Colour hexagon

Calculates coordinates and colourimetric variables that represent reflectance spectra in the hymenopteran colour hexagon.

hexagon(vismodeldata)

Arguments

vismodeldata

(required) quantum catch colour data. Can be either the result from vismodel() or independently calculated data (in the form of a data frame with three columns named 's', 'm', 'l', representing a trichromatic viewer).

Value

A data frame of class colspace consisting of the following columns:

• s, m, l: the quantum catch data used to calculate the remaining variables

• x, y: cartesian coordinates in the colour hexagon.

• h.theta: hue angle theta (in degrees), with 0-degrees at the 1200 angle, increasing clockwise.

• r.vec: the r vector (saturation, distance from the center).

• sec.fine: fine 'hue sector', wherein the full hexagon is composed of 36 10-degree sectors, with 0-degrees at the 1200 angle.

• sec.coarse: coarse 'hue sector', wherein the full hexagon is composed of five sectors: blue, bluegreen, green, uvgreen, uv, and uvblue.

References

Chittka L. (1992). The colour hexagon: a chromaticity diagram based on photoreceptor excitations as a generalized representation of colour opponency. Journal of Comparative Physiology A, 170(5), 533-543.

Chittka L, Shmida A, Troje N, Menzel R. (1994). Ultraviolet as a component of flower reflections, and the colour perception of Hymenoptera. Vision research, 34(11), 1489-1508.

Author

Thomas White thomas.white026@gmail.com

Examples

data(flowers)
vis.flowers <- vismodel(flowers,
  visual = "apis", qcatch = "Ei", relative = FALSE,
  vonkries = TRUE, achromatic = "l", bkg = "green"
)
flowers.hex <- colspace(vis.flowers, space = "hexagon")