v0.5.0

Link to Release PR - #238

🛠️ Core Framework Improvements

Custom Repertoire Integration (#222)

• Allow MAPElites to be built with any repertoire by passing custom repertoire init functions
• Default behavior maintained with MapElitesRepertoire.init
• Enhanced flexibility for custom repertoire implementations

MAPElites Repertoire Enhancement (#211)

• Enhanced MAPElitesRepertoire to store any kind of information through improved extra_scores handling
• Standardized extra scores management across all repertoire classes with keys_extra_scores parameter
• Added filter_extra_scores method to filter extra scores based on keys
• Moved observations from dedicated fields to extra_scores storage

Ask/Tell Interface (#221)

• New user-facing ask/tell interface for more flexible algorithm interaction
• Added init_ask_tell function for initialization without scoring functions
• Refactored update functions to use ask/tell internally, reducing code duplication

🔄 Major Refactoring & Architecture Changes

Selector System Overhaul (#209)

• New unified selection interface through the Selector abstraction for improved modularity and extensibility
• Introduced UniformSelector and MOMEUniformSelector implementations
• Selectors now return full sub-repertoires instead of just genotypes, eliminating the need for multiple sampling functions
• Default selection behavior integrated into repertoire classes

Brax Environment Structure Reorganization (#236)

• Complete restructuring of Brax-related code from /environments to /tasks/brax with proper versioning
• Added Brax v2 support alongside existing Brax v1
• Improved environment handling and version management

Code Organization (#200, #204)

• Moved cmaes.py from core to baselines for better module organization

🔧 Code Quality & Standards

Terminology Standardization (#190)

• Unified descriptor naming from mixed "bd", "BD", "behavior_descriptor" to consistent "descriptor"
• Stopped returning random keys following JAX best practices
• Renamed all random_key parameters to key
• Removed deprecated Brax scoring functions
• Standardized unused parameter naming with underscore prefix

JIT Compilation Cleanup (#232)

• Removed individual jax.jit decorators from internal functions for more user coding flexibility
• Improved function signatures

JAX Modernization (#195)

• Updated to new-style JAX random keys (jax.random.key instead of jax.random.PRNGKey)
• Full compliance with JAX JEP 9263 typed keys specification

⚡ Performance & Memory Optimizations

VRAM Optimization (#224)

• Significant memory improvements in PGA and DCRL algorithms
• Off-spring PG mutations now share mini-batches, reducing memory usage
• Step-by-step transition sampling in both "emit_pg" and "state_update"
• Simplified function structure and combined training/update operations
• New scan_actor_critic_training function for efficient Actor-Critic loops

🔍 Quality Assurance

Automated Spell Checking (#194)

• Added codespell pre-commit hook to catch typos automatically
• Fixed existing typos throughout codebase
• Updated pre-commit configuration with latest package versions

Updated example notebooks with better parameter handling for NSGA-II and SPEA2 (#231)

• Fixed batch size parameters to use population_size by default for genetic algorithms

📊 Metrics & Analysis Features

Uncertainty Domain Support (#186)

• New reevaluation functions in qdax/utils/uncertain_metrics.py
• Compute corrected archives for uncertain domains
• Comprehensive test coverage for uncertainty metrics

Enhanced Visualization (#233)

• Custom x-axis labels in plot_map_elites_results
• Defaults to "Environment steps" with backward compatibility

Metrics Initialization (#214)

• Return metrics after repertoire initialization for better monitoring

🧹 Cleanup & Maintenance

Simplified Interface (#225)

• Removed save and load methods from repertoire classes
• Users can now use custom serialization methods like pickle or orbax
• Reduced maintenance burden for new repertoire types

Package Configuration Modernization (#213)

• Migrated from setup.py to pyproject.toml for modern Python packaging standards

Fixed indexing in UnstructuredRepertoire (#185)

• better handling of NaN descriptors

Legacy spring support (#226)

• Legacy spring support for Brax v1 with backward compatibility boolean flag