On Fri, Mar 18, 2011 at 3:37 PM, Frank Schwach <f...@sanger.ac.uk> wrote: > Hi, > > I'm plotting a heatmap with values ranging from -10 to +10 and I would > like the negative values to show up in shades of blue and the positive > ones in shadea of red. Basically, I want exactly what the RColorBrewer > palette RdBu does but with more of a gradual change (the RdBu can only > give me 11 distinct colours). Any suggestions?
Use RColorBrewer along with my colourscheme package [https://r-forge.r-project.org/R/?group_id=435] to interpolate between them: library(RColorBrewer) bp = brewer.pal(11,"RdBu") library(colourschemes) cs = rampInterpolate(c(-10,10),bp) now cs is a function that interpolates the 11 palette colours so you have a continuous colour palette. Note the interpolation is (umm I think) linear in R G and B. s=seq(-10,10,len=100 plot(s,s,col=cs(s),pch=19) gives you 100 different colours. Barry ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
