Color Ramps on Perceptually Linear Scales
Functions for returning colors on perceptually linear scales, where steps correspond to ‘just detectable differences’.
LinGray (n, beg=1, end=92) BTC (n, beg=1, end=256) LinOCS (n, beg=1, end=256) heat.ob (n, beg=1, end=256) magent (n, beg=1, end=256) plinrain(n, beg=1, end=256)
n |
number of colors to return from the ramp |
beg |
begining of ramp, integer from 1-255 |
end |
end of ramp, integer from 1-255 |
Several precalulated color ramps, that are on a perceptually linear color scale. A perceptually linear color scale is a scale where each jump corresponds to a “just detectable difference” in color and the scale is percieved as linear by the human eye (emprically determined).
When using the ramps, if beg is less than end the ramp
will be reversed.
returns an array of colors
Nicholas Lewin-Koh
Haim Levkowitz (1997) Color Theory and Modeling for Computer Graphics, Visualization, and Multimedia Applications. Kluwer Academic Publishers, Boston/London/Dordrecht. http://www.cs.uml.edu/~haim/ColorCenter/
h <- hexbin(rnorm(10000),rnorm(10000))
plot(h, colramp= BTY)
## looks better if you shave the tails:
plot(h, colramp= function(n){LinOCS(n,beg=15,end=225)})Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.