| levelplot {lattice} | R Documentation |
Draw Level Plots and Contour plots.
levelplot(formula,
at,
col.regions = trellis.par.get("regions")$col,
colorkey = region,
contour = FALSE,
cuts = 15,
labels = format(at),
pretty = FALSE,
region = TRUE,
...)
contourplot(formula, 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.
|
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 <- 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()