BNPdensity (version 0.7.8)

gsYZstar: Resampling Ystar and Zstar function

Description

This function resamples the distinct pairs (Y,Z)star in the fully nonparametric model.

Usage

gsYZstar(ystar, zstar, nstar, rstar, idx, x, delta, distr.k, distr.py0, mu.py0, sigma.py0, distr.pz0, mu.pz0, sigma.pz0)

Details

For internal use.

Examples

## The function is currently defined as
function (ystar, zstar, nstar, rstar, idx, x, delta, distr.k, 
    distr.py0, mu.py0, sigma.py0, distr.pz0, mu.pz0, sigma.pz0) 
{
    for (j in seq(rstar)) {
        id <- which(!is.na(match(idx, j)))
        xj <- x[id]
        xbar <- sum(xj)/nstar[j]
        y2star <- rk(1, distr = distr.k, mu = xbar, sigma = 1/sqrt(nstar[j]))
        f.ratio <- rfystar(y2star, ystar[j], xj, distr = distr.k, sigma.k = zstar[j], 
            distr.p0 = distr.py0, mu.p0 = mu.py0, sigma.p0 = sigma.py0)
        k.ratioNum <- dk(ystar[j], distr = distr.k, mu = xbar, 
            sigma = 1/sqrt(nstar[j]))
        k.ratioDen <- dk(y2star, distr = distr.k, mu = xbar, 
            sigma = 1/sqrt(nstar[j]))
        k.ratio <- k.ratioNum/k.ratioDen
        q2 <- min(1, f.ratio * k.ratio)
        if (runif(1) <= q2) 
            ystar[j] <- y2star
        z2star <- rk(1, distr = distr.pz0, mu = zstar[j], sigma = zstar[j]/sqrt(delta))
        f.ratio <- rfzstar(ystar[j], xj, distr = distr.k, sigma.k = z2star, 
	      sigma.k2 = zstar[j], distr.p0 = distr.pz0, mu.p0 = mu.pz0, 
	      sigma.p0 = sigma.pz0)
        k.ratioNum <- dk(zstar[j], distr = distr.pz0, mu = z2star, 
            sigma = z2star/sqrt(delta))
        k.ratioDen <- dk(z2star, distr = distr.pz0, mu = zstar[j], 
            sigma = zstar[j]/sqrt(delta))
        k.ratio <- k.ratioNum/k.ratioDen
        q3 <- min(1, f.ratio * k.ratio)
        if (runif(1) <= q3) 
            zstar[j] <- z2star
    }
    return(list(ystar = ystar, zstar = zstar))
  }