Scale for vector magnitudes

Allows to control the size of the arrows in geom_arrow. Highly experimental.

scale_mag(
  name = ggplot2::waiver(),
  n.breaks = 1,
  breaks = ggplot2::waiver(),
  oob = no_censor,
  ...
)

scale_mag_continuous(
  name = ggplot2::waiver(),
  n.breaks = 1,
  breaks = ggplot2::waiver(),
  oob = no_censor,
  ...
)

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.

n.breaks

An integer guiding the number of major breaks. The algorithm may choose a slightly different number to ensure nice break labels. Will only have an effect if breaks = waiver(). Use NULL to use the default number of breaks given by the transformation.

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()). Also accepts rlang lambda function notation.

oob

One of:

• Function that handles limits outside of the scale limits (out of bounds). Also accepts rlang lambda function notation.

• The default (scales::censor()) replaces out of bounds values with NA.

• scales::squish() for squishing out of bounds values into range.

• scales::squish_infinite() for squishing infinite values into range.

...

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

Examples

library(ggplot2)
g <- ggplot(seals, aes(long, lat)) +
    geom_vector(aes(dx = delta_long, dy = delta_lat), skip = 2)

g + scale_mag("Seals velocity")


g + scale_mag("Seals velocity", limits = c(0, 1))