D_level.colors {lattice} | R Documentation |
Calculates false colors from a numeric variable (including factors, using their numeric codes) given a color scheme and breakpoints.
level.colors(x, at, col.regions, colors = TRUE, ...)
x |
A numeric or |
at |
A numeric variable of breakpoints defining intervals along
the range of |
col.regions |
A specification of the colors to be assigned to
each interval defined by |
colors |
logical indicating whether colors should be computed
and returned. If |
... |
Extra arguments, ignored. |
If at
has length n, then it defines n-1 intervals. Values of
x
outside the range of at
are not assigned to an
interval, and the return value is NA
for such values.
Colors are chosen by assigning a color to each of the n-1 intervals.
If col.regions
is a palette function (such as
topo.colors
, or the result of calling
colorRampPalette
), it is called with n-1 as an argument
to obtain the colors. Otherwise, if there are exactly n-1 colors in
col.regions
, these get assigned to the intervals. If there are
fewer than n-1 colors, col.regions
gets recycled. If there are
more, a more or less equally spaced (along the length of
col.regions
) subset is chosen.
A vector of the same length as x
. Depending on the
colors
argument, this could be either a vector of colors (in
a form usable by R), or a vector of integer indices representing
which interval the values of x
fall in.
Deepayan Sarkar deepayan.sarkar@r-project.org
depth.col <- with(quakes, level.colors(depth, at = do.breaks(range(depth), 30), col.regions = terrain.colors)) xyplot(lat ~ long | equal.count(stations), quakes, strip = strip.custom(var.name = "Stations"), colours = depth.col, panel = function(x, y, colours, subscripts, ...) { panel.xyplot(x, y, pch = 21, col = "transparent", fill = colours[subscripts], ...) })