shape2d: Returns a 2D volume function or 2D probability content...

In denpro: Visualization of Multivariate Functions, Sets, and Data

Description

Calculates a 2D volume function or 2D probability content function from a sequence of shape trees, corresponding to a sequence of level sets of a multivariate function to be visualized. A 2D volume function and 2D probability content function are visualizations of a multivariate density with a 2D function. One joins a series of radius functions or tail probability functions to get a 2D visualization. Radius functions and tail probability functions are 1D functions which visualize the shape of level sets of a multivariate density.

Usage

shape2d(shtseq, gnum = 500, type = "radius", type2 = "slice", 
gnum2 = 1000, ngrid = 30, norma = FALSE, xmax = 10, modelim = 2, 
exmalim = NULL, maxnum = NULL)

Arguments

shtseq	A list of shape trees, made by function "stseq"; the shape trees in the list correspond to a grid of level sets of the function to be visualized
gnum	Number of grid points in the radius function or in the tail probability function (used when one transforms a shape tree to a 1D function)
type	"radius" or "proba"; whether a 2D volume function or 2D probability content function will be calculated
type2	"slice" or "boundary"; whether the 1D functions are slices or level sets of the 2D function. The option "boundary" is not recommended at the moment
gnum2	when type2="boundary", then gnum*gnum is the size of the grid of the 2D function, and "gnum2" is the grid used for transforming shape trees to 1D functions
ngrid	positive integer; one prunes the 1D functions to have "ngrid" level sets
norma	TRUE if one uses dimension normalization for the volumes; then volumes are tranformed to (volume/V)pow(1/d), where V is the volume of the d-dimensional unit ball
xmax	internal
modelim	internal
exmalim	internal
maxnum	internal

Value

A list containing elements x, y, z, whose meaning is the same as in function "persp".

Author(s)

Jussi Klemela

References

Jussi Klemela (2005). Visualization of the spread of multivariate distributions.

See Also

stseq, plotvolu2d

Examples

N<-c(30,30)  
lnum<-20
func<-"gumbel"
marginal<-"normal"
g<-2
ver<-3
support<-c(-ver,ver,-ver,ver)
st<-stseq(N,lnum,func=func,marginal=marginal,g=g,support=support)

gnum<-50 
ngrid=50 
vd<-shape2d(st,gnum=gnum,ngrid=ngrid) 

plotvolu2d(vd)

type<-"proba"
vd3<-shape2d(st,gnum=gnum,type=type,ngrid=ngrid,norma=TRUE)

plotvolu2d(vd3)

denpro documentation built on May 2, 2019, 8:55 a.m.