Nothing
#' Dichromatic colour space
#'
#' Calculates coordinates and colorimetric variables that represent reflectance spectra
#' in a dichromatic colour space.
#'
#' @param vismodeldata (required) quantum catch color data. Can be either the result
#' from [vismodel()] or independently calculated data (in the form of a data frame
#' with two columns named 's' and 'l', representing a dichromatic viewer's receptors).
#'
#' @return A data frame of class [`colspace`] consisting of the following columns:
#' * `s`, `l`: the quantum catch data used to calculate
#' the remaining variables.
#' * `x`: the coordinate of the stimulus along a segment
#' * `r.vec`: the r vector (saturation, distance from the center).
#'
#' @examples
#' data(flowers)
#' vis.flowers <- vismodel(flowers, visual = "canis")
#' di.flowers <- colspace(vis.flowers, space = "di")
#' @author Thomas White \email{thomas.white026@@gmail.com}
#'
#' @export
#'
#' @keywords internal
#'
#' @references Kelber A, Vorobyev M, Osorio D. (2003). Animal colour vision -
#' behavioural tests and physiological concepts. Biological Reviews, 78,
#' 81 - 118.
dispace <- function(vismodeldata) {
dat <- vismodeldata
# if object is vismodel:
if (is.vismodel(dat)) {
# check if trichromat
if (attr(dat, "conenumb") < 2) {
stop("vismodel input is not dichromatic", call. = FALSE)
}
if (attr(dat, "conenumb") > 2) {
warning("vismodel input is not dichromatic, considering first two receptors only", call. = FALSE)
attr(vismodeldata, "data.maxqcatches") <- attr(vismodeldata, "data.maxqcatches")[, seq_len(2)]
}
# check if relative
if (!attr(dat, "relative")) {
dat <- dat[, 1:2]
dat <- dat / rowSums(dat)
class(dat) <- class(vismodeldata)
warning("Quantum catch are not relative, and have been transformed", call. = FALSE)
attr(vismodeldata, "relative") <- TRUE
}
} else { # if not, check if it has more (or less) than 2 columns
if (ncol(dat) < 2) {
stop("Input data is not a ", dQuote("vismodel"), " object and has fewer than two columns", call. = FALSE)
}
if (ncol(dat) == 2) {
warning("Input data is not a ", dQuote("vismodel"),
" object; treating columns as standardized quantum catch for ",
dQuote("s"), " and ", dQuote("l"), " receptors, respectively",
call. = FALSE
)
}
if (ncol(dat) > 2) {
warning("Input data is not a ", dQuote("vismodel"),
" object *and* has more than two columns; treating the first two columns as standardized quantum catch for ",
dQuote("s"), ", and ", dQuote("l"), " receptors, respectively",
call. = FALSE
)
attr(vismodeldata, "data.maxqcatches") <- attr(vismodeldata, "data.maxqcatches")[, seq_len(2)]
}
dat <- dat[, 1:2]
names(dat) <- c("s", "l")
# Check that all rows sum to 1 (taking into account R floating point issue)
if (!isTRUE(all.equal(rowSums(dat), rep(1, nrow(dat)), check.attributes = FALSE))) {
dat <- dat / rowSums(dat)
warning("Quantum catch are not relative, and have been transformed", call. = FALSE)
attr(vismodeldata, "relative") <- TRUE
}
}
if (all(c("s", "l") %in% names(dat))) {
s <- dat[, "s"]
l <- dat[, "l"]
} else {
warning("Could not find columns named ", dQuote("s"), ", and ",
dQuote("l"), ", using first two columns instead.",
call. = FALSE
)
s <- dat[, 1]
l <- dat[, 2]
}
# coordinate
ref <- matrix(c(-1 / sqrt(2), 1 / sqrt(2)), nrow = 2, ncol = 1)
x <- bary2cart(ref, cbind(s, l))
# colorimetrics?
r.vec <- abs(x)
res <- data.frame(s, l, x, r.vec, row.names = rownames(dat))
class(res) <- c("colspace", "data.frame")
# Descriptive attributes (largely preserved from vismodel)
attr(res, "clrsp") <- "dispace"
attr(res, "conenumb") <- 2
attr(res, "qcatch") <- attr(vismodeldata, "qcatch")
attr(res, "visualsystem.chromatic") <- attr(vismodeldata, "visualsystem.chromatic")
attr(res, "visualsystem.achromatic") <- attr(vismodeldata, "visualsystem.achromatic")
attr(res, "illuminant") <- attr(vismodeldata, "illuminant")
attr(res, "background") <- attr(vismodeldata, "background")
attr(res, "relative") <- attr(vismodeldata, "relative")
attr(res, "vonkries") <- attr(vismodeldata, "vonkries")
# Data attributes
attr(res, "data.visualsystem.chromatic") <- attr(vismodeldata, "data.visualsystem.chromatic")
attr(res, "data.visualsystem.achromatic") <- attr(vismodeldata, "data.visualsystem.achromatic")
attr(res, "data.background") <- attr(vismodeldata, "data.background")
maxqcatches <- attr(vismodeldata, "data.maxqcatches")
if (!is.null(maxqcatches) && ncol(maxqcatches) == 2) {
maxqcatches <- maxqcatches / rowSums(maxqcatches)
attr(res, "data.maxgamut") <- bary2cart(ref, maxqcatches)
} else {
attr(res, "data.maxgamut") <- NA
}
res
}
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.