## Usage

scale_alpha(..., range = c(0.1, 1))

scale_alpha_continuous(..., range = c(0.1, 1))

scale_alpha_discrete(..., range = c(0.1, 1))

## Arguments

- ...
- Other arguments passed on to
`continuous_scale`

or `discrete_scale`

as appropriate, to control name, limits,
breaks, labels and so forth.
- range
- range of output alpha values. Should lie between 0 and 1.

## Description

`scale_alpha`

is an alias for `scale_alpha_continuous`

since
that is the most common use of alpha, and it saves a bit of typing.

## Examples

(p <- ggplot(mtcars, aes(mpg, cyl)) +
geom_point(aes(alpha = cyl)))

p + scale_alpha("cylinders")

p + scale_alpha("number\nof\ncylinders")

p + scale_alpha(range = c(0.4, 0.8))

(p <- ggplot(mtcars, aes(mpg, cyl)) +
geom_point(aes(alpha = factor(cyl))))

p + scale_alpha_discrete(range = c(0.4, 0.8))