Convert JND distances into perceptually-corrected Cartesian coordinates

Converts a coldist() output into Cartesian coordinates that are perceptually-corrected (i.e. Euclidean distances = JND distances)

jnd2xyz(
  coldistres,
  center = TRUE,
  rotate = TRUE,
  rotcenter = c("mean", "achro"),
  ref1 = "l",
  ref2 = "u",
  axis1 = c(1, 1, 0),
  axis2 = c(0, 0, 1)
)

Arguments

coldistres	(required) the output from a coldist() call.
center	logical indicating if the data should be centered on its centroid (defaults to TRUE).
rotate	logical indicating if the data should be rotated (defaults to TRUE).
rotcenter	should the vectors for rotation be centered in the achromatic center ("achro") or the data centroid ("mean", the default)?
ref1	the cone to be used as a the first reference. May be NULL (for no first rotation in the 3-dimensional case) or must match name in the original data that was used for coldist(). Defaults to 'l'.
ref2	the cone to be used as a the second reference. May be NULL (for no first rotation in the 3-dimensional case) or must match name in the original data that was used for coldist(). Defaults to 'u'. (only used if data has 3 dimensions).
axis1	A vector of length 3 composed of 0's and 1's, with 1's representing the axes (x,y,z) to rotate around. Defaults to c(1,1,0), such that the rotation aligns with the xy plane (only used if data has 2 or 3 dimensions). Ignored if ref1 is NULL (in 3-dimensional case only)
axis2	A vector of length 3 composed of 0's and 1's, with 1's representing the axes (x,y,z) to rotate around. Defaults to c(0,0,1), such that the rotation aligns with the z axis (only used if data has 3 dimensions). Ignored if ref2 is NULL (in 3-dimensional case only)

References

Pike, T.W. (2012). Preserving perceptual distances in chromaticity diagrams. Behavioral Ecology, 23, 723-728.

Maia, R., White, T. E., (2018) Comparing colors using visual models. Behavioral Ecology, ary017 doi: 10.1093/beheco/ary017

Author

Rafael Maia rm72@zips.uakron.edu

Examples

data(flowers)
vis.flowers <- vismodel(flowers)
cd.flowers <- coldist(vis.flowers)
#> Warning: Quantum catch are relative, distances may not be meaningful
#> Calculating noise-weighted Euclidean distances
jnd2xyz(cd.flowers)
#>                                     x           y           z
#> Goodenia_heterophylla      1.53718118 -5.46159458   7.0514924
#> Goodenia_geniculata       -0.59310315 -2.65363603  -6.4010132
#> Goodenia_gracilis         -5.35249990 11.57575094 -22.9160486
#> Xyris_operculata           3.16707188 -1.34474081  -3.8107457
#> Eucalyptus_sp             -0.03134485 -3.32415657   3.2303526
#> Faradaya_splendida        -1.29639206  0.46232996  -2.7868330
#> Gaultheria_hispida         2.50443028 -4.15752823  -1.9683611
#> Geitonoplesium_cymosum     8.60482980 -7.04418816   8.3554048
#> Euryomyrtus_ramosissima   -2.05359168 -0.37250955   5.1435291
#> Genista_linifolia         -0.58649346 -1.81156877  -2.3301504
#> Genista_monspessulana     -0.14356310 -3.20065722  -2.8881030
#> Geranium_sp                7.78622533  6.78399481  11.3644393
#> Glycine_clandestina       -0.12166618 -2.82133147  -4.9021716
#> Gompholobium_ecostatum_1   2.32014969  0.01343586   5.9004073
#> Gompholobium_ecostatum_2  -0.35597946 -2.19758735  -6.2491817
#> Gompholobium_grandiflorum -3.21092428  4.62986466  -6.6125576
#> Gompholobium_huegelii      0.74658571 -1.85959598   6.5006043
#> Gompholobium_virgatum      1.64743911 -1.26454780   6.2822410
#> Gonocarpus_humilis         0.12111582 -3.92547632  -3.4985432
#> Gonocarpus_teucrioides    -0.10675135 -2.22322988   2.3336963
#> Hibbertia_obtusifolia     -0.52778583 -1.45422302  -1.8375439
#> Zieria_arborescens        -4.71335405  9.56162650   9.4440349
#> Goodenia_lanata           -4.52523519  7.81353151 -13.6100744
#> Goodenia_ovata            -3.57431799 10.83505159  10.3387120
#> Goodenia_rotundifolia      2.98213580 -6.44640439   6.1896101
#> Grevillea_buxifolia        2.59032352 -3.64441651   1.6394104
#> Grevillea_steiglitziana   -4.71094829  5.35795883  -0.6206625
#> Grevillea_oleoides        -0.10128482 -3.18245178  -4.3953309
#> Gymnostachys_anceps       -4.88100844 10.57079928  -9.2576390
#> Hakea_actites              1.28591187 -6.46308298   8.7478471
#> Hardenbergia_violaceae    -1.56087094  0.54787062  -3.1446578
#> Hibbertia_acicularis       0.05050284 -3.55267520   2.0046822
#> Hibbertia_bracteata        7.58267580 -2.46048123   1.5050828
#> Hibbertia_empetrifolia    -4.03056849  8.40782674   9.5245585
#> Hibbertia_procumbens       0.11607407 -3.47828825  -0.6629848
#> Hibbertia_linearis        -0.56496920 -2.21566927  -7.6635029