Used to colour HoldridgeHexagons(), and may also be used to aid the interpretation of PET + precipitation data in any graphical context.

HoldridgeHypsometricCol(pet, prec, opacity = NA)


pet, prec

Numeric vectors giving potential evapotranspiration ratio and annual precipitation (in mm).


Opacity level to be converted to the final two characters of an RGBA hexadecimal colour definition, e.g. #000000FF. Specify a character string, which will be interpreted as a hexadecimal alpha value and appended to the six RGB hexadecimal digits; a numeric in the range 0 (transparent) to 1 (opaque); or NA, to return only the six RGB digits.


Character vector listing RGB or (if opacity != NA) RGBA values corresponding to each PET-precipitation value pair.


Palette derived from the hypsometric colour scheme presented at Shaded Relief.

See also

Other Holdridge plotting functions: AddToHoldridge(), HoldridgePlot(), holdridgeClasses, holdridge


HoldridgePlot(hex.col = HoldridgeHypsometricCol)

VeryTransparent <- function(...) HoldridgeHypsometricCol(..., opacity = 0.3)
HoldridgePlot(hex.col = VeryTransparent)
pet <- holdridge$PET
prec <- holdridge$Precipitation
ptCol <- HoldridgeHypsometricCol(pet, prec)
HoldridgePoints(pet, prec, pch = 21, bg = ptCol)