Re: [R] shapes in rgl

From: Duncan Golicher <dgoliche_at_sclc.ecosur.mx>
Date: Wed 24 May 2006 - 07:00:29 EST

Thanks so much Greg. I was thinking along similar lines but just couldn't see how to do it. Great trick, just what I needed. They didn't have to be solid, in fact these are potentially more pine like. Now, I wonder what other shapes can be made this way.....

Duncan

Greg Snow wrote:

>Try this function (and modify it to your hearts content):
>
>rgl.cones <- function(x,y,z,h=1,r=0.25, n=36, ...){
>
> r <- rep(r, length.out=length(x))
> h <- rep(h, length.out=length(x))
>
> step <- 2*pi/n
> for (i in seq(along=x)){
> for (j in seq(0, 2*pi-step, length=n)){
> tmp.x <- x[i] + c(0, cos(j)*r[i], cos(j+step)*r[i])
> tmp.z <- z[i] + c(0, sin(j)*r[i], sin(j+step)*r[i])
> tmp.y <- y[i] + h[i]/2*c(1,-1,-1)
>
> rgl.triangles(tmp.x,tmp.y,tmp.z,...)
> }
> }
>}
>
>Hope this helps,
>
>
>

-- 
Dr Duncan Golicher
Ecologia y Sistematica Terrestre
Conservación de la Biodiversidad
El Colegio de la Frontera Sur
San Cristobal de Las Casas, 
Chiapas, Mexico

Email: dgoliche@sclc.ecosur.mx 

Tel: 967 674 9000 ext 1310
Fax: 967 678 2322
Celular: 044 9671041021

United Kingdom Skypein; 020 7870 6251
Skype name: duncangolicher 
Download Skype from http://www.skype.com

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Received on Wed May 24 10:28:01 2006

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