Maintenance Release

Compatibility

• Require Python>=3.11 and PyTorch>=2.2 (#3152).
• Require GPyTorch>=1.15.1 (#3181).

New Features

• Efficient leave-one-out cross-validation for Gaussian processes (#3098) and ensemble models (#3103).
• TrajectoryPlanningProblem test problem (#3182).

New Tutorials & Community Notebooks

• Feasibility-driven Trust Region Bayesian Optimization tutorial (#3048).
• HIPE tutorial notebook (#3102).
• Optimization help example notebook (#3148).

Bug Fixes

• Fix the shape of NoisyExpectedHypervolumeMixin._initial_hvs (#3090).
• Fix KroneckerMultiTaskGP.posterior transforming inputs twice (#3132).
• Fix minor bugs in safe_math.py (#3172).

Other Changes

• Make SAAS prior sampleable (#3105).
• Add retries to optimize_with_nsgaii (#3116).
• Allow PosteriorTransform API to optionally accept features X (#3117).
• Clean up get_constants_like usage in botorch/utils/probability (#3131).
• Improve gradient stability in BVN (#3143).
• Enable evaluation of MultiTaskGP with unobserved tasks (#3145).
• Simplify task value remapping API (#3163).
• Update optimize_acqf_homotopy to support mixed optimization (#3165).
• Support custom data covariance modules in SingleTaskMultifidelityGP (#3167).
• Add task-level means to SaasFullyBayesianMultiTaskGP (#3175).
• Use HadamardGaussianLikelihood in HeterogeneousMTGP for inferred noise (#3176).
• Add multi-task mixin support to PyroModel hierarchy (#3177).

Deprecations and Removals

• Remove deprecated APIs for v0.17 (#3134).
  • get_fitted_map_saas_ensemble
  • qMultiObjectiveMaxValueEntropy
  • FullyBayesianPosterior
  • task_feature parameter from SingleTaskGP.construct_inputs
  • fixed_features argument from optimize_acqf_homotopy

Changes to botorch_community

• HIPE acquisition function (#3083, #3108).
• Clamp to 0 to avoid sqrt of negative numbers in mvn_hellinger_distance (#3109).
• Add support for styles to PFN models (#3099, #3114).
• Batched NEI with PFNs, enable more styles in botorch PFNs (#3113).