cusp3d: Generate 3D plot of Cusp Catastrophe Model Fit

In cusp: Cusp-Catastrophe Model Fitting Using Maximum Likelihood

Generate 3D plot of Cusp Catastrophe Model Fit

Description

This function generates a 3D display of the fit (object) of a cusp model.

Usage

cusp3d(y, alpha = if (!missing(y) && is.list(y)) y$lin[, "alpha"],
    beta = if (!missing(y) && is.list(y)) y$lin[, "beta"], w = 0.03,
    theta = 170, phi = 35, B = 4, Y = 3, Yfloor = -15,
    np = 180, n.surface = 30, surface.plot = TRUE,
    surf.alpha = 0.75, surf.gamma = 1.5, surf.chroma = 35, surf.hue = 240,
    surf.ltheta = 0, surf.lphi = 45, ...)

Arguments

y	object returned by cusp or a vector of observed state values
alpha	vector of normal/symmetry factor values corresponding to the state values in y
beta	vector of bifurcation/splitting factor values corresponding to the state values in y
w	number that specifies the size of the data points plotted on the cusp surface
theta, phi	Angles defining the viewing direction: theta gives the azimuthal direction, and phi the colatitude.
B	range of the splitting factor axis
Y	range of the state variable axis
Yfloor	location on state variable axis where the control surface is plotted
np	factor that determines the fineness of the drawing
n.surface	factor that determines the fineness of the rendered surface
surface.plot	plot the surface?
surf.alpha	transparency level of rendered surface
surf.gamma	factor that determines the shading of surface facets (surf.gamma<1 diminishes shading, surf.gamma>1 exaggerates shading)
surf.chroma, surf.hue	chroma and hue of surface color (see hcl)
surf.ltheta, surf.lphi	the surface is shaded as though it was being illuminated from the direction specified by azimuth surf.ltheta and colatitude surf.lphi
...	named parameters that are passed to persp

Details

This function is experimental.

Value

cusp3d returns the viewing transformation matrix, say VT, a 4 x 4 matrix suitable for projecting 3D coordinates (x,y,z) into the 2D plane using homogeneous 4D coordinates (x,y,z,t). It can be used to superimpose additional graphical elements on the 3D plot, by lines() or points(), using the simple function trans3d().

Note

Currently still somewhat buggy.

Author(s)

Raoul Grasman

References

See cusp-package

See Also

persp, plot.cusp, cusp3d.surface

Examples

set.seed(123)
x1 = runif(150)
x2 = runif(150)
z = Vectorize(rcusp)(1, 4*x1-2, 4*x2-1)
data <- data.frame(x1, x2, z)
fit <- cusp(y ~ z, alpha ~ x1+x2, beta ~ x1+x2, data)

cusp3d(fit)

cusp documentation built on Sept. 11, 2024, 7:05 p.m.