R: Color Ramps on Perceptually Linear Scales

ColorRamps {hexbin} | R Documentation

## Color Ramps on Perceptually Linear Scales

### Description

Functions for returning colors on perceptually linear scales, where steps correspond to ‘just detectable differences’.

### Usage

    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)

### Arguments

`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

### Details

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.

### Value

returns an array of colors

### Author(s)

Nicholas Lewin-Koh

### References

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/

### See Also

`rainbow`, `terrain.colors`, `rgb`, `hsv`

### Examples

    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)})

[Package hexbin version 1.27.3 Index]