annotation_logticks: Annotation: log tick marks
In ggplot2: Create Elegant Data Visualisations Using the Grammar of Graphics

annotation_logticks

R Documentation

Annotation: log tick marks

Description

This function is superseded by using guide_axis_logticks().

This annotation adds log tick marks with diminishing spacing. These tick marks probably make sense only for base 10.

Usage

annotation_logticks(
  base = 10,
  sides = "bl",
  outside = FALSE,
  scaled = TRUE,
  short = unit(0.1, "cm"),
  mid = unit(0.2, "cm"),
  long = unit(0.3, "cm"),
  colour = "black",
  linewidth = 0.5,
  linetype = 1,
  alpha = 1,
  color = NULL,
  ...,
  size = deprecated()
)

Arguments

`base`	the base of the log (default 10)
`sides`	a string that controls which sides of the plot the log ticks appear on. It can be set to a string containing any of `"trbl"`, for top, right, bottom, and left.
`outside`	logical that controls whether to move the log ticks outside of the plot area. Default is off (`FALSE`). You will also need to use `coord_cartesian(clip = "off")`. See examples.
`scaled`	is the data already log-scaled? This should be `TRUE` (default) when the data is already transformed with `log10()` or when using `scale_y_log10()`. It should be `FALSE` when using `coord_trans(y = "log10")`.
`short`	a `grid::unit()` object specifying the length of the short tick marks
`mid`	a `grid::unit()` object specifying the length of the middle tick marks. In base 10, these are the "5" ticks.
`long`	a `grid::unit()` object specifying the length of the long tick marks. In base 10, these are the "1" (or "10") ticks.
`colour`	Colour of the tick marks.
`linewidth`	Thickness of tick marks, in mm.
`linetype`	Linetype of tick marks (`solid`, `dashed`, etc.)
`alpha`	The transparency of the tick marks.
`color`	An alias for `colour`.
`...`	Other parameters passed on to the layer
`size`

Examples

# Make a log-log plot (without log ticks)
a <- ggplot(msleep, aes(bodywt, brainwt)) +
 geom_point(na.rm = TRUE) +
 scale_x_log10(
   breaks = scales::trans_breaks("log10", function(x) 10^x),
   labels = scales::trans_format("log10", scales::math_format(10^.x))
 ) +
 scale_y_log10(
   breaks = scales::trans_breaks("log10", function(x) 10^x),
   labels = scales::trans_format("log10", scales::math_format(10^.x))
 ) +
 theme_bw()

a + annotation_logticks()                # Default: log ticks on bottom and left
a + annotation_logticks(sides = "lr")    # Log ticks for y, on left and right
a + annotation_logticks(sides = "trbl")  # All four sides

a + annotation_logticks(sides = "lr", outside = TRUE) +
 coord_cartesian(clip = "off")  # Ticks outside plot

# Hide the minor grid lines because they don't align with the ticks
a + annotation_logticks(sides = "trbl") + theme(panel.grid.minor = element_blank())

# Another way to get the same results as 'a' above: log-transform the data before
# plotting it. Also hide the minor grid lines.
b <- ggplot(msleep, aes(log10(bodywt), log10(brainwt))) +
 geom_point(na.rm = TRUE) +
 scale_x_continuous(name = "body", labels = scales::label_math(10^.x)) +
 scale_y_continuous(name = "brain", labels = scales::label_math(10^.x)) +
 theme_bw() + theme(panel.grid.minor = element_blank())

b + annotation_logticks()

# Using a coordinate transform requires scaled = FALSE
t <- ggplot(msleep, aes(bodywt, brainwt)) +
  geom_point() +
  coord_trans(x = "log10", y = "log10") +
  theme_bw()
t + annotation_logticks(scaled = FALSE)

# Change the length of the ticks
a + annotation_logticks(
  short = unit(.5,"mm"),
  mid = unit(3,"mm"),
  long = unit(4,"mm")
)

ggplot2 documentation built on June 22, 2024, 11:35 a.m.