Scale for line patterns

Default line types based on a set supplied by Richard Pearson, University of Manchester. Continuous values can not be mapped to line types unless scale_linetype_binned() is used. Still, as linetypes has no inherent order, this use is not advised.

Usage

scale_linetype(name = waiver(), ..., na.value = "blank")

scale_linetype_binned(name = waiver(), ..., na.value = "blank")

scale_linetype_continuous(...)

scale_linetype_discrete(name = waiver(), ..., na.value = "blank")

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.

...

Arguments passed on to discrete_scale

palette

A palette function that when called with a single integer argument (the number of levels in the scale) returns the values that they should take (e.g., scales::pal_hue()).

breaks

One of:

• NULL for no breaks

• waiver() for the default breaks (the scale limits)

• A character vector of breaks

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

limits

One of:

• NULL to use the default scale values

• A character vector that defines possible values of the scale and their order

• A function that accepts the existing (automatic) values and returns new ones. Also accepts rlang lambda function notation.

drop

Should unused factor levels be omitted from the scale? The default, TRUE, uses the levels that appear in the data; FALSE includes the levels in the factor. Please note that to display every level in a legend, the layer should use show.legend = TRUE.

na.translate

Unlike continuous scales, discrete scales can easily show missing values, and do so by default. If you want to remove missing values from a discrete scale, specify na.translate = FALSE.

aesthetics

The names of the aesthetics that this scale works with.

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.

guide

A function used to create a guide or its name. See guides() for more information.

call

The call used to construct the scale for reporting messages.

super

The super class to use for the constructed scale

na.value

The linetype to use for NA values.

See also

The documentation for differentiation related aesthetics.

Other linetype scales: scale_linetype_manual(), scale_linetype_identity().

The line type section of the online ggplot2 book.

Examples

base <- ggplot(economics_long, aes(date, value01))
base + geom_line(aes(group = variable))

base + geom_line(aes(linetype = variable))


# See scale_manual for more flexibility

# Common line types ----------------------------
df_lines <- data.frame(
  linetype = factor(
    1:4,
    labels = c("solid", "longdash", "dashed", "dotted")
  )
)
ggplot(df_lines) +
  geom_hline(aes(linetype = linetype, yintercept = 0), linewidth = 2) +
  scale_linetype_identity() +
  facet_grid(linetype ~ .) +
  theme_void(20)