rggplot2colorbrewer

Can I adjust the lower limit of scale_color_brewer?


I have ordered categorical data that I would like to use color brewer on. But I have a hard time seeing the very light lower values. Is there a way to either trim off those lower values or set the lower limit in the scale?

ggplot(data.frame(x=1:6, y=10:15, w=letters[1:6]), aes(x, y, color=w)) + 
geom_point()+ scale_color_brewer(type="seq", palette=1) + theme_bw()

Is there a better way to do this? So far I either see qualitative scales that aren't ordered or continuous scales that don't like being applied to discrete data. I'm aware of manual scales if that's the only route.


Solution

  • You cannot just set a lower limit. But you can use a palette with more colors than needed and map the brightest colors to unused levels. Below is an example with 9 levels:

    ggplot(data.frame(x=1:6, y=10:15, w=letters[1:6]), aes(x, y, color=w)) + 
      geom_point() + theme_bw() + 
      scale_color_brewer(type="seq", palette=1, 
                         limits=c(LETTERS[1:3], letters[1:6]), 
                         breaks=letters[1:6])