Rotating three-dimensional plot

General function to draw a rgl-based rotating 3D scatterplot.

Usage

spinplot(x, y, z, 
         scaling = c("abc", "aaa"), 
         rem.lin.trend = FALSE, 
         uncor.vars = FALSE, 
         fit.ols = FALSE, 
         fit.smooth = FALSE, 
         span = 0.75, 
         ngrid = 25, 
         markby, 
         pch.points = 1, 
         col.points = "black", 
         cex.points = 1,
         col.axis   = "gray50", 
         col.smooth = "limegreen", 
         col.ols    = "lightsteelblue",
         background = "white", 
         ...)

Arguments

x: a vector of values for the variable in the horizontal (H) screen axis.
y: a vector of values for the variable in the vertical (V) screen axis.
z: a vector of values for the variable in the out-of-screen (O) axis.
scaling: the scaling applied. Two possible values are "abc" and "aaa".
rem.lin.trend: a logical specifying if the linear trend should be remove. If TRUE then the vertical axis is replaced by e(V|H,O), i.e. the residuals from a linear fit of the vertical axis variable on the others.
uncor.vars: a logical specifying if uncorrelated H and O variables should be used. If TRUE then the O variable is replaced by e(O|H), i.e. the residuals of the regression of O on H, hence obtaining a pair of uncorrelated variables.
fit.ols: a logical specifying if a fitted OLS plane should be included.
fit.smooth: a logical specifying if a nonparametric smoothing plane should be included.
span: the span used by loess to fit the polynomial surface.
ngrid: the number of grid points to use for displaing the fitted plane.
markby: a variable (usually a factor) to be used for marking the points.
pch.points: a vector of symbols for marking the points.
col.points: a vector of colors for marking the points.
cex.points: the cex for points.
col.axis: the color of the axis.
col.ols: the color to be used for drawing the OLS plane.
col.smooth: the color to be used for drawing the smoothing plane.
background: the color of background space.
...: catch further unused arguments.

Details

This function is mainly based on the functionality of the spin-plot function once available in XLisp-Stat software https://en.wikipedia.org/wiki/XLispStat, and the adds-on introduced by the Arc software http://www.stat.umn.edu/arc/index.html.

References

Cook R. D., Weisberg S. (1999) Applied Regression Including Computing and Graphics, Wiley, Chapter 8

Author

Luca Scrucca luca.scrucca@unipg.it

Examples

if (FALSE) {
x1 <- rnorm(100)
x2 <- rnorm(100)
y  <- 2*x1 + x2^2 + 0.5*rnorm(100)
spinplot(x1, y, x2)
spinplot(x1, y, x2, scaling = "aaa")
spinplot(x1, y, x2, rem.lin.trend = "TRUE")
spinplot(x1, y, x2, fit.smooth = TRUE)
spinplot(x1, y, x2, fit.ols = TRUE)

x <- iris[,1:3]
y <- iris[,5]
spinplot(x)
spinplot(x, markby = y)
spinplot(x, markby = y, col.points = c("dodgerblue2", "orange", "green3"))
spinplot(x, markby = y, pch = c(0,3,1), col.points = c("dodgerblue2", "orange", "green3"))

# to save plots use 
# rgl.postscript("plot.pdf", fmt="pdf")
# or
# rgl.snapshot("plot.png")
}