Dear Devels, I'm not sure if I'm going the right way by mailing to this list. I have two suggestions regarding the persp function from the graphics package: 1. In the documentation of the persp function, it is said, that the "col" argument will ignore transparent colors. However, this is not true, if you use strings as color code - at least it works with HEX-code (eg. : col="#bf000022" would produce a red-colored surface with transparency = 22). 2. It would be helpful if one could add a surface to an existing plot. I simply copied persp and deleted the "plot.new()" line, but I guess there are better ways... Cheers, Christoph [[alternative HTML version deleted]]
On 13-10-08 1:48 AM, Christoph H?ni wrote:> Dear Devels, > > I'm not sure if I'm going the right way by mailing to this list. I have two > suggestions regarding the persp function from the graphics package: > > 1. In the documentation of the persp function, it is said, that the "col" > argument will ignore transparent colors. However, this is not true, if you > use strings as color code - at least it works with HEX-code (eg. : > col="#bf000022" would produce a red-colored surface with transparency = 22).That may be an obsolete limitation. I'll take a look...> > 2. It would be helpful if one could add a surface to an existing plot. I > simply copied persp and deleted the "plot.new()" line, but I guess there > are better ways...That won't work in general. persp() relies in the "painter's algorithm", in which objects at the back are drawn before objects in front of them. If you put two surfaces into the same plot there will be no way to guarantee that. If you want two surfaces in the same plot (or other things in a surface plot), you should probably use persp3d from the rgl package. Duncan Murdoch
On 13-10-08 1:48 AM, Christoph H?ni wrote:> Dear Devels, > > I'm not sure if I'm going the right way by mailing to this list. I have two > suggestions regarding the persp function from the graphics package: > > 1. In the documentation of the persp function, it is said, that the "col" > argument will ignore transparent colors. However, this is not true, if you > use strings as color code - at least it works with HEX-code (eg. : > col="#bf000022" would produce a red-colored surface with transparency = 22).The actual behaviour is that if lighting (controlled by the "shade" argument) is active, transparency is ignored. However, if the first colour is transparent, lighting is turned off, so transparency *will* be used. I'm not sure what the intention was behind the latter behaviour. Duncan Murdoch> > 2. It would be helpful if one could add a surface to an existing plot. I > simply copied persp and deleted the "plot.new()" line, but I guess there > are better ways... > > Cheers, > Christoph > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel >