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.
scale_alpha(..., range = c(0.1, 1)) scale_alpha_continuous(..., range = c(0.1, 1)) scale_alpha_discrete(...) scale_alpha_ordinal(..., range = c(0.1, 1))
... | Other arguments passed on to |
---|---|
range | Output range of alpha values. Must lie between 0 and 1. |
Other colour scales: scale_colour_brewer
,
scale_colour_gradient
,
scale_colour_grey
,
scale_colour_hue
,
scale_colour_viridis_d
p + scale_alpha("cylinders")p + scale_alpha(range = c(0.4, 0.8))