scale_size
Scales for area or radius
scale_size
scales area, scale_radius
scales radius. The size
aesthetic is most commonly used for points and text, and humans perceive
the area of points (not their radius), so this provides for optimal
perception. scale_size_area
ensures that a value of 0 is mapped
to a size of 0.
Usage
scale_radius(name = waiver(), breaks = waiver(), labels = waiver(), limits = NULL, range = c(1, 6), trans = "identity", guide = "legend")
scale_size(name = waiver(), breaks = waiver(), labels = waiver(), limits = NULL, range = c(1, 6), trans = "identity", guide = "legend")
scale_size_area(..., max_size = 6)
Arguments
 name
 The name of the scale. Used as axis or legend title. If
NULL
, the default, the name of the scale is taken from the first mapping used for that aesthetic.  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

 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
)  A function that takes the breaks as input and returns labels as output

 limits
 A numeric vector of length two providing limits of the scale.
Use
NA
to refer to the existing minimum or maximum.  range
 a numeric vector of length 2 that specifies the minimum and maximum size of the plotting symbol after transformation.
 trans
 Either the name of a transformation object, or the
object itself. Builtin transformations include "asn", "atanh",
"boxcox", "exp", "identity", "log", "log10", "log1p", "log2",
"logit", "probability", "probit", "reciprocal", "reverse" and "sqrt".
A transformation object bundles together a transform, it's inverse, and methods for generating breaks and labels. Transformation objects are defined in the scales package, and are called
name_trans
, e.g.boxcox_trans
. You can create your own transformation withtrans_new
.  guide
 Name of guide object, or object itself.
 ...
 Other arguments passed on to
continuous_scale
to control name, limits, breaks, labels and so forth.  max_size
 Size of largest points.
See Also
scale_size_area
if you want 0 values to be mapped
to points with size 0.
Examples
library(ggplot2)
p < ggplot(mpg, aes(displ, hwy, size = hwy)) +
geom_point()
p
p + scale_size("Highway mpg")
p + scale_size(range = c(0, 10))
# If you want zero value to have zero size, use scale_size_area:
p + scale_size_area()
# This is most useful when size is a count
ggplot(mpg, aes(class, cyl)) +
geom_count() +
scale_size_area()
# If you want to map size to radius (usually bad idea), use scale_radius
p + scale_radius()