BRISC_variogram.ci {BRISC}

Function for plotting estimated Variogram and confidence region

Description

The function BRISC_variogram.ci plots estimated Variogram and associated confience region. BRISC_variogram.ci uses the parameter estimates from BRISC_estimation and associated confidence interval from BRISC_bootstrap.

Usage

BRISC_variogram.ci(BRISC_Out, confidence_est,
                   plot.variogram = FALSE)

Arguments

BRISC_Out

an object of class BRISC_Out, obtained as an output of
BRISC_estimation.

confidence_est

bootstrp sample of the Theta parameters, obtained from BRISC_bootstrap.

plot.variogram

if TRUE, plots the variogram and the associated confidence region. Default is FALSE.

Value

A list comprising of the following:

variogram

variogram and associated confidence region corresponding to lag ranging from 0 to 20, evaluated at 0.01 frequency.

Plot

plots the Variogram and associated confidence region with legends.

Author(s)

Arkajyoti Saha [e-mail],
Abhirup Datta [e-mail]

Examples

rmvn <- function(n, mu = 0, V = matrix(1)){
  p <- length(mu)
  if(any(is.na(match(dim(V),p))))
    stop("Dimension not right!")
  D <- chol(V)
  t(matrix(rnorm(n*p), ncol=p)%*%D + rep(mu,rep(n,p)))
}

set.seed(1)
n <- 300
coords <- cbind(runif(n,0,1), runif(n,0,1))

beta <- c(1,5)
x <- cbind(rnorm(n), rnorm(n))

sigma.sq = 1
phi = 5
tau.sq = 0.1

B <- as.matrix(beta)
D <- as.matrix(dist(coords))
R <- exp(-phi*D)
w <- rmvn(1, rep(0,n), sigma.sq*R)

y <- rnorm(n, x%*%B + w, sqrt(tau.sq))

estimation_result <- BRISC_estimation(coords, y, x)
bootstrap_result <- BRISC_bootstrap(estimation_result, n_boot = 10)
varg <- BRISC_variogram.ci(estimation_result,
                           bootstrap_result$boot.Theta,
                           plot.variogram = TRUE)