Functions generating color palettes useable with R graphical functions, in particular with
sp::spplot(). These palettes are continuous, contrast being accentuated by darkening
and lightening extrem values. prevR.demo.pal plot the available palettes.
prevR.colors.qgis.pal export a palette in a text file readable by Quantum GIS,
an open-source mapping software.
Usage
prevR.colors.blue(n)
prevR.colors.blue.inverse(n)
prevR.colors.gray(n)
prevR.colors.gray.inverse(n)
prevR.colors.green(n)
prevR.colors.green.inverse(n)
prevR.colors.red(n)
prevR.colors.red.inverse(n)
prevR.demo.pal(n, border = if (n < 32) "light gray" else NA, main = NULL)
prevR.colors.qgis.pal(file, at, pal = "red", inverse = FALSE)
Arguments
n
number of different colors in the palette.
border
border color.
main
title.
file
file name with extension.
at
list of values of the palette.
pal
color palette to use ("red", "green", "blue" or "gray").
The other functions return a list of colors coded in hexadecimal.
Details
prevR.colors.red() produces a color gradation from white/yellow to red/dark red.
prevR.colors.blue() produces a color gradation from light blue to dark blue.
prevR.colors.green() produces a color gradation from light green to dark green.
prevR.colors.gray() produces a color gradation from white/light gray to dark gray/black.
Functions with a suffix .inverse produce the same color gradation, but from dark colors to light ones.
See Also
Other color palettes are available in R. See for example
grDevices::rainbow() or the package RColorBrewer.
# NOT RUN {prevR.demo.pal(25)
prevR.colors.red(5)
col2rgb(prevR.colors.red(5))
# }# NOT RUN { prevR.colors.qgis.pal('palette.txt', seq(0,25,length.out=100), 'red')
# }# NOT RUN {# }