
- GrEA wins DTLZ1 (linear simplex front matches grid-based niching)
- Nelder-Mead = 0 exactly on Rosenbrock; CMA-ES at machine epsilon
- Bayesian optimization at 60 evals is honestly bad on 5-D problems
  with the default kernel — flagged so readers don't conclude BO is
  weak in general; it just needs more evals or hyperparameter tuning
2026-05-05 10:35:05 -06:00
swaits 8a34fd94b8 feat(examples): wire (1+1) ES, Nelder-Mead, IPOP-CMA-ES, BO into compare harness
Adds runners for the four expensive-eval / gradient-free additions to
the appropriate single-objective sections of `examples/compare.rs`:

- Rastrigin (multimodal): now also shows IPOP-CMA-ES alongside vanilla
  CMA-ES so the restart benefit is directly visible.
- Rosenbrock (smooth valley): adds Nelder-Mead (well-suited) and (1+1)
  ES (cheap baseline).
- Ackley + Rosenbrock: BayesianOpt run with a deliberately TINY budget
  (60 evaluations vs 30k for the population-based methods) so the
  sample-efficiency claim is visible — BO with 60 evals vs DE/CMA-ES
  with 30k.

The compare harness now sides-by-sides 23 algorithms total across the
seven benchmark problems.
2026-05-05 09:51:12 -06:00
swaits 60b17f58c9 feat(algorithms): add IpopCmaEs (CMA-ES with restart) for multimodal problems
Auger & Hansen 2005 IPOP-CMA-ES: wraps the existing CmaEs in a restart
loop that doubles the population size and re-randomizes the mean
whenever a restart trigger fires. Specifically addresses the failure
mode we observed on Rastrigin (vanilla CMA-ES = 2.3 vs DE = 0).

Restart triggers:
- The whole budget for one inner CmaEs run finishes without improvement
- (More sophisticated triggers — eigenvalue collapse, condition-number
  blow-up, sigma stagnation — are left for future versions; the
  per-run budget trigger captures the bulk of the practical benefit)

Each restart:
- Doubles the population_size (Auger & Hansen 2005)
- Re-randomizes the initial mean to a fresh point in the bounds box
- Resets sigma to the user's initial value

Same Vec<f64> + single-objective constraints as CmaEs. The total
budget is divided across restarts; restart budget grows with
population. Tests verify it beats vanilla CMA-ES on Rastrigin.
2026-05-05 09:51:12 -06:00
swaits 26385fdb43 feat(examples): add ZDT3, DTLZ1, Rosenbrock, Ackley benchmark problems
Expands the comparison harness with four new test problems chosen for
their distinct geometry:

- **Rosenbrock** (single-obj, smooth valley): the classic non-convex
  smooth function. Differentiates CMA-ES (which exploits the local
  metric) from Rastrigin's multimodal-trap regime.
- **Ackley** (single-obj, exponential multimodal trap): a more
  forgiving multimodal test than Rastrigin — fewer narrow local
  minima — so CMA-ES can show its strength while DE/GA still win.
- **ZDT3** (multi-obj, disconnected front): the only ZDT-family
  problem with a non-contiguous Pareto front. Tests an algorithm's
  ability to maintain spread across gaps.
- **DTLZ1** (many-obj, 3-D linear front): a triangular plane in
  objective space (vs DTLZ2's spherical octant). Different shape
  reveals which many-obj algorithms are biased toward sphere-like
  fronts vs which infer geometry adaptively.

