scale_size {ggplot2} | R Documentation

## Scale size (area or radius).

### Description

`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. Built-in 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 with `trans_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

    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()

[Package ggplot2 version 2.1.0 Index]