* Use explicit template parameter for specifying page type.
* Fix CPU hist init for sparse dataset. * Implement sparse histogram cut. * Allow empty features. * Fix windows build, don't use sparse in distributed environment. * Comments. * Smaller threshold. * Fix windows omp. * Fix msvc lambda capture. * Fix MSVC macro. * Fix MSVC initialization list. * Fix MSVC initialization list x2. * Preserve categorical feature behavior. * Rename matrix to sparse cuts. * Reuse UseGroup. * Check for categorical data when adding cut. Co-Authored-By: Philip Hyunsu Cho <chohyu01@cs.washington.edu> * Sanity check. * Fix comments. * Fix comment.
* Add checks for group size. * Simple docs. * Search group index during hist cut matrix initialization. Co-authored-by: Jiaming Yuan <jm.yuan@outlook.com> Co-authored-by: Philip Hyunsu Cho <chohyu01@cs.washington.edu>