Each new section runs all applicable algorithms × N seeds × the
algorithm-class budget the existing sections already use.
2026-05-05 09:51:12 -06:00
swaits 3400124541 feat(examples): wire SMS-EMOA, HypE, RVEA, PESA-II, ε-MOEA into compare harness
Adds runners for the five new MO algorithms in both the ZDT1 (2-obj)
and DTLZ2 (3-obj) sections of `examples/compare.rs`. The harness now
side-by-sides 11 multi-/many-objective optimizers (RandomSearch + 10
real ones) on each problem.
2026-05-05 09:51:11 -06:00
swaits 7f67e58b27 feat(examples): wire new SO algorithms into the compare harness
Adds runners for HillClimber, SimulatedAnnealing, GeneticAlgorithm,
ParticleSwarm, CmaEs, and Umda to `examples/compare.rs`. Rastrigin
section now compares 8 single-objective optimizers against each other
on a fixed evaluation budget.

The MO sections (ZDT1, DTLZ2) are unchanged for now — MOPSO and IBEA
get added in a follow-up commit so each algorithm's debut shows up
clearly in the harness.
2026-05-05 09:51:11 -06:00
swaits cf3b6acd10 fix(examples): jiggly mean_presses now counts every daily press
The Python tune_runtime.py treats the morning boot press and the 13:00
post-lunch re-tap as 'free' and only counts extra warning-phase taps.
That undercounts what the user actually presses each day and breaks
any comparison against a stated 'presses/day' comfort cap.

Updated `simulate_one` to count every press the user makes:
- boot press at workday start (always +1)
- 13:00 re-login press when the workday continues past lunch (+1)
- per-minute Bernoulli warning-phase presses (already counted)
- death-restart press: each time the device transitions running→dead
  during workday and the user is at-desk (not at lunch), the user
  presses to restart the cycle (warning press and death-restart for
  the same cycle are mutually exclusive — extending via warning press
  prevents that cycle's death)

With baseline now ~2 presses/day already mandatory, the hinge/cap
shift up too: PRESS_HINGE_LOW = 2.5/d (full reward up to baseline +
half a warning press) and PRESS_COMFORT_CAP = 3.5/d (rejected above).

Output 'Why' bullet now reports the total directly and notes the
component breakdown so the number is interpretable against the
new thresholds.
2026-05-05 09:51:10 -06:00
swaits e42514087c feat(examples): personalize jiggly weights with hinge press term and balance bonus
Tweak the a-posteriori scoring to match the user's stated preferences:

- Reweight: lunch_sleep 30%, after_hours 25%, work_fail 20%,
  presses 15% (with hinge below), balance 10%.
- Press term is now a hinge instead of a normalized minimize:
    * <= 2 presses/day → score 1.0 (no penalty)
    * 2 → 3 presses/day → linear ramp from 1.0 to 0.0
    * > 3 presses/day → -inf (excluded; comfort cap)
- New balance term: bonus for longer warning phases. Computed as
  min(YA - RA, RA - FRA), saturated at 10 minutes. So a 5/5/X split
  scores 0.5, an 8/8/X split scores 0.8, and 10/10/X or wider saturates
  at 1.0.

Constants moved to module scope so the printout in main and the
scoring function stay in sync.
2026-05-05 09:51:10 -06:00
swaits 5bd8b571e7 feat(examples): rank the jiggly Pareto front and recommend a pick
Adds an a-posteriori decision step to the jiggly example. After NSGA-III
produces the Pareto front, we apply a weighted-sum score over each
objective normalized to [0, 1] across the front (best→1, worst→0,
direction-aware), and report the top three plus a clear recommendation.

The weights are stated explicitly with rationale, not buried in code:

  work_fail    45%  — screen sleeping mid-meeting is the worst failure
  lunch_sleep  30%  — the actual design goal
  presses      15%  — UX friction the user feels
  after_hours  10%  — minor, mostly screen burn

This is the standard structure for picking a single answer out of a
Pareto set without losing the front itself: someone with different
weights can read the front and pick differently, but we surface a
specific recommendation with reasoning rather than leaving the user
to stare at 84 incomparable rows. Identical normalization could be
swapped for TOPSIS or knee-point detection later if useful.
2026-05-04 20:22:19 -06:00
swaits f70a12010d feat(examples): add jiggly USB-jiggler runtime tuning problem
Port of `scripts/tune_runtime.py` from ~/Code/jiggly: optimize the four
lifecycle constants of a USB mouse-jiggler firmware so the screen sleeps
during the user's lunch hour rather than failing during work.

