lattice (version 0.17-13)

level.colors: A function to compute false colors representing a numeric or categorical variable

Description

Calculates false colors from a numeric variable (including factors, using their numeric codes) given a color scheme and breakpoints.

Usage

level.colors(x, at, col.regions, colors = TRUE, ...)

Arguments

x

A numeric or factor variable

at

A numeric variable of breakpoints where colors change

col.regions

A specification of the colors to be used. This could be either a vector of colors, or a function that produces a vector of colors when called with a single argument giving the number of colors.

colors

logical indicating whether colors should be computed and returned. If FALSE, only the indices representing which interval (among those defined by at) each value in x falls into is returned.

...

Extra arguments, ignored.

Value

• 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.

See Also

levelplot

Examples

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], ...)
       })