From: Tom La Bone <booboo_at_gforcecable.com>

Date: Fri, 25 Jul 2008 09:20:39 -0700 (PDT)

>> 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')
*

Date: Fri, 25 Jul 2008 09:20:39 -0700 (PDT)

On further experimentation I find that "points" (via points3d) serve my purpose well (instead of the much prettier but more troublesome spheres). The default "point" appears to be a square. Is there a way to make it a circle?

Tom

Duncan Murdoch-2 wrote:

> > On 7/25/2008 11:01 AM, Tom La Bone wrote:

>> After looking around a bit more I found the example I was looking for --

> > > I think you're seeing the effect of the inaccurate bounding box > calculation described in ?spheres3d. The problem is that you're asking > for a sphere, but your axes are on wildly different scales. The > bounding box calculation for that situation fails. > > You can work around this by telling rgl to ignore the extent of the > spheres (via par3d(ignoreExtent=TRUE)), and plot some points in the > corners of the bounding box you really want. Set their alpha to 0 and > they'll be invisible. > > Some day I'll probably fix this, but it's likely to be a while. > > Duncan Murdoch > > ______________________________________________ > R-help_at_r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > >

-- View this message in context: http://www.nabble.com/Tutorial-on-rgl-Graphics-tp18649114p18655047.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help_at_r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.Received on Fri 25 Jul 2008 - 16:24:23 GMT

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