document a little more for sparse matrix input

Author: EmilHvitfeldt

NEWS.md

@@ -1,5 +1,6 @@
 # parsnip (development version)
 
+* `fit_xy()` can now take dgCMatrix input for `x` argument (#1121).
 
 * `fit_xy()` currently raises an error for `gen_additive_mod()` model specifications as the default engine (`"mgcv"`) specifies smoothing terms in model formulas. However, some engines specify smooths via additional arguments, in which case the restriction on `fit_xy()` is excessive. parsnip will now only raise an error when fitting a `gen_additive_mod()` with `fit_xy()` when using the `"mgcv"` engine (#775).
 

R/fit.R

@@ -55,6 +55,11 @@
 #' a "reverse Kaplan-Meier" curve that models the probability of censoring. This
 #' may be used later to compute inverse probability censoring weights for
 #' performance measures.
+#' 
+#' Sparse data is supported, with the use of the `x` argument in `fit_xy()`. See
+#' `allow_sparse_x` column of [parsnip::get_encoding()] for sparse input 
+#' compatibility.
+#' 
 #' @examplesIf !parsnip:::is_cran_check()
 #' # Although `glm()` only has a formula interface, different
 #' # methods for specifying the model can be used

man/fit.Rd

@@ -50,4 +50,4 @@ sparse_hotel_rates <- function() {
 
   res <- as.matrix(res)
   Matrix::Matrix(res, sparse = TRUE)
-}
+}