> From: Bill Simpson <wsimpson at uwinnipeg.ca> > Subject: Re: contour labelling [was "Re: [R] image ()"] > MIME-Version: 1.0 > > > We may be missing the crux here: was it to have a means of > > displaying such surfaces? > > Yes, bang on. I knew of the > existence of the Delaunay code in the R libraries. Yes I want > to make a picture that places a planar facet on each triangle. > The resulting surface looks like the surface of a cut diamond > for example (assuming the cuts give triangular facets). So far > as I know there is no way to display such a 3D plot in R. persp > uses rectangular rather than triangular mesh.Once the trianglation was produced it would be just a minor change in the present "persp" function to plot it. The algorithm I use is to sort the facets by depth and then to plot them, back to front. This works just as well for triangular facets as rectangular ones. If you'd care to define some data structures (or better yet a class) which will hold a desciption of the triangulation, I can have my student tweak the present code to display the structure. Ross -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
On Sat, 5 Dec 1998, Ross Ihaka wrote:> Once the trianglation was produced it would be just a minor change in > the present "persp" function to plot it. The algorithm I use is to > sort the facets by depth and then to plot them, back to front. This > works just as well for triangular facets as rectangular ones.Great!> If you'd care to define some data structures (or better yet a class) > which will hold a desciption of the triangulation, I can have my student > tweak the present code to display the structure.Sorry to be such an idiot but I'm afraid that's beyond me. Should I try to figure out the output of akima, then tell you what I find out? I imagine that would be the input to the triangle version of persp. Thanks very much Ross. Bill -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._