Allow to reverse the order of colours in a brewer palette

[jiho]

Use the same argument that scale_*_hue uses: direction

[jiho]

Requires a change in scales, in pull request 36 r-lib/scales#36

[jiho]

Even if color brewer scales are meant to be discrete, sometimes they can be used to denote ordered factors (such as abundance classes, etc.). In that case, many brewer palettes go in the "wrong" direction, associating warm colours with small values. For example:

library(ggplot2)
set.seed(123)
d <- data.frame(x=runif(100), y=runif(100), z=factor(round(runif(10)*5)))
p <- ggplot(d) + geom_point(aes(x, y, colour=z))
p + scale_color_brewer(palette="Spectral")

Now compare with

p + scale_color_brewer(palette="Spectral", direction=-1)

[hadley]

Could you please rebase/merge against master, re-document with the development version of roxygen2 (install_github("klutometis/roxygen) and resubmit?

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/