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\name{trans3D}
\alias{trans3D}
\title{
Transformation of 3D elements
}
\description{
\code{trans3D} is the \code{plot3D} equivalent of \link{trans3d}, that projects
3-D elements to 2 dimensions.
}
\usage{
trans3D (x, y, z, pmat)
}
\arguments{
\item{x, y, z }{Vectors, matrices, arrays, with x, y and z-values.
}
\item{pmat }{A 4 x 4 viewing transformation matrix, suitable for projecting
the 3D coordinates (x,y,z) into the 2D plane using homogeneous
4D coordinates (x,y,z,t); such matrices are returned by any of the 3-D
plotting functions from package \code{plot3D} and by \link{persp}().
}
}
\value{
A list with two components:
\item{x, y }{the projected 2-D coordinates of the 3-D input \code{x, y, z}}
In contrast to \link{trans3d}, \code{trans3D} the returned values x and y
will be of the same class and dimensions as the input x and y.
If inputted \code{x, y, z} are matrices or arrays, so will the projected
coordinates be.
}
\seealso{
\link{scatter3D}, \link{slice3D}, \link{surf3D}.
}
\author{Karline Soetaert <karline.soetaert@nioz.nl>}
\examples{
## ========================================================================
## 3-D mesh
## ========================================================================
x <- y <- z <- c(-1 , 0, 1)
# plot a 3-D mesh
(M <- mesh(x, y, z))
# plot result
pmat <- scatter3D(M$x, M$y, M$z, pch = "+", cex = 3, colkey = FALSE)
# add line
XY <- trans3D(x = c(-1, 1), y = c(-1, 1), z = c(-1, 1), pmat = pmat)
lines(XY, lwd = 2, col = "blue")
## ========================================================================
## Example 2
## ========================================================================
pmat <- perspbox (z = diag(2))
XY <- trans3D(x = runif(30), y = runif(30), z = runif(30), pmat = pmat)
polygon(XY, col = "darkblue")
}
\keyword{ hplot }
|
