CTTKhexagon {colourvision}

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(s)

Felipe M. Gawryszewski [e-mail]

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.

See Also

CTTKmodel, CTTKhexagon3D

Examples

##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"])