densCols {grDevices} | R Documentation |
densCols
produces a vector containing colors which encode the
local densities at each point in a scatterplot.
densCols(x, y = NULL, nbin = 128, bandwidth,
colramp = colorRampPalette(blues9[-(1:3)]))
blues9
x , y |
the |
nbin |
numeric vector of length one (for both directions) or two
(for x and y separately) specifying the number of equally spaced
grid points for the density estimation; directly used as
|
bandwidth |
numeric vector (length 1 or 2) of smoothing bandwidth(s).
If missing, a more or less useful default is used. |
colramp |
function accepting an integer |
densCols
computes and returns the set of colors that will be
used in plotting.
blues9
is a set of 9 color shades of blue used as the default in
plotting.
densCols
returns a vector of length nrow(x)
that
contains colors to be used in a subsequent scatterplot. Each color
represents the local density around the corresponding point.
Florian Hahne at FHCRC, originally
bkde2D
from package KernSmooth,
and smoothScatter()
which builds on the same
computations as densCols
.
x1 <- matrix(rnorm(1e3), ncol=2)
x2 <- matrix(rnorm(1e3, mean=3, sd=1.5), ncol=2)
x <- rbind(x1,x2)
dcols <- densCols(x)
graphics::plot(x, col = dcols, pch=20, main = "n = 1000")