added tinyplot.data.frame method

NAMESPACE

@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+S3method(tinyplot,data.frame)
 S3method(tinyplot,default)
 S3method(tinyplot,density)
 S3method(tinyplot,formula)

R/tinyplot.data.frame.R

@@ -0,0 +1,58 @@
+#' tinyplot Method for Plotting Data Frames
+#'
+#' @description Convenience interface for visualizing data.frame objects
+#'   with tinyplot.
+#'
+#' @details This is a convenience function for plotting data frames with
+#'   or without a formula. The case with the formula mainly facilitates
+#'   using `tinyplot()` in combination with pipes. The case without
+#'   formula provides a quick way of plotting the variables in data frames,
+#'   either only one variable or a pair of variables. In the future, the
+#'   latter might be extended to a pairs display for data frames with
+#'   more than two variables but this is not implemented, yet. See the
+#'   examples for illustrations.
+#'
+#' @param x an object of class `"data.frame"`.
+#' @param formula a \code{\link[stats]{formula}} that is passed on to
+#'   \code{\link{tinyplot.formula}}. If `formula` is `NULL` a formula of
+#'   type `y ~ 1` or `y ~ x` is set up for 1- and 2-dimensional data frames,
+#'   respectively. For data frames with more than 2 variables the `facet = NULL`
+#'   case is not supported, yet, and currently leads to an error.
+#' @param ... further arguments passed to `tinyplot`. 
+#'
+#' @examples
+#' tinytheme("clean2")
+#' 
+#' ## using tinyplot() with data frames and pipes
+#' cars |> tinyplot()
+#' iris |> tinyplot(Sepal.Length ~ Petal.Width | Species)
+#'
+#' ## tinyplot(df) only works for data frames with 1 or 2 variables
+#' ## in the future we might add a pairs-style display as follows
+#' ## but this would require better handling of axes and their labels
+#' par(mfrow = c(5, 5))
+#' for (i in names(iris)) for(j in names(iris)) tinyplot(iris[, unique(c(j, i)), drop = FALSE])
+#'
+#' tinytheme() ## reset
+#'
+#' @export
+tinyplot.data.frame = function (x, formula = NULL, ...) {
+  ## original call
+  cl = match.call()
+
+  ## default formula
+  ## 1d: y ~ 1
+  ## 2d: y ~ x
+  ## 3d: pairs? (not supported, yet)
+  if (is.null(formula)) {
+    if (ncol(x) > 2L) stop("'formula' is missing with no default for more than 2 columns")
+    f = names(x)
+    if (length(f) < 2L) f = c("1", f)
+    cl$formula = as.formula(paste(f[2L:1L], collapse = " ~ "))
+  }
+
+  ## evaluate updated call
+  names(cl)[names(cl) == "x"] = "data"
+  cl[[1L]] = quote(tinyplot::tinyplot)
+  eval.parent(cl)
+}