An R function to generate color bar legends for neuroimaging plots

colorbar.R

# Source: http://stackoverflow.com/a/9314880
color.bar <- function(lut, min, max=-min, nticks=11, ticks=seq(min, max, len=nticks), title='') {
  scale = (length(lut))/(max-min)
  # dev.new(width=1.75, height=5)
  plot(c(0,10), c(min,max), type='n', bty='n', xaxt='n', xlab='', yaxt='n', ylab='', main=title)
  axis(2, round(ticks, 2), las=1)
  for (i in 1:(length(lut))) {
    y = (i-1)/scale + min
    rect(0,y,10,y+1/scale, col=lut[i], border=NA)
  }
}