The Python script grid-searches against a single composite score that
linearly combines several genuinely conflicting goals — a workaround
for the fact that grid search needs one number to rank by. heuropt has
the actual right tool, so this example is structured as a 4-objective
NSGA-III run that surfaces the Pareto front of legitimate tradeoffs:

1. minimize work-time failures (mean_work_sleep)
2. maximize lunch sleep (mean_lunch)
3. minimize human button presses (mean_presses)
4. minimize after-hours waste (mean_after)

Decision: 4-element `Vec<f64>` for (RT, YA, RA, FRA), continuous-relaxed
and rounded to integer minutes inside `evaluate`. The firmware ordering
constraint YA > RA > FRA > 0 is encoded as `constraint_violation` so
heuropt's feasible-beats-infeasible logic handles it for free.

Solver: NSGA-III with M=4, H=6 → 84 reference points, matching the
population size. Each evaluate runs a 1,000-workday Monte Carlo, so
the example is also a deliberately meaty evaluator that benefits from
`--features parallel`.

Output is in jiggly's native units — RT as Xh00m, thresholds in plain
minutes, sleep durations as Xh00m / Mm, probabilities as percentages —
and contrasts the Pareto front against:
- the four extreme single-axis winners (most lunch / fewest work fails /
  fewest presses / least after-hours)
- the firmware's currently-shipping defaults (which sit inside the
  front as a balanced compromise)
2026-05-04 20:16:59 -06:00
swaits ac0274f76f feat(examples): add MOEA/D to ZDT1 and DTLZ2 comparison sections
Two new runners — `zdt1_moead` and `dtlz2_moead` — using the same
SBX + PolyMut variation as the other Pareto-based methods. Reference
divisions chosen so the implied population size is comparable to the
other algorithms in each section (99 → 100 weights for ZDT1; 12 → 91
weights for DTLZ2).
2026-05-04 20:02:54 -06:00
swaits ac1a5856cf chore: fix clippy warnings in NSGA-III, SPEA2, and compare example
- nsga3: drop redundant `.into_iter()` in extend call; use
  `#[allow(clippy::needless_range_loop)]` on the back-substitution
  loop where `j` indexes into the matrix; remove an unneeded
  `return` keyword in a closure.
- spea2: switch `pool.extend(x.drain(..))` to `pool.append(&mut x)`.
- examples/compare.rs DTLZ2 evaluator: same `needless_range_loop`
  silencer on the inner cosine product loop.
2026-05-04 19:59:18 -06:00
swaits 5728ee14e2 feat(examples): add DTLZ2 (3-obj) and NSGA-III to comparison harness
NSGA-III's value over NSGA-II shows up at 3+ objectives, where
crowding distance loses its diversity signal. Adds a third comparison
section to `examples/compare.rs`:

DTLZ2 (3-objective, 12-D, the textbook benchmark for many-objective
algorithms): unit-sphere-octant Pareto front. Compares RandomSearch,
NSGA-II, SPEA2, and NSGA-III on:

- mean distance from front points to the unit sphere
  (closed-form: |1 - sqrt(f1² + f2² + f3²)|),
- spacing,
- front size,
- wall-clock ms.

NSGA-III config: H=12 reference divisions (91 reference points,
matching the canonical setup from Deb & Jain 2014).

Also wires NSGA-III into the existing ZDT1 (2-objective) section even
though it's not its sweet spot — useful as a regression check that the
algorithm at least keeps up with NSGA-II on bi-objective problems.
2026-05-04 19:57:21 -06:00
swaits 18d778a00b feat(examples): add SPEA2 to ZDT1 comparison harness
One-line addition: `zdt1_spea2` runner using bounds-aware operators
(SBX + PolyMut, same hyperparameters NSGA-II uses) and an archive of 100.
2026-05-04 19:53:07 -06:00
swaits 13f126a754 feat(examples): add multi-seed comparison harness
A comparison example that runs every applicable optimizer on ZDT1 and
Rastrigin across N seeds and reports mean ± stddev for each quality
metric. Designed so a new algorithm slots in by adding a single runner
function — no harness changes needed.

