scatter3d {Rcmdr}R Documentation

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 cross-validation; if a positive number, a fixed regression spline will be fit with the specified degrees of freedom.
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 positive number or a vector of two positive numbers, fixed regression splines will be fit with the specified degrees of freedom for each term.
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, surfaces, and residuals corresponding to each level of the factor.
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.

Note

You have to install the rgl and mgcv packages to produce 3D plots.

Author(s)

John Fox jfox@mcmaster.ca

See Also

rgl.open, gam

Examples

    ## Not run: 
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")))
    
## End(Not run)

[Package Rcmdr version 1.1-6 Index]