check for availability of Hmisc. closes #3857 (#3858)

Author: clauswilke

R/stat-summary.r

@@ -226,11 +226,13 @@ summarise_by_x <- function(data, summary, ...) {
 #' @return A data frame with columns `y`, `ymin`, and `ymax`.
 #' @name hmisc
 #' @examples
+#' if (requireNamespace("Hmisc", quietly = TRUE)) {
 #' x <- rnorm(100)
 #' mean_cl_boot(x)
 #' mean_cl_normal(x)
 #' mean_sdl(x)
 #' median_hilow(x)
+#' }
 NULL
 
 wrap_hmisc <- function(fun) {