Apply partial colour ramps

Given vectors of colours and partial_colour_ramps, ramps the colours according to the parameters of the partial colour ramps, returning a vector of the same length as the inputs giving the transformed (ramped) colours.

Usage

ramp_colours(colour, ramp)

Arguments

colour

character vector of colours.

ramp

a partial_colour_ramp vector.

Value

A character vector of colours.

Details

Takes vectors of colours and partial_colour_ramps and produces colours by interpolating between each from colour and the target colour the specified amount (where amount and from are the corresponding fields of the ramp).

For example, to add support for the fill_ramp aesthetic to a geometry, this line could be used inside the draw_group() or draw_panel() method of a geom:

data$fill = ramp_colours(data$fill, data$fill_ramp)

See also

Other colour ramp functions: guide_rampbar(), partial_colour_ramp(), scale_colour_ramp

Author

Matthew Kay

Examples

pcr = partial_colour_ramp(c(0, 0.25, 0.75, 1), "red")
pcr
#> <partial_colour_ramp[4]>
#> [1] [0 from red]    [0.25 from red] [0.75 from red] [1 from red]   

ramp_colours("blue", pcr)
#> [1] "#FF0000" "#E80050" "#9A00C3" "#0000FF"