Changes

💡 New Features

• [R-package] {lightgbm} is now available on CRAN (fixes #629) @jameslamb (#3612)
• [R-package] Use command-line args to customize CMake builds (fixes #2441) @jameslamb (#3574)
• [python] Allow to build Python wheel package @dolfinus (#3594)

🚀 Efficiency Improvement

• [R-package] use as.factor() instead of factor() in lgb.cv() @jameslamb (#3560)

🐛 Bug Fixes

• [R-package] fix partial matching of keyword arguments in lgb.cv() (fixes #3629) @jameslamb (#3630)
• fix typo in dataset checks @StrikerRUS (#3631)
• Check max_bin, etc. match config when using binary @cyfdecyf (#3592)
• [R-package] construct dataset earlier in lgb.train and lgb.cv (fixes #3583) @tonyk7440 (#3598)
• [python] fix regex in MANIFEST file @StrikerRUS (#3593)
• Fix #3557 and potential issue with dense multi-val feature groups. @shiyu1994 (#3590)
• fix deterministic, part2 @guolinke (#3578)
• remove max_block_size_ in train states (fix #3570) @shiyu1994 (#3575)

📖 Documentation

• [python] more detailed docs for trees_to_dataframe(), create_tree_digraph(), plot_tree() @jameslamb (#3618)
• [docs] update documentation with AUC-mu, average precision @jameslamb (#3627)
• [docs] Add new badges @StrikerRUS (#3610)
• [docs][R-package] fix typo @StrikerRUS (#3609)
• [docs] add link to lightgbm4j to readme @shuttie (#3597)

🧰 Maintenance

• release 3.1.1 @jameslamb (#3611)
• [ci] add credentials to gitignore @jameslamb (#3620)
• [R-package] Update remaining internal function calls to use keyword arguments @zenggyu (#3617)
• [R package] update lgb.Dataset.R to use keyword arguments @zenggyu (#3607)
• [R-package] Update lgb.model.dt.tree.R to use keyword arguments @zenggyu (#3605)
• [R-package] use keyword arguments for internal functions in utils.R @mfrasco6 (#3604)
• [ci] remove unnecessary environment variables in R-package CI @jameslamb (#3602)
• [R-package][tests] update values in valgrind test @StrikerRUS (#3600)
• [refactor] Reduce code duplication in c_api.cpp @AlbertoEAF (#3539)
• [refactor] SWIG - Split pointer manipulation to individual .i file @AlbertoEAF (#3538)
• [ci] test 32-bit R in CI @jameslamb (#3588)
• [ci] Fix missing git install in R artifact job (fixes #3567) @jameslamb (#3587)
• [R-package] Remove CLI-only objects @jameslamb (#3566)
• small R Docker cleanup @StrikerRUS (#3582)
• [python] remove unnecessary files to reduce sdist size @jameslamb (#3579)
• bump version for development @guolinke (#3568)
• [ci] remove conda from R CI jobs @jameslamb (#3573)