Sea ice colours — ice

Colours for sea ice.

ice_pal(x, palette = FALSE, alpha = 1, ..., amsre = FALSE)

icePal(x, palette = FALSE, alpha = 1, ...)

Arguments

x: a vector of data values or a single num (n)
palette: logical, if TRUE return a list with matching colours and values
alpha: value in 0,1 to specify opacity
...: currently ignored
amsre: use old AMSRE colours (`FALSE` by default)

Value

colours, palette, or function, see Details

Details

The palette functions operate in 3 modes: 1) n colours - Pal(6) - returns 6 colours from the palette 2) data - Pal(c(10, 50, 100)) - return colours for 3 ice concentrations 3) palette - Pal(palette = TRUE) - return the full palette and breaks

References

amsre colours derived from http://www.iup.uni-bremen.de/seaice/amsr/., nsidc colours extracted in data-raw/.

Examples

if (FALSE) {
library(raster)
r <- raster(system.file("extdata", "nt_20140320_f17_v01_s.bin", package = "graticule") )
icp <- ice_pal(palette = TRUE)
## The AMSR colours
plot(r, col = icp$col, zlim = range(icp$breaks),
main = sprintf("NSIDC ice \\% %s", format(getZ(r))))
}