ice_pal: Sea ice colours

In palr: Colour Palettes for Data

Sea ice colours

Description

Colours for sea ice.

Usage

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)

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

Value

colours, palette, or function, see Details

References

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

Examples

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

palr documentation built on Aug. 5, 2026, 9:07 a.m.