the number of gray colors (\(\ge 1\)) to be in the
palette.
start
starting gray level in the palette (should be between
0 and 1 where zero indicates "black" and one
indicates "white").
end
ending gray level in the palette.
gamma
the gamma correction.
alpha
the opacity, is specified.
rev
logical indicating whether the ordering of the colors should
be reversed.
Value
A vector of n gray colors.
Details
The function gray.colors chooses a series of n
gamma-corrected gray levels between start and end:
seq(start^gamma, end^gamma, length = n)^(1/gamma).
The returned palette contains the corresponding gray colors.
This palette is used in barplot.default.