This function returns a color value for each row of the 3-column dataset supplied, by transforming the input data and using it as RGB values.
Arguments
- data
Matrix or data frame with 3 numeric columns.
- trans
Either "none" (defaut, histogram is rescaled) or "rank" (histogram is flattened).
- order
Integer from 1 to 6, each denoting a unique permutation of variables-to-color band mapping. Under the default value of 1, the three variables in `data` are respectively mapped onto the R, G, and B bands of colorspace.
- inversion
Integer from 1 to 8, each denoting a unique combination of variables to reverse before mapping. Under the default value of 1, all three variables are mapped with positive values at the high end of the color band. Together with the `order` parameter, this allows all possible 48 unique mappings of a given set of variables onto 3D colorspace.
- opacity
Not currently used.
Examples
d <- expand.grid(x = 1:49, y = 1:49)
d$z <- cos(sqrt((d$x-25)^2 + (d$y-25)^2))
plot(d[, 1:2], col = colors3d(d), pch = 15, cex = 2)
plot(d[, 1:2], col = colors3d(d, order = 2, inversion = 2), pch = 15, cex = 2)
