This is the release note of v3.5.0.

Highlights

This is a maintenance release with various bug fixes and improvements to the documentation and more.

Breaking Changes

• Isolate the fast.ai module from optuna (optuna/optuna-integration#49, thanks @sousu4!)
• Change n_objectives condition to be greater than 4 in candidates functions (#5121, thanks @adjeiv!)

New Features

• Support constraints in plot contour (#4975, thanks @y-kamiya!)
• Support infeasible coloring for plot_timeline (#5014)
• Support constant_liar in multi-objective TPESampler (#5021)
• Add optuna study-names cli (#5029)
• Use ExpectedHypervolumeImprovement candidates function for BotorchSampler (#5065, thanks @adjeiv!)
• Fix logei_candidates_func in botorch.py (#5094, thanks @sousu4!)
• Report CV scores from within OptunaSearchCV (#5098, thanks @adjeiv!)

Enhancements

• Support constant_liar in multi-objective TPESampler (#5021)
• Make positional args to kwargs in suggest_int (#5044)
• Ensure n_below is never negative in TPESampler (#5074, thanks @p1kit!)
• Improve visibility of infeasible trials in plot_contour (#5107)

Bug Fixes

• Fix random number generator of NSGAIIChildGenerationStrategy (#5003)
• Return trials for above in MO split when n_below=0 (#5079)
• Enable loading of read-only files (#5103, thanks @Guillaume227!)
• Fix logpdf for scaled truncnorm (#5110)
• Fix the bug of matplotlib's plot_rank function (#5133)

Documentation

• Add the table of dependencies in each integration module (#5005)
• Enhance the documentation of LightGBM tuner and separate train() from __init__.py (#5010)
• Update link to reference (#5064)
• Update the FAQ on reproducible optimization results to remove note on HyperbandPruner (#5075, thanks @felix-cw!)
• Remove MOTPESampler from index.rst file (#5084, thanks @Ashhar-24!)
• Add a note about the deprecation of MOTPESampler to the doc (#5086)
• Add the TPE tutorial paper to the doc-string (#5096)
• Update README.md to fix the installation and integration (#5126)
• Clarify that Recommended budgets include n_startup_trials (#5137)

Examples

• Update version syntax for PyTorch and PyTorch Lightning examples (optuna/optuna-examples#205, thanks @JustinGoheen!)
• Update import path (optuna/optuna-examples#213)
• Bump up python versions (optuna/optuna-examples#214)
• Add the simplest example directly to README (optuna/optuna-examples#215)
• Add simples examples for multi-objective and constrained optimizations (optuna/optuna-examples#216)
• Revise the comment to describe the problem (optuna/optuna-examples#217)
• Modify simple examples based on the Optuna code conventions (optuna/optuna-examples#218)
• Remove version specification of jax and jaxlib (optuna/optuna-examples#223)
• Import examples from optuna/optuna-dashboard (optuna/optuna-examples#224)
• Add OptunaSearchCV with terminator (optuna/optuna-examples#225)
• Drop python 3.8 from haiku test (optuna/optuna-examples#227)
• Run MXNet in Python 3.11 (optuna/optuna-examples#228)

Tests

• Remove tests for allennlp and chainer (optuna/optuna-integration#47)
• Reduce the warning in tests/study_tests/test_study.py (#5070, thanks @sousu4!)

Code Fixes

• Implement NSGA-III elite population selection strategy (#5027)
• Fix import path of PyTorchLightning (#5028)
• Fix Any with float in _TreeNode.children (#5040, thanks @aanghelidi!)
• Fix future annotation in typing.py (#5054, thanks @jot-s-bindra!)
• Add future annotations to callback and terminator files inside terminator folder (#5055, thanks @jot-s-bindra!)
• Fix future annotations to edf python file (#5056, thanks @Vaibhav101203!)
• Fix future annotations in _hypervolume_history.py (#5057, thanks @Vaibhav101203!)
• Reduce the warning in tests/storages_tests/test_heartbeat.py (#5066, thanks @sousu4!)
• Fix future annotation to frozen.py (#5080, thanks @Vaibhav101203!)
• Fix annotation for dataframe.py (#5081, thanks @Vaibhav101203!)
• Fix future annotation (#5083, thanks @Vaibhav101203!)
• Fix type annotation (#5105)
• Fix mypy error in CI (#5106)
• Isolate the fast.ai module (#5120, thanks @sousu4!)
• Clean up workflow file (#5122)

Continuous Integration

• Run test_tensorflow in Python 3.11 (optuna/optuna-integration#46)
• Exclude mypy checks for chainer (optuna/optuna-integration#48)
• Support Python 3.12 on tests for core modules (#5018)
• Fix the issue where formats.sh does not handle tutorial/ (#5023, thanks @sousu4!)
• Skip slow integration tests (#5033)
• Install PyTorch for CPU on CIs (#5042)
• Remove unused type: ignore (#5047)
• Reduce tests-mpi to the oldest and latest Python versions (#5067)
• Add workflow matrices for the tests to reduce GitHub check runtime (#5093)
• Remove the skip of Python 3.11 in tests-mpi (#5100)
• Downgrade kaleido to 0.1.0post1 for fixing Windows CI (#5101)
• Rename should-skip to test-trigger-type for more clarity (#5134)
• Pin the version of PyQt6-Qt6 (#5135)
• Revert Pin the version of PyQt6-Qt6 (#5140)

Other

• Bump up version to v3.5.0.dev (optuna/optuna-integration#43)
• Bump up version number to 3.5.0 (optuna/optuna-integration#52)
• Bump the version up to v3.5.0.dev (#5032)
• Remove email of authors (#5078)
• Update the integration sections in README.md (#5108)
• Pin mypy version to 1.6.* (#5123)
• Remove !examples from .dockerignore (#5129)

Thanks to All the Contributors!

This release was made possible by the authors and the people who participated in the reviews and discussions.

@Alnusjaponica, @Ashhar-24, @Guillaume227, @HideakiImamura, @JustinGoheen, @Vaibhav101203, @aanghelidi, @adjeiv, @c-bata, @contramundum53, @eukaryo, @felix-cw, @gen740, @jot-s-bindra, @keisuke-umezawa, @knshnb, @nabenabe0928, @not522, @nzw0301, @p1kit, @sousu4, @toshihikoyanase, @y-kamiya