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.
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:
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
The linetype to use for NA
values.
The documentation for differentiation related aesthetics.
Other linetype scales: scale_linetype_manual()
, scale_linetype_identity()
.
The line type section of the online ggplot2 book.
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)