ZDT1 (multi-objective, dim=30):
  Reports hypervolume_2d (against ref point [1.1, 1.1]), spacing, mean
  L2 distance to the analytical Pareto front, front size, and wall-clock
  ms. RandomSearch, PAES, and NSGA-II all use bounds-aware operators
  (RealBounds, BoundedGaussianMutation, SBX+PolyMut) so the Problem
  itself stays unclamped — apples-to-apples.

Rastrigin (single-objective, dim=5):
  Reports mean ± stddev best objective and ms. RandomSearch, PAES,
  NSGA-II (degenerate single-obj case), and DE.

Default budget: 10 seeds × 25,000 evaluations on ZDT1, × 50,000 on
Rastrigin. Run with:

  cargo run --release --example compare
2026-05-04 19:51:39 -06:00
swaits 5b1ee99a58 docs(examples): switch ZDT1 to canonical NSGA-II operators (SBX + PolyMut)
Replace the v0.1 `GaussianMutation` + clamp-inside-`evaluate` setup
with the canonical NSGA-II operator pair: SBX (η_c=15, per-var prob 0.5)
followed by PolynomialMutation (η_m=20, per-var prob 1/dim), composed
via `CompositeVariation`. Both are bounds-aware on their own, so the
in-evaluate clamping is dropped.

Result on ZDT1 (dim=30, pop=100, gens=1000, seed=42): mean L2 distance
to the analytical Pareto front is 0.00152 — comfortably within the
published NSGA-II range for this benchmark.

Note on the previous number: the v0.1 setup reported 0.00072 at 40k
evals, but that was an artifact of clamping inside `evaluate`. Out-of-
bounds Gaussian mutations on `x[0]` were snapping to 0, which
coincides with the ZDT1 Pareto-front extreme (f1=0). The new operator
pair has no such free lunch — it runs the actual NSGA-II algorithm —
and the new measurement is what honest convergence on ZDT1 actually
looks like.

Generations bumped from 400 to 1000 (40k → 100k evaluations) to give
the operators headroom; matches the budget DE uses for Rastrigin so
the example feels balanced.
2026-05-04 19:46:56 -06:00
swaits a26849ed13 feat(examples): add ZDT1 and Rastrigin benchmark problems
Two canonical optimization benchmarks in a single runnable example:

- ZDT1 (Zitzler-Deb-Thiele 1): 30-D, two minimization objectives,
  closed-form Pareto front \\(f_2 = 1 - \\sqrt{f_1}\\) for
  \\(f_1 \\in [0, 1]\\). Solved with NSGA-II.
- Rastrigin: highly multimodal single-objective, global minimum
  \\(f = 0\\) at the origin. Solved with DE.

Both are public-domain mathematical formulas. Implemented as Problem
impls in examples/benchmarks.rs; main() runs each, prints front /
best, and (for ZDT1) reports the mean L2 distance from the known
analytical Pareto front so the example doubles as a sanity check on
solution quality.
2026-05-04 19:35:03 -06:00
swaits c58d0241f9 docs(examples): add toy_nsga2, random_search, and custom_optimizer
The three runnable examples called out in spec §18.5 / §19. All open
with `use heuropt::prelude::*;` so they double as a check that the
prelude is sufficient on its own:

- toy_nsga2.rs: Schaffer N.1 solved with NSGA-II.
- random_search.rs: 2D sphere solved with RandomSearch.
- custom_optimizer.rs: a minimal hill-climber implementing
  `Optimizer<P>` directly, demonstrating spec §2.3.
2026-05-04 19:26:54 -06:00