lattice (version 0.5-4)

levelplot: Level Plots

Description

Draw Level Plots and Contour plots.

Usage

levelplot(formula, data,
          at,
          col.regions = trellis.par.get("regions")$col,
          colorkey = region,
          contour = FALSE,
          cuts = 15,
          labels = format(at),
          pretty = FALSE,
          region = TRUE,
          ...)
contourplot(formula, data, at,
            contour = TRUE,
            cuts = 7,
            pretty = TRUE,
            ...)

Arguments

formula

a formula of the form z ~ x * y | g1 * g2 * ..., where z is a numeric response, and x, y are numeric values evaluated on a rectangular grid. g1,g2,..., if present, must be either factor

data

optional data frame in which variables are to be evaluated

at

numeric vector giving breaks along the range of z. Contours (if any) will be drawn at these heights, and the regions in between would be colored using col.regions.

col.regions

color vector to be used if regions is TRUE

colorkey

logical specifying whether a color key is to be drawn alongside the plot, or a list describing the color key. The list may contain the following components:

space location of the colorkey, can be one of ``left'', ``right'', `

contour

logical, whether to draw contour lines.

cuts

number of levels the range of z would be divided into

labels

character vector of labels for contour lines, not implemented yet.

pretty

logical, whether to use pretty labels

region

logical, whether regions between contour lines should be filled

...

other arguments

synopsis

levelplot(formula, data = parent.frame(), aspect = "fill", layout = NULL, panel = "panel.levelplot", prepanel = NULL, scales = list(), strip = TRUE, groups = NULL, xlab, xlim, ylab, ylim, at, col.regions = terrain.colors(length(at) - 1), colorkey = NULL, contour = FALSE, cuts = 15, labels = format(at), pretty = FALSE, region = TRUE, ..., subscripts = TRUE, subset = TRUE) contourplot(formula, data = parent.frame(), aspect = "fill", layout = NULL, panel = "panel.levelplot", prepanel = NULL, scales = list(), strip = TRUE, groups = NULL, xlab, xlim, ylab, ylim, cuts = 7, contour = TRUE, pretty = TRUE, region = FALSE, ..., subscripts = TRUE, subset = TRUE)

Details

These and all other high level Trellis functions have several arguments in common. These are extensively documented only in the help page for xyplot, which should be consulted to learn more detailed usage.

See Also

xyplot, Lattice, panel.levelplot

Examples

x <- seq(pi/4, 5*pi, length = 100)
y <- seq(pi/4, 5*pi, length = 100)
r <- as.vector(sqrt(outer(x^2, y^2, "+")))
grid <- expand.grid(x=x, y=y)
grid$z <- cos(r^2) * exp(-r/(pi^3))
levelplot(z~x*y, grid, cuts = 50, xlab="", ylab="",
          main="Weird Function", colorkey = FALSE)
levelplot(z~x*y, grid, cuts = 50, scales=list(log="e"), xlab="",
          ylab="", main="Weird Function", sub="with log scales",
          colorkey = FALSE, region = TRUE)
#S+ example
data(environmental)
attach(environmental)
ozo.m <- loess((ozone^(1/3)) ~ wind * temperature * radiation,
       parametric = c("radiation", "wind"), span = 1, degree = 2)
w.marginal <- seq(min(wind), max(wind), length = 50)
t.marginal <- seq(min(temperature), max(temperature), length = 50)
r.marginal <- seq(min(radiation), max(radiation), length = 4)
wtr.marginal <- list(wind = w.marginal, temperature = t.marginal,
        radiation = r.marginal)
grid <- expand.grid(wtr.marginal)
grid[, "fit"] <- c(predict(ozo.m, grid))
contourplot(fit ~ wind * temperature | radiation, data = grid,
          cuts = 10, region = TRUE,
          xlab = "Wind Speed (mph)",
          ylab = "Temperature (F)",
          main = "Cube Root Ozone (cube root ppb)",
          col.regions = trellis.par.get("regions")$col)
detach()