cloud {lattice}  R Documentation 
Draws 3d scatter plots and surfaces.
cloud(formula, data, aspect = c(1, 1), scales = list(distance = rep(1, 3), arrows = TRUE), zlab, zlim, zoom = 0.8, ...) wireframe(formula, data, at = pretty(z, cuts), col.regions, alpha.regions, drape = FALSE, shade = FALSE, pretty = FALSE, colorkey = any(drape), cuts = 70, zoom, scales, ..., col.regions)
formula 
a formula of the form z ~ x * y  g1 * g2 * ... , where
z is a numeric response, and x , y are numeric
values. g1, g2, ... , if present, are conditioning variables
used for conditioning, and must be either factors or shingles. In
the case of wireframe , calculations are based on the
assumption that the x and y values are evaluated on a
rectangular grid defined by their unique values. The grid points
need not be equally spaced.
For wireframe , x , y and z may also be
matrices (of the same dimension), in which case they are taken to
represent a 3D surface parametrized on a 2D grid (e.g., a sphere).
Conditioning is not possible with this feature. See details below.
Missing values are allowed, either as NA values in the
z vector, or missing rows in the data frame (note however
that in that case the X and Y grids will be determined only by the
available values). For a grouped display (producing multiple
surfaces), missing rows are not allowed, but NA 's in z
are.
As an extension to partially support the form used in filled.contour and image , formula can be a
matrix.

data 
data frame in which variables are evaluated. Ignored is
formula is not really a formula object.

aspect 
vector of length 2, giving the relative aspects of the ysize/xsize and zsize/xsize of the enclosing cube. 
scales 
a list describing the scales. As with other high level functions
(see xyplot for details), this list can contain
parameters in name=value form. It can also contain components with
the special names x , y and z , which can be
similar lists with axisspecific values overriding the ones
specified in scales .
The most common use for this argument is to set arrows=FALSE ,
which causes tick marks and labels to be used instead of arrows
being drawn (the default). Both can be suppressed by
draw=FALSE .
Other components that work in the scales argument of
xyplot etc. should also work here (as long as they make
sense), including explicit specification of tick mark locations and
labels. (Not everything is implemented yet, but if you find
something that should work but doesn't, feel free to bug the
maintainer.)
Note, however, that for these functions scales cannot contain
information that is specific to particular panels. If you really
need that, consider using the scales.3d argument of
panel.cloud .

zlab 
label describing the z variable. Similar to xlab and
ylab in other high level functions

zlim 
limits for the zaxis. Similar to xlim and ylim in
other high level functions

zoom 
factor by which to scale the picture. Useful to get the variable names into the plot. This is actually only used in the default prepanel function. 
drape 
logical, whether the wireframe is to be draped in color. If
TRUE , the height of a facet is used to determine its color in
a manner similar to the coloring scheme used in
levelplot . Otherwise, the background color is used to
color the facets. This argument is ignored if shade=TRUE .

shade 
logical, whether the wireframe is to be rendered as being
illuminated from a light source. See panel.3dwire for
details

at, col.regions, alpha.regions 
these arguments are analogous to those in
levelplot . if drape=TRUE , at gives the
vector of cutpoints where the colors change, and col.regions
the vector of colors to be used in that case. alpha.regions
determines the alphatransparency on supporting devices. These are
passed down to the panel function, and also used in the colorkey if
appropriate. The default for col.regions and
alpha.regions is derived the Trellis setting ``regions''

cuts 
if at is unspecified, the approximate number of cutpoints if
drape=TRUE

pretty 
whether automatic choice of cutpoints should be prettfied 
colorkey 
logical indicating whether a color key should be drawn
alongside, or a list describing such a key. See
levelplot for details.

