Improve documentation for geom_histogram(). (#3424, fixes #3269)

* Improving documentation for geom_histogram().

Author: accustodio

R/geom-histogram.r

@@ -12,8 +12,10 @@
 #'
 #' By default, the underlying computation (`stat_bin()`) uses 30 bins;
 #' this is not a good default, but the idea is to get you experimenting with
-#' different bin widths. You may need to look at a few to uncover the full
-#' story behind your data.
+#' different number of bins. You can also experiment modifying the `binwidth` with
+#' `center` or `boundary` arguments. `binwidth` overrides `bins` so you should do
+#' one change at a time. You may need to look at a few options to uncover
+#' the full story behind your data.
 #'
 #' @section Aesthetics:
 #' `geom_histogram()` uses the same aesthetics as [geom_bar()];

R/stat-bin.r

@@ -1,10 +1,10 @@
 #' @param binwidth The width of the bins. Can be specified as a numeric value
-#'   or as a function that calculates width from unscaled x. Here, "unscaled x" 
-#'   refers to the original x values in the data, before application of any 
+#'   or as a function that calculates width from unscaled x. Here, "unscaled x"
+#'   refers to the original x values in the data, before application of any
 #'   scale transformation. When specifying a function along with a grouping
-#'   structure, the function will be called once per group. 
-#'   The default is to use `bins`
-#'   bins that cover the range of the data. You should always override
+#'   structure, the function will be called once per group.
+#'   The default is to use the number of bins in `bins`,
+#'   covering the range of the data. You should always override
 #'   this value, exploring multiple widths to find the best to illustrate the
 #'   stories in your data.
 #'