add has_sparse_elements

NAMESPACE

@@ -7,6 +7,7 @@ export(as_sparse_logical)
 export(coerce_to_sparse_data_frame)
 export(coerce_to_sparse_matrix)
 export(coerce_to_sparse_tibble)
+export(has_sparse_elements)
 export(is_sparse_character)
 export(is_sparse_double)
 export(is_sparse_integer)

R/has_sparse_elements.R

@@ -0,0 +1,40 @@
+#' Check for sparse elements
+#' 
+#' This function checks to see if a data.frame, tibble or list contains one or
+#' more sparse vectors.
+#' 
+#' @param x a data frame, tibble, or list.
+#'
+#' @details
+#' The checking in this function is done using [is_sparse_vector()], but is 
+#' implemented using an early exit pattern to provide fast performance for wide
+#' data.frames.
+#' 
+#' This function does not test whether `x` is a data.frame, tibble or list. It
+#' simply iterates over the elements and sees if they are sparse vectors.
+#' 
+#' @return A single logical value.
+#' 
+#' @examplesIf rlang::is_installed("Matrix")
+#' set.seed(1234)
+#' n_cols <- 10000
+#' mat <- matrix(sample(0:1, n_cols * 10, TRUE, c(0.9, 0.1)), ncol = n_cols)
+#' colnames(mat) <- as.character(seq_len(n_cols))
+#' sparse_mat <- Matrix::Matrix(mat, sparse = TRUE)
+#' 
+#' res <- coerce_to_sparse_tibble(sparse_mat)
+#' has_sparse_elements(res)
+#' 
+#' has_sparse_elements(mtcars)
+#' @export
+has_sparse_elements <- function(x) {
+  res <- FALSE
+
+  for (elt in x) {
+    if (is_sparse_vector(elt)) {
+      res <- TRUE
+      break
+    }
+  }
+  res
+}

_pkgdown.yml

@@ -30,3 +30,4 @@ reference:
     contents:
     - type-predicates
     - extractors
+    - has_sparse_elements