... 
other arguments, passed to the panel function. In particular, the
arguments distance , perspective , screen and
R.mat are very important in determining the 3D
display. These arguments are described in detail in the help page
for panel.cloud

These functions produce three dimensional plots in each panel (as long
as the default panel functions are used). The orientation is obtained
as follows: the data are scaled to fall within a bounding box that is
contained in the [0.5, 0.5] cube (even smaller for nondefault values
of aspect
). The viewing direction is given by a sequence of
rotations specified by the screen
argument, starting from the
positive Zaxis. The viewing point (camera) is located at a distance
of 1/distance
from the origin. If perspective=FALSE
,
distance
is set to 0 (i.e., the viewing point is at an infinite
distance).
cloud
draws a 3D Scatter Plot, while wireframe
draws a
3D surface (usually evaluated on a grid). Multiple surfaces can be
drawn by wireframe
using the groups
argument (although
this is of limited use because the display is incorrect when the
surfaces intersect). Specifying groups
with cloud
results in a panel.superpose
like effect (via
panel.3dscatter
).
wireframe
can optionally render the surface as being
illuminated by a light source (no shadows though). Details can be
found in the help page for panel.3dwire
. Note that
although arguments controlling these are actually arguments for the
panel function, they can be supplied to cloud
and
wireframe
directly.
For single panel plots, wireframe
can also plot parametrized
3D surfaces (i.e., functions of the form f(u,v) = (x(u,v), y(u,v),
z(u,v)), where values of (u,v) lie on a rectangle. The simplest
example of this sort of surface is a sphere parametrized by latitude
and longitude. This can be achieved by calling wireframe
with a
formula
of the form z~x*y
, where x
, y
and
z
are all matrices of the same dimension, representing the
values of x(u,v), y(u,v) and z(u,v) evaluated on a discrete
rectangular grid (the actual values of (u,v) are irrelevant).
When this feature is used, the heights used to calculate drape
colors or shading colors are no longer the z
values, but the
distances of (x,y,z)
from the origin.
Note that this feature does not work with groups
,
subscripts
, subset
, etc. Conditioning variables are also
not supported in this case.
The algorithm for identifying which edges of the bounding box are
`behind' the points doesn't work in some extreme situations. Also,
panel.cloud
tries to figure out the optimal location of the
arrows and axis labels automatically, but can fail on occasion
(especially when the view is from ``below'' the data). This can be
manually controlled by the scpos
argument in
panel.cloud
.
These and all other high level Trellis functions have several other
arguments in common. These are extensively documented only in the
help page for xyplot
, which should be consulted to learn more
detailed usage.
An object of class ``trellis''. The `update' method can be used to update components of the object and the `print' method (usually called by default) will plot it on an appropriate plotting device.
Deepayan Sarkar Deepayan.Sarkar@Rproject.org
xyplot
, levelplot
,
panel.cloud
,
Lattice
## volcano ## 87 x 61 matrix wireframe(volcano, shade = TRUE, aspect = c(61/87, 0.4), light.source = c(10,0,10)) g < expand.grid(x = 1:10, y = 5:15, gr = 1:2) g$z < log((g$x^g$g + g$y^2) * g$gr) wireframe(z ~ x * y, data = g, groups = gr, scales = list(arrows = FALSE), drape = TRUE, colorkey = TRUE, screen = list(z = 30, x = 60)) cloud(Sepal.Length ~ Petal.Length * Petal.Width  Species, data = iris, screen = list(x = 90, y = 70), distance = .4, zoom = .6) par.set < list(axis.line = list(col = "transparent"), clip = list(panel = FALSE)) print(cloud(Sepal.Length ~ Petal.Length * Petal.Width, data = iris, cex = .8, groups = Species, main = "Stereo", screen = list(z = 20, x = 70, y = 3), par.settings = par.set), split = c(1,1,2,1), more = TRUE) print(cloud(Sepal.Length ~ Petal.Length * Petal.Width, data = iris, cex = .8, groups = Species, main = "Stereo", screen = list(z = 20, x = 70, y = 0), par.settings = par.set), split = c(2,1,2,1))