scatter3dHH {RcmdrPlugin.HH}

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.

This is a revision of the Rcmdr scatter3d to add the ability to plot squared residuals.

Usage

scatter3dHH(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,
    squares = FALSE, square.color = "gray", coef.ratio = 1, ...)

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).

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.

squares

logical. If TRUE, the residuals are plotted as squares. The sum of the area of the squares is the "residual sum of squares". If FALSE, the residuals are plotted as vertical lines.

square.color

color for the squares.

coef.ratio

number, defaults to 1. Settig coef.ratio to a number other than 1 is a primitive way of plotting squared pseudo-residuals that are not the least-squares residuals. The reason for displaying non-least-squares residuals is to compare them to the least-squares residuals and thus get a 3d visual image of what minimizing the sum of squares actually means.

...

other arguments are ignored.

Value

scatter3d not return a useful value; it is used for its side-effect of creating a 3D scatterplot. Identify3d 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 [e-mail]. Squared residuals added by Richard M. Heiberger <[e-mail]>.

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)