This guide is a version of the guide_legend()
guide for binned scales. It
differs in that it places ticks correctly between the keys, and sports a
small axis to better show the binning. Like guide_legend()
it can be used
for all non-position aesthetics though colour and fill defaults to
guide_coloursteps()
, and it will merge aesthetics together into the same
guide if they are mapped in the same way.
Usage
guide_bins(
title = waiver(),
title.position = NULL,
title.theme = NULL,
title.hjust = NULL,
title.vjust = NULL,
label = TRUE,
label.position = NULL,
label.theme = NULL,
label.hjust = NULL,
label.vjust = NULL,
keywidth = NULL,
keyheight = NULL,
axis = TRUE,
axis.colour = "black",
axis.linewidth = NULL,
axis.arrow = NULL,
ticks = NULL,
ticks.length = unit(0.2, "npc"),
direction = NULL,
default.unit = "line",
override.aes = list(),
reverse = FALSE,
order = 0,
show.limits = NULL,
...
)
Arguments
- title
A character string or expression indicating a title of guide. If
NULL
, the title is not shown. By default (waiver()
), the name of the scale object or the name specified inlabs()
is used for the title.- title.position
A character string indicating the position of a title. One of "top" (default for a vertical guide), "bottom", "left" (default for a horizontal guide), or "right."
- title.theme
A theme object for rendering the title text. Usually the object of
element_text()
is expected. By default, the theme is specified bylegend.title
intheme()
or theme.- title.hjust
A number specifying horizontal justification of the title text.
- title.vjust
A number specifying vertical justification of the title text.
- label
logical. If
TRUE
then the labels are drawn. IfFALSE
then the labels are invisible.- label.position
A character string indicating the position of a label. One of "top", "bottom" (default for horizontal guide), "left", or "right" (default for vertical guide).
- label.theme
A theme object for rendering the label text. Usually the object of
element_text()
is expected. By default, the theme is specified bylegend.text
intheme()
.- label.hjust
A numeric specifying horizontal justification of the label text. The default for standard text is 0 (left-aligned) and 1 (right-aligned) for expressions.
- label.vjust
A numeric specifying vertical justification of the label text.
- keywidth
A numeric or a
grid::unit()
object specifying the width of the legend key. Default value islegend.key.width
orlegend.key.size
intheme()
.- keyheight
A numeric or a
grid::unit()
object specifying the height of the legend key. Default value islegend.key.height
orlegend.key.size
intheme()
.- axis
A theme object for rendering a small axis along the guide. Usually, the object of
element_line()
is expected (default). Ifelement_blank()
, no axis is drawn. For backward compatibility, can also be a logical which translatesTRUE
toelement_line()
andFALSE
toelement_blank()
.- axis.colour, axis.linewidth
Graphic specifications for the look of the axis.
- axis.arrow
A call to
arrow()
to specify arrows at the end of the axis line, thus showing an open interval.- ticks
A theme object for rendering tick marks at the colourbar. Usually, the object of
element_line()
is expected. Ifelement_blank()
, no tick marks are drawn. IfNULL
(default), theaxis
argument is re-used asticks
argument (without arrow).- ticks.length
A numeric or a
grid::unit()
object specifying the length of tick marks between the keys.- direction
A character string indicating the direction of the guide. One of "horizontal" or "vertical."
- default.unit
A character string indicating
grid::unit()
forkeywidth
andkeyheight
.- override.aes
A list specifying aesthetic parameters of legend key. See details and examples.
- reverse
logical. If
TRUE
the order of legends is reversed.- order
positive integer less than 99 that specifies the order of this guide among multiple guides. This controls the order in which multiple guides are displayed, not the contents of the guide itself. If 0 (default), the order is determined by a secret algorithm.
- show.limits
Logical. Should the limits of the scale be shown with labels and ticks. Default is
NULL
meaning it will take the value from the scale. This argument is ignored iflabels
is given as a vector of values. If one or both of the limits is also given inbreaks
it will be shown irrespective of the value ofshow.limits
.- ...
ignored.
Use with discrete scale
This guide is intended to show binned data and work together with ggplot2's
binning scales. However, it is sometimes desirable to perform the binning in
a separate step, either as part of a stat (e.g. stat_contour_filled()
) or
prior to the visualisation. If you want to use this guide for discrete data
the levels must follow the naming scheme implemented by base::cut()
. This
means that a bin must be encoded as "(<lower>, <upper>]"
with <lower>
giving the lower bound of the bin and <upper>
giving the upper bound
("[<lower>, <upper>)"
is also accepted). If you use base::cut()
to
perform the binning everything should work as expected, if not, some recoding
may be needed.
See also
Other guides:
guide_colourbar()
,
guide_coloursteps()
,
guide_legend()
,
guides()
Examples
p <- ggplot(mtcars) +
geom_point(aes(disp, mpg, size = hp)) +
scale_size_binned()
# Standard look
p
# Remove the axis or style it
p + guides(size = guide_bins(axis = FALSE))
p + guides(size = guide_bins(show.limits = TRUE))
p + guides(size = guide_bins(
axis.arrow = arrow(length = unit(1.5, 'mm'), ends = 'both')
))
# Guides are merged together if possible
ggplot(mtcars) +
geom_point(aes(disp, mpg, size = hp, colour = hp)) +
scale_size_binned() +
scale_colour_binned(guide = "bins")