pals (version 1.8)

pal.volcano: Show a colormap with a surface of volcano elevation

Description

Some palettes with dark colors at one end of the palette hide the shape of the volcano in the dark colors. Viridis is bad.

Usage

pal.volcano(pal, n = 100, main = "")

Value

None.

Arguments

pal

A palette function or a vector of colors.

n

The number of colors to display for palette functions.

main

Main title

Details

What to look for:

1. Can you locate the highest point on the volcano?

2. Are the upper-right and lower-right corners the same elevation?

3. Do any Mach bands circle the peak?

Examples

pal.volcano(parula)
pal.volcano(brewer.rdbu) # Mach banding is bad
pal.volcano(warmcool, main="warmcool") # No Mach band 
pal.volcano(rev(viridis(100))) # Bad: peak position is hidden