Single element panels still need to be resized (#2564)

* Single element panels still need to be resized

Fixes #2563

* Soften ggplot2.grouped_df

Fixes #2378

* Update authors in docs

Author: hadley

NEWS.md

@@ -364,8 +364,8 @@ up correct aspect ratio, and draws a graticule.
 * `fortify()` gains a method for tbls (@karawoo, #2218)
 
 * `ggplot` gains a method for `grouped_df`s that adds a `.group` variable,
-  which computes a unique value for each group, and automatically sets
-  the group aesthetic to use that variable (#2351).
+  which computes a unique value for each group. Use it with 
+  `aes(group = .group)` (#2351).
 
 * `ggproto()` produces objects with class `c("ggproto", "gg")`, allowing for
   a more informative error message when adding layers, scales, or other ggproto 

R/plot.r

@@ -116,8 +116,6 @@ ggplot.grouped_df <- function(data, mapping = aes(), ...,
                                environment = parent.frame()) {
 
   data$.group <- dplyr::group_indices(data)
-  mapping$group <- mapping$group %||% quote(.group)
-
   ggplot.data.frame(data, mapping = mapping, ..., environment = environment)
 }
 

R/position-dodge2.r

@@ -60,11 +60,6 @@ PositionDodge2 <- ggproto("PositionDodge2", PositionDodge,
 )
 
 pos_dodge2 <- function(df, width, n = NULL, padding = 0.1) {
-
-  if (length(unique(df$group)) == 1) {
-    return(df)
-  }
-
   if (!all(c("xmin", "xmax") %in% names(df))) {
     df$xmin <- df$x
     df$xmax <- df$x
@@ -128,9 +123,10 @@ pos_dodge2 <- function(df, width, n = NULL, padding = 0.1) {
 
 # Find groups of overlapping elements that need to be dodged from one another
 find_x_overlaps <- function(df) {
-  overlaps <- vector(mode = "numeric", length = nrow(df))
+  overlaps <- numeric(nrow(df))
   overlaps[1] <- counter <- 1
-  for (i in 2:nrow(df)) {
+
+  for (i in seq_asc(2, nrow(df))) {
     if (df$xmin[i] >= df$xmax[i - 1]) {
       counter <- counter + 1
     }

R/utilities.r

@@ -403,6 +403,14 @@ with_seed_null <- function(seed, code) {
   }
 }
 
+seq_asc <- function(to, from) {
+  if (to > from) {
+    integer()
+  } else {
+    to:from
+  }
+}
+
 # Needed to trigger package loading
 #' @importFrom tibble tibble
 NULL

tests/testthat/test-position-dodge2.R

@@ -16,6 +16,12 @@ test_that("find_x_overlaps identifies overlapping groups", {
   expect_equal(find_x_overlaps(df2), c(1, 1, 2, 2, 3))
 })
 
+test_that("single element is rescaled based on n", {
+  df <- data.frame(xmin = 1, xmax = 2)
+  out <- pos_dodge2(df, n = 2)
+  expect_equal(out$xmax - out$xmin, 0.5)
+})
+
 test_that("rectangles are dodged", {
   df <- data.frame(
     xmin = c(1, 3, 6, 11, 13),
@@ -38,7 +44,7 @@ test_that("cols at the same x position are dodged", {
     stringsAsFactors = FALSE
   )
 
-  p <- ggplot(df, aes(1, n, fill = x)) + 
+  p <- ggplot(df, aes(1, n, fill = x)) +
     geom_col(position = "dodge2", alpha = 0.5)
 
   expect_false(any(duplicated(find_x_overlaps(layer_data(p)))))
@@ -62,7 +68,7 @@ test_that("padding argument controls space between elements", {
   }
 
   expect_equal(gaps(d1), 0)
-  expect_equal(gaps(d2), 0.0375)  
+  expect_equal(gaps(d2), 0.0375)
 })
 
 test_that("boxes in facetted plots keep the correct width", {