documentation fix

R/pca.R

@@ -64,9 +64,9 @@
 #'   # old base R plotting method:
 #'   biplot(pca_result)
 #'   # new ggplot2 plotting method using this package:
-#'   ggplot_pca(pca_result)
-#'
 #'   if (require("ggplot2")) {
+#'     ggplot_pca(pca_result)
+#'
 #'     ggplot_pca(pca_result) +
 #'       scale_colour_viridis_d() +
 #'       labs(title = "Title here")