Rcmdr (version 1.1-2)

scatter3d: Three-Dimensional Scatterplots and Point Identification

Description

The scatter3d function uses the rgl package to draw 3D scatterplots with various regression surfaces. The function identify3d allows you to label points interactively with the mouse: Press the right mouse button (on a two-button mouse) or the centre button (on a three-button mouse), drag a rectangle around the points to be identified, and release the button. Repeat this procedure for each point or set of ``nearby'' points to be identified. To exit from point-identification mode, click the right (or centre) button an empty region of the plot.

Usage

scatter3d(x, y, z, 
    xlab=deparse(substitute(x)), ylab=deparse(substitute(y)),
    zlab=deparse(substitute(z)),
    revolutions=0, bg.col=c("white", "black"), 
    axis.col=if (bg.col == "white") "black" else "white",
    surface.col=c("blue", "green", "orange", "magenta", 
        "cyan", "red", "yellow", "gray"),
    neg.res.col="red", pos.res.col="green", point.col="yellow",
    text.col=axis.col, 
    grid.col=if (bg.col == "white") "black" else "gray",
    fogtype=c("exp2", "linear", "exp", "none"),
    residuals=(length(fit) == 1), surface=TRUE, grid=TRUE, 
    grid.lines=26, df.smooth=NULL, df.additive=NULL,
    sphere.size=1, threshold=0.01, speed=1, fov=60,
    fit="linear", groups=NULL, parallel=TRUE, model.summary=FALSE)
    
identify3d(x, y, z, groups=NULL, labels=1:length(x), 
    col=c("blue", "green", "orange", "magenta", "cyan", "red", "yellow", "gray"),
    offset = ((100/length(x))^(1/3)) * 0.02)

Arguments

x

variable for horizontal axis.

y

variable for vertical axis (response).

z

variable for out-of-screen axis.

xlab, ylab, zlab

axis labels.

revolutions

number of full revolutions of the display.

bg.col

background colour; one of "white", "black".

axis.col

colour for axes; default is "white" for black background, "black" for white background.

surface.col

vector of colours for regression planes, used in the order specified by fit.

neg.res.col, pos.res.col

colours for lines representing negative and positive residuals.

point.col

colour of points.

text.col

colour of axis labels.

grid.col

colour of grid lines on the regression surface(s).

fogtype

type of fog effect; one of "exp2", "linear", "exp", "none".

residuals

plot residuals (TRUE or FALSE); available only when there is one surface plotted.

surface

plot surface(s) (TRUE or FALSE).

grid

plot grid lines on the regression surface(s) (TRUE or FALSE).

grid.lines

number of lines (default, 26) forming the grid, in each of the x and y directions.

df.smooth

degrees of freedom for the two-dimensional smooth regression surface; if NULL (the default), the gam function will select the degrees of freedom for a smoothing spline by generalized

df.additive

degrees of freedom for each explanatory variable in an additive regression; if NULL (the default), the gam function will select degrees of freedom for the smoothing splines by generalized cross-validation; if a positiv

sphere.size

relative sizes of spheres representing points; the actual size is dependent on the number of observations.

threshold

if the actual size of the spheres is less than the threshold, points are plotted instead.

speed

relative speed of revolution of the plot.

fov

field of view (in degrees); controls degree of perspective.

fit

one or more of "linear", "quadratic", "smooth", "additive"; to display fitted surface(s); partial matching is supported -- e.g., c("lin", "quad").

groups

if NULL (the default), no groups are defined; if a factor, a different surface or set of surfaces is plotted for each level of the factor; in this event, the colours in plane.col are used successively for the points, s

parallel

when plotting surfaces by groups, should the surfaces be constrained to be parallel? A logical value, with default TRUE.

model.summary

print summary or summaries of the model(s) fit (TRUE or FALSE).

labels

text labels for the points, one for each point; defaults to the observation indices.

col

colours for the point labels, given by group. There must be at least as many colours as groups; if there are no groups, the first colour is used. Normally, the colours would correspond to the plane.col argument to scatter3d

offset

vertical displacement for point labels (to avoid overplotting by points).

Value

• scatter3d not return a useful value; it is used for its side-effect of creating a 3D scatterplot. indentify3d returns the labels of the identified points.

See Also

rgl.open, gam

Examples

State.x77 <- as.data.frame(state.x77)
with(State.x77, scatter3d(Income, Murder, Illiteracy))
with(State.x77, identify3d(Income, Murder, Illiteracy, labels=row.names(State.x77)))
with(State.x77,  scatter3d(Income, Murder, Illiteracy, fit=c("linear", "quadratic")))