GitLab

* Callback for NA handling

* lgb.Booster default score => NA

* lgb.cv default best score => NA

* Fix back callback

* lgb.train with booster check at the end

manual tests done: 
* With early stopping + with validation set
* With early stopping + without validation set
* Without early stopping + with validation set
* Without early stopping + without validation set

And with multiple metrics / validation sets.

* lgb.cv with booster check at the end

manual tests done: 
* With early stopping + with validation set
* With early stopping + without validation set
* Without early stopping + with validation set
* Without early stopping + without validation set

And with multiple metrics / validation sets.

* [R-package] removed horizontal whitespace (fixes #1642)

* [R-package] fixed missing newline in test file

* Fixed typos in docs

* Fixed inconsistencies in documentation

* Updated strategy for registering routines

* Fixed issues caused by smashing multiple functions into one Rd

* Fixed issues with documentation

* Removed VignetteBuilder and updated Rbuildignore

* Added R build artefacts to gitignore

* Added namespacing on data.table set function. Updated handling of CMakeLists file to get around CRAN check.

* Updated build instructions

* Added R build script

* Removed build_r.sh script and updated R-package install instructions

* fix early stopping edge case

* fix message.

* fix tests

* fix GPU tests.

fix typos in callback.R and lgb.cv.R, closing #946 and #947

* minor changes for robustness and efficiency

* fix charcter typo

* don't use lgb.is.* in filter

* revert to cat instead of message; don't use mget

* fix bugs in previous commits

* should be good to go now

* Try to store best scores in R package Microsoft/LightGBM#686

* Add binding for best_score (unlock environment)

* Fix double comma

* Add best_score to lgb.Booster

* Define environment in examples (xgboost clash)

* Large R code changes

* src & callbacks

* lgb.Booster and utils

* cv

* wip lgb.Dataset

* lgb.Dataset

* lgb.Predictor

* lgb.train

* typos

* add flags to facilitate macosx compilation

* fix basic_string template error with clang

* most unfortunate mode of development

* fixup tests

* last test

* roxygen

* roxygen v5.x.x

* finish R's c_api

* clean code

* fix sizeof pointer in 32bit system.

* add predictor class

* add Dataset class

* format code

* add booster

* add type check for expose function

* add a simple callback

* add all callbacks

* finish the basic training logic

* update docs

* add an simple training interface

* add basic test

* adapt the changes in c_api

* add test for Dataset

* add test for custom obj/eval functions

* fix python test

* fix bug in metadata init

* fix R CMD check