| % File src/library/grDevices/man/trans3d.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{trans3d} |
| \alias{trans3d} |
| \title{3D to 2D Transformation for Perspective Plots} |
| \description{ |
| Projection of 3-dimensional to 2-dimensional points using a 4x4 |
| viewing transformation matrix. Mainly for adding to |
| perspective plots such as \code{\link{persp}}. |
| } |
| \usage{ |
| trans3d(x, y, z, pmat) |
| } |
| \arguments{ |
| \item{x, y, z}{numeric vectors of equal length, specifying points in |
| 3D space.} |
| \item{pmat}{a \eqn{4 \times 4}{4 x 4} \emph{viewing transformation matrix}, |
| suitable for projecting the 3D coordinates \eqn{(x,y,z)} into the 2D |
| plane using homogeneous 4D coordinates \eqn{(x,y,z,t)}; |
| such matrices are returned by \code{\link{persp}()}.} |
| } |
| \value{ |
| a list with two components |
| \item{x,y}{the projected 2d coordinates of the 3d input \code{(x,y,z)}.} |
| } |
| \seealso{ \code{\link{persp}} } |
| \examples{ |
| %% it would be nice to have an independent example |
| ## See help(persp) {after attaching the 'graphics' package} |
| ## ----------- |
| } |
| \keyword{dplot} |