specplot {colorspace} | R Documentation |
Visualization of color palettes (given as hex codes) in RGB and/or HCL coordinates.
specplot(x, rgb = TRUE, hcl = TRUE, fix = TRUE, cex = 1, type = "l", lwd = 2 * cex, lty = 1, pch = NULL, legend = TRUE, palette = TRUE, plot = TRUE)
x |
character vector containing color hex codes. |
rgb |
logical or color specification. Should the RGB spectrum be visualized? Can also be a vector of three colors for the R/G/B coordinates. |
hcl |
logical or color specification. Should the HCL spectrum be visualized? Can also be a vector of three colors for the H/C/L coordinates. |
fix |
logical. Should the hues be fixed to be on a smooth(er) curve? For details see below. |
cex |
numeric. Character extension for figure axes and labels. |
type, lwd, lty, pch |
plotting parameters passed to
|
legend |
logical. Should legends for the coordinates be plotted? |
palette |
logical. Should the given palette |
plot |
logical. Should the RGB and/or HCL coordinates be plotted? |
The function specplot
transforms a given color palette in hex
codes into their RGB (sRGB
) or
HCL (polarLUV
) coordinates. As the hues for
low-chroma colors are not (or poorly) identified, by default a smoothing
is applied to the hues (fix = TRUE
). Also, to avoid jumps from
0 to 360 or vice versa, the hue coordinates are shifted suitably.
By default (plot = TRUE
) the resulting RGB and HCL coordinates
are visualized by simple line plots along with the color palette x
itself.
specplot
invisibly returns a list with components
RGB |
a matrix of sRGB coordinates, |
HCL |
a matrix of HCL coordinates, |
hex |
original color palette |
Reto Stauffer, Achim Zeileis
Zeileis A, Hornik K, Murrell P (2009). Escaping RGBland: Selecting Colors for Statistical Graphics. Computational Statistics & Data Analysis, 53, 3259–3270. doi: 10.1016/j.csda.2008.11.033 Preprint available from https://eeecon.uibk.ac.at/~zeileis/papers/Zeileis+Hornik+Murrell-2009.pdf.
Stauffer R, Mayr GJ, Dabernig M, Zeileis A (2015). Somewhere over the Rainbow: How to Make Effective Use of Colors in Meteorological Visualizations. Bulletin of the American Meteorological Society, 96(2), 203–216. doi: 10.1175/BAMS-D-13-00155.1
## spectrum of the (in)famous RGB rainbow palette specplot(rainbow(100)) ## spectrum of HCL-based palettes: qualitative/sequential/diverging specplot(rainbow_hcl(100)) specplot(sequential_hcl(100)) specplot(diverge_hcl(100)) ## return computed RGB and HCL coordinates res <- specplot(rainbow(10), plot = FALSE) print(res)