return value and examples for theme_pcp

CRAN-SUBMISSION

@@ -0,0 +1,3 @@
+Version: 0.2.0
+Date: 2022-11-25 16:11:42 UTC
+SHA: 9a1786a98508575c3747f01c6abf4a44b6e66ad5

R/theme_pcp.R

@@ -1,16 +1,29 @@
 #' Theme for parallel coordinate plots
 #'
 #' The function `theme_pcp` provides a wrapper for thematic
-#' choices suitable for parallel coordinate axes. In particular,
-#' axes labeling in parallel coordinate plot is quite un-informative,
-#' as they are based by default on variable names derived during the
+#' choices suitable for parallel coordinate plots. In particular,
+#' the labeling of axes in parallel coordinate plot is quite un-informative.
+#' In the default theme axes labels are based on variable names derived during the
 #' data wrangling step.
-#'
 #' @inheritParams ggplot2::theme_bw
 #' @export
 #' @importFrom ggplot2 %+replace%
+#' @return A `ggplot2` theme object based on [ggplot2::theme_bw()] without y axis and x axes labels.
+#' @seealso [ggplot2::theme_bw()]
+#' @examples
+#' library(ggplot2)
+#' gg <- iris |>
+#'   pcp_select(tidyselect::everything()) |>
+#'   pcp_scale() |>
+#'   pcp_arrange() |>
+#'   ggplot(aes_pcp(colour = Species)) +
+#'     geom_pcp()
 #'
-theme_pcp <- function(base_size = 9, base_family = "") {
+#' # plot with the default ggplot2 theme
+#' gg
+#' # better:
+#' gg + theme_pcp()
+theme_pcp <- function(base_size = 11, base_family = "") {
   theme_bw(base_size = base_size, base_family = base_family) %+replace%
     theme(axis.text.y = element_blank(),
           axis.ticks.y = element_blank(),