position_dodge: Dodge overlapping objects side-to-side

In TomeTiger/ggplot2: Create Elegant Data Visualisations Using the Grammar of Graphics

Description

Dodging preserves the vertical position of an geom while adjusting the horizontal position. position_dodge2 is a special case of position_dodge for arranging box plots, which can have variable widths. position_dodge2 also works with bars and rectangles.

Usage

position_dodge(width = NULL, preserve = c("total", "single"))

position_dodge2(width = NULL, preserve = c("total", "single"),
  padding = 0.1, reverse = FALSE)

Arguments

width	Dodging width, when different to the width of the individual elements. This is useful when you want to align narrow geoms with wider geoms. See the examples.
preserve	Should dodging preserve the total width of all elements at a position, or the width of a single element?
padding	Padding between elements at the same position. Elements are shrunk by this proportion to allow space between them. Defaults to 0.1.
reverse	If TRUE, will reverse the default stacking order. This is useful if you're rotating both the plot and legend.

See Also

Other position adjustments: position_identity, position_jitterdodge, position_jitter, position_nudge, position_stack

Examples

ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = "dodge2")

# By default, dodging with `position_dodge2()` preserves the width of each
# element. You can choose to preserve the total width with:
ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = position_dodge(preserve = "total"))


ggplot(diamonds, aes(price, fill = cut)) +
  geom_histogram(position="dodge2")
# see ?geom_bar for more examples

# In this case a frequency polygon is probably a better choice
ggplot(diamonds, aes(price, colour = cut)) +
  geom_freqpoly()


# Dodging with various widths -------------------------------------
# To dodge items with different widths, you need to be explicit
df <- data.frame(x = c("a","a","b","b"), y = 2:5, g = rep(1:2, 2))
p <- ggplot(df, aes(x, y, group = g)) +
  geom_col(position = "dodge", fill = "grey50", colour = "black")
p

# A line range has no width:
p + geom_linerange(aes(ymin = y - 1, ymax = y + 1), position = "dodge")

# So you must explicitly specify the width
p + geom_linerange(
  aes(ymin = y - 1, ymax = y + 1),
  position = position_dodge(width = 0.9)
)

# The same principle applies to error bars, which are usually
# narrower than the bars
p + geom_errorbar(
  aes(ymin = y - 1, ymax = y + 1),
  width = 0.2,
  position = "dodge"
)
p + geom_errorbar(
  aes(ymin = y - 1, ymax = y + 1),
  width = 0.2,
  position = position_dodge(width = 0.9)
)

# Box plots use position_dodge2 by default, and bars can use it too
ggplot(data = iris, aes(Species, Sepal.Length)) +
  geom_boxplot(aes(colour = Sepal.Width < 3.2))

ggplot(data = iris, aes(Species, Sepal.Length)) +
  geom_boxplot(aes(colour = Sepal.Width < 3.2), varwidth = TRUE)

ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = position_dodge2(preserve = "single"))

ggplot(mtcars, aes(factor(cyl), fill = factor(vs))) +
  geom_bar(position = position_dodge2(preserve = "total"))

TomeTiger/ggplot2 documentation built on May 29, 2019, 7:53 a.m.