geom_quadrant_lines: Reference lines: horizontal plus vertical, and quadrants

Description

geom_vhlines() adds in a single layer both vertical and horizontal guide lines. Can be thought of as a convenience function that helps with producing consistent vertical and horizontal guide lines. It behaves like geom_vline() and geom_hline(). geom_quadrant_lines() displays the boundaries of four quadrants with an arbitrary origin. The quadrants are specified in the same way as in stat_quadrant_counts() and is intended to be used to add guide lines consistent with the counts by quadrant computed by this stat.

Usage

geom_quadrant_lines(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  pool.along = c("none", "x", "y", "xy"),
  xintercept = 0,
  yintercept = 0,
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = FALSE,
  ...
)
geom_vhlines(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  xintercept = NULL,
  yintercept = NULL,
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = FALSE,
  ...
)

Value

A plot layer instance.

Arguments

mapping: The aesthetic mapping, usually constructed with aes. Only needs to be set at the layer level if you are overriding the plot defaults.
data: A layer specific data set - only needed if you want to override the plot defaults.
stat: The statistic object to use display the data
position: The position adjustment to use for overlapping points on this layer
pool.along: character, one of "none", "x", "y", or "xy" indicating whether to plot or not lines separating quadrants.
xintercept, yintercept: numeric vectors the coordinates of the origin of the quadrants.
na.rm: a logical indicating whether NA values should be stripped before the computation proceeds.
show.legend: logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes.
inherit.aes: If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and should not inherit behaviour from the default plot specification, e.g. borders.
...: other arguments passed on to layer. This can include aesthetics whose values you want to set, not map. See layer for more details.

Details

While geom_vhlines() does not provide defaults for the intercepts and accepts vectors of length > 1, geom_quadrant_lines() sets by default the intercepts to zero producing the natural quadrants and only accepts vectors of length one per panel. That is geom_vhlines() can be used to plot a grid while geom_quadrant_lines() plots at most one vertical and one horizontal line. In the case of geom_quadrant_lines() the pooling along axes can be specified in the same way as in stat_quadrant_counts().

Examples

Run this code

# generate artificial data
set.seed(4321)
x <- 1:100
y <- rnorm(length(x), mean = 10)
my.data <- data.frame(x, y)

ggplot(my.data, aes(x, y)) +
  geom_quadrant_lines() +
  geom_point()

ggplot(my.data, aes(x, y)) +
  geom_quadrant_lines(linetype = "dotted") +
  geom_point()

ggplot(my.data, aes(x, y)) +
  geom_quadrant_lines(xintercept = 50,
                      yintercept = 10,
                      colour = "blue") +
  geom_point()

ggplot(my.data, aes(x, y)) +
  geom_quadrant_lines(xintercept = 50,
                      pool.along = "y",
                      colour = "blue") +
  geom_point()

ggplot(my.data, aes(x, y)) +
  geom_vhlines(xintercept = c(25, 50, 75),
               yintercept = 10 ,
               linetype = "dotted",
               colour = "red") +
  geom_point() +
  theme_bw()

ggplot(my.data, aes(x, y)) +
  geom_vhlines(xintercept = c(25, 50, 75),
               yintercept = c(10, 8),
               linetype = "dotted",
               colour = "red") +
  geom_point() +
  theme_bw()