ggplot2: scale_alpha – R documentation

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scale_alpha

Alpha transparency scales

Description

Alpha-transparency scales are not tremendously useful, but can be a convenient way to visually down-weight less important observations. 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.

Usage

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

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

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

scale_alpha_discrete(...)

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

Arguments

`...`	Other arguments passed on to `continuous_scale()`, binned_scale, or `discrete_scale()` as appropriate, to control name, limits, breaks, labels and so forth.
`range`	Output range of alpha values. Must lie between 0 and 1.

Examples

p <- ggplot(mpg, aes(displ, hwy)) +
  geom_point(aes(alpha = year))

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

ggplot2

Create Elegant Data Visualisations Using the Grammar of Graphics

v3.3.3

MIT + file LICENSE

Authors

Hadley Wickham [aut] (<https://orcid.org/0000-0003-4757-117X>), Winston Chang [aut] (<https://orcid.org/0000-0002-1576-2126>), Lionel Henry [aut], Thomas Lin Pedersen [aut, cre] (<https://orcid.org/0000-0002-5147-4711>), Kohske Takahashi [aut], Claus Wilke [aut] (<https://orcid.org/0000-0002-7470-9261>), Kara Woo [aut] (<https://orcid.org/0000-0002-5125-4188>), Hiroaki Yutani [aut] (<https://orcid.org/0000-0002-3385-7233>), Dewey Dunnington [aut] (<https://orcid.org/0000-0002-9415-4582>), RStudio [cph, fnd]

Initial release