position_dodge: Dodge overlapping objects side-to-side

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

Description

Dodging preserves the vertical position of an geom while adjusting the horizontal position.

Usage

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

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?

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 = "dodge")

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


ggplot(diamonds, aes(price, fill = cut)) +
  geom_histogram(position="dodge")
# see ?geom_boxplot and ?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)
)

duthedd/ggplot2 documentation built on May 20, 2019, 11:13 a.m.