levelplot {lattice} | R Documentation |
Draw Level Plots and Contour plots.
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, ...)
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 factors or shingles.
Calculations are based on the assumption that all x and y values are evaluated on a grid (defined by (unique(x)) and
(unique(y)) . The function will not return an error if this is
not true, but the display might be nonsense.
However, the x and y values need not be equally spaced. See example below with log scales. As an extension to partially support the form used in filled.contour and image , formula can be a
matrix.
|
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'', ``top'' and ``bottom''. Defaults to ``right''.
x,y location, unused
col vector of colors
at numeric vector specifying where the colors change. must be
of length 1 more than the col vector.
labels a character vector for labelling the at values,
or more commonly, a list of components labels, at, cex, col,
font describing label positions.
tick.number approximate number of ticks.
corner interacts with x, y; unimplemented
width width of the key in terms of character widths
height length of key w.r.t side of plot.
|
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 |
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.
Deepayan Sarkar deepayan@stat.wisc.edu
xyplot
, Lattice
, panel.levelplot
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()