Merge pull request #1021 from tidymodels/doc-xgboost-mtry-default-value

Document what `mtry = NULL` means for xgboost

Author: hfrick

R/boost_tree.R

@@ -21,7 +21,7 @@
 #'  to use for fitting.
 #' @param mtry A number for the number (or proportion) of predictors that will
 #'  be randomly sampled at each split when creating the tree models
-#' (specific engines only)
+#' (specific engines only).
 #' @param trees An integer for the number of trees contained in
 #'  the ensemble.
 #' @param min_n An integer for the minimum number of data points

man/boost_tree.Rd

@@ -24,6 +24,8 @@ This model has `r nrow(param)` tuning parameters:
 param$item
 ```
 
+For `mtry`, the default value of `NULL` translates to using all available columns.
+
 ## Translation from parsnip to the original package (regression)
 
 ```{r xgboost-reg}

man/parsnip_update.Rd

@@ -25,6 +25,8 @@ This model has 8 tuning parameters:
 
 - `stop_iter`: # Iterations Before Stopping (type: integer, default: Inf)
 
+For `mtry`, the default value of `NULL` translates to using all available columns.
+
 ## Translation from parsnip to the original package (regression)