After looking around a bit more I found the example I was looking for --
plotlm3d, which I found on the R wiki
http://wiki.r-project.org/rwiki/doku.php?id=graph_gallery:new-graphics
The original author was John Fox, and it was modified by Jose Claudio Faria
and Duncan Murdoch. Below is a simplified version of the function and two
examples. One example was presented as a test of the function and it works
fine. The second example is the plot I want to make and I can't seem to get
the scale on the x and y axes correct. Being unfamiliar with rgl, can
someone provide a hint on how to get the scales right? Thanks for the help.
Tom
plotlm3d <- function (x, y, z,
surface = T,
model = 'z ~ x + y',
simple.axes = T,
box = F,
xlab = deparse(substitute(x)),
ylab = deparse(substitute(y)),
zlab = deparse(substitute(z)),
surface.col = c('blue', 'orange', 'red', 'green',
'magenta', 'cyan', 'yellow',
'gray', 'brown'),
point.col = 'yellow',
grid.col = material3d("color"),
grid = T,
grid.lines = 26,
sphere.factor = 1,
threshold = 0.01)
{
require(rgl)
require(mgcv)
xlab; ylab; zlab
size <- max(c(x,y,z))/100 * sphere.factor
if (size > threshold)
spheres3d(x, y, z, color = point.col, radius = size)
else
points3d(x, y, z, color = point.col)
aspect3d(c(1, 1, 1))
if (surface) {
xvals <- seq(min(x), max(x), length = grid.lines)
yvals <- seq(min(y), max(y), length = grid.lines)
dat <- expand.grid(x = xvals, y = yvals)
for (i in 1:length(model)) {
mod <- lm(formula(model[i]))
zhat <- matrix(predict(mod, newdata = dat), grid.lines, grid.lines)
surface3d(xvals, yvals, zhat, color = surface.col[i], alpha = 0.5, lit
= F)
if (grid)
surface3d(xvals, yvals, zhat, color = grid.col, alpha = 0.5,
lit = F, front = 'lines', back = 'lines') }}
if(simple.axes) {
axes3d(c('x', 'y', 'z'))
title3d(xlab = xlab, ylab = ylab, zlab = zlab)
}
else
decorate3d(xlab = xlab, ylab = ylab, zlab = zlab, box = box)
}
#This is an example of a 3D scatterplot that works fine
x <- c( 274, 180, 375, 205, 86, 265, 98, 330, 195, 53,
430, 372, 236, 157, 370)
y <- c(2450, 3254, 3802, 2838, 2347, 3782, 3008, 2450, 2137, 2560,
4020, 4427, 2660, 2088, 2605)
z <- c( 162, 120, 223, 131, 67, 169, 81, 192, 116, 55,
252, 232, 144, 103, 212)
open3d()
plotlm3d(x, y, z,
surface = T,
model = 'z ~ x + y',
xlab = 'x',
ylab = 'y',
zlab = 'z')
#This is the plot I am trying to make - scales on x and y axes are wrong
x <- c(0.3405,0.1220,0.1028,0.08451,0.05668,0.0345,0.003788,0.002121)
y <- c(0.3460,0.1227,0.1097,0.09666,0.07677,0.06278,0.02168,0.01303)
z <- c(2720,1150,1010,790,482,358,78,35)
open3d()
plotlm3d(x, y, z,
surface = T,
model = 'z ~ x + y - 1',
xlab = 'x',
ylab = 'y',
zlab = 'z')
