qrjoint (version 2.0-9)

chull.center: Fast Interior Point Center of Multivariate Data

Description

Calculates an interior point by averaging a small number of near-extreme points of the cloud.

Usage

chull.center(x, maxEPts = ncol(x) + 1, plot = FALSE)

Value

Returns an interior point of the data cloud. The positions of the near extreme points are returned as the attribute "EPts".

Arguments

x

a matrix giving the data cloud.

maxEPts

integer giving the maximum number of (near)-extreme points to be used in averaging. Default is ncol(x)+1.

plot

logical indicating whether a pairwise scatter plot should be made

Details

Near extreme points are found in a space-filling manner by adding points with minimum residual conditional variance given points already included under a smooth GP specification. See Yang and Tokdar (2015), Section B.1. for more details.

Examples

p <- 9
n <- 200
u <- runif(n)
require(splines)
x <- bs(u, df = p)
chull.center(x, plot = TRUE)