CTTKhexagon: Chittka (1992) colour hexagon

Description

Plots Chittka (1992) colour hexagon for trichromatic animals and a line plot for dichromatic animals.

Usage

CTTKhexagon(x, y, photo=3,
            vnames=c(expression(E[1]),expression(E[2]),expression(E[3])),
            pch=16, bty="n", yaxt="n",xaxt="n", col="black",
            xlim="auto", ylim="auto", asp=1, ann=FALSE,
            axes=FALSE, vectors=FALSE, ...)

Arguments

x: x-coordinate
y: y-coordinate. y=0 when photo=2
photo: Number of photoreceptor types. photo=3 for a trichromatic animal, and photo=2 for a dichromatic animal.
vnames: Vector names.
pch: see par function.
bty: see par function.
yaxt: see par function.
xaxt: see par function.
col: see par function.
xlim: see plot function. Default calculates xlim automatically.
ylim: see plot function. Default calculates ylim automatically.
asp: see plot function.
ann: see par function.
axes: see plot.default function.
vectors: Whether vectors representing direction of photoreceptor outputs should be plotted.
...: Other arguments passed to plot function.

Author

Felipe M. Gawryszewski f.gawry@gmail.com

References

Chittka, L. 1992. The colour hexagon: a chromaticity diagram based on photoreceptor excitations as a generalized representation of colour opponency. J Comp Physiol A 170:533-543.

Examples

Run this code

##Honeybee photoreceptor sensitivity curves
data("bee")

##Grey background:
## with 7 percent reflectance from 300 to 700nm:
Rb <- data.frame(300:700, rep(7, length(300:700)))

## Read CIE D65 standard illuminant already converted to quantum flux:
data("D65")

##Reflectance data
## with a sigmoid spectrum and midpoint at 500nm and 550 nm
R1<-logistic(x=seq(300,700,1), x0=500, L=50, k=0.04)
R2<-logistic(x=seq(300,700,1), x0=550, L=50, k=0.04)
R<-cbind(R1, R2[,2])

## Run colour vision model:
model<-CTTKmodel(photo="tri", R=R, I=D65, Rb=Rb,
C=bee)

##plot data in the colour space
CTTKhexagon(x=model[,"X1"], y=model[,"X2"])