Helpful scales for maps

These functions are simple wrappers around scale_x_continuous and scale_y_continuous with helpful defaults for plotting longitude, latitude and pressure levels.

scale_x_longitude(
  name = "",
  ticks = 30,
  breaks = seq(-180, 360, by = ticks),
  expand = c(0, 0),
  labels = LonLabel,
  trans = "identity",
  ...
)

scale_y_longitude(
  name = "",
  ticks = 60,
  breaks = seq(-180, 360, by = ticks),
  expand = c(0, 0),
  labels = LonLabel,
  trans = "identity",
  ...
)

scale_x_latitude(
  name = "",
  ticks = 30,
  breaks = seq(-90, 90, by = ticks),
  expand = c(0, 0),
  labels = LatLabel,
  ...
)

scale_y_latitude(
  name = "",
  ticks = 30,
  breaks = seq(-90, 90, by = ticks),
  expand = c(0, 0),
  labels = LatLabel,
  ...
)

scale_x_level(name = "", expand = c(0, 0), trans = "reverselog", ...)

scale_y_level(name = "", expand = c(0, 0), trans = "reverselog", ...)

Arguments

name

The name of the scale. Used as the axis or legend title. If waiver(), the default, the name of the scale is taken from the first mapping used for that aesthetic. If NULL, the legend title will be omitted.

ticks

spacing between breaks

breaks

One of:

• NULL for no breaks

• waiver() for the default breaks computed by the transformation object

• A numeric vector of positions

• A function that takes the limits as input and returns breaks as output (e.g., a function returned by scales::extended_breaks()). Note that for position scales, limits are provided after scale expansion. Also accepts rlang lambda function notation.

expand

For position scales, a vector of range expansion constants used to add some padding around the data to ensure that they are placed some distance away from the axes. Use the convenience function ggplot2::expansion() to generate the values for the expand argument.

labels

One of:

• NULL for no labels

• waiver() for the default labels computed by the transformation object

• A character vector giving labels (must be same length as breaks)

• An expression vector (must be the same length as breaks). See ?plotmath for details.

• A function that takes the breaks as input and returns labels as output. Also accepts rlang lambda function notation.

trans

Deprecated in favour of transform.

...

Other arguments passed on to scale_(x|y)_continuous()

See also

Other ggplot2 helpers: MakeBreaks(), WrapCircular(), geom_arrow(), geom_contour2(), geom_contour_fill(), geom_label_contour(), geom_relief(), geom_streamline(), guide_colourstrip(), map_labels, reverselog_trans(), scale_divergent, stat_na(), stat_subset()

Examples

data(geopotential)
library(ggplot2)
ggplot(geopotential[date == date[1]], aes(lon, lat, z = gh)) +
    geom_contour() +
    scale_x_longitude() +
    scale_y_latitude()


data(temperature)
ggplot(temperature[lon == lon[1] & lat == lat[1]], aes(air, lev)) +
    geom_path() +
    scale_y_level()