ell3d is a convenience wrapper for ellipsoid
specialized for class "gell" objects. It plots an
ellipsoid in the current rgl window.
Usage
ell3d(x, ...)
# Default S3 method
ell3d(x, shape, radius = 1, segments = 40, shade = TRUE, wire = FALSE, ...)
# S3 method for class 'gell'
ell3d(
x,
length = 10,
sides = 30,
segments = 40,
shade = TRUE,
wire = FALSE,
...
)Arguments
- x
A vector of length 3 giving the center of the ellipsoid for the default method, or a class
"gell"object for the gell method.- ...
Other arguments, passed to
ellipsoid- shape
A 3 x 3 symmetric matrix giving the shape of the ellipsoid.
- radius
radius of the ellipsoid
- segments
number of segments in each direction in calculating the
mesh3dobject- shade
Logical. Whether the 3D ellipsoid should be shaded
- wire
Logical. Whether the 3D ellipsoid should be rendered with its wire frame
- length
For unbounded, (infinite) ellipsoids, the length to display for infinite dimensions
- sides
For unbounded, cylindrical ellipsoids, the number of sides for the elliptical cross sections
Value
Returns the result of the call to ellipsoid
Examples
# a proper ellipsoid, and its inverse
c1 <- c(0,0,0)
C1 <- matrix(c(6, 2, 1,
2, 3, 2,
1, 2, 2), 3,3)
open3d()
zell1 <- gell(center=c1, Sigma=C1)
E1 <- ell3d(zell1, col="blue", alpha=0.1)
# inverse of C1
E1I <- ell3d(dual(zell1), col="blue", alpha=0.1, wire=TRUE)
#open3d() ## to see this in a new window
# a singular ellipsoid and its inverse
c2 <- c1
C2 <- matrix(c(6, 2, 0,
2, 3, 0,
0, 0, 0), 3,3)
E2 <- ell3d( zell2 <-gell( center = c2, Sigma = C2),
col = 'red', alpha = 0.25, wire = TRUE)
E2I <- ell3d( dual(gell( center = c2, Sigma = C2)),
length=3, col = 'red', alpha = 0.25, wire = TRUE )
# signatures
signature(zell1)
#> pos zero inf
#> 3 0 0
signature(zell2)
#> pos zero inf
#> 2 1 0