package statalign.mcmc;
import org.apache.commons.math3.util.FastMath;
import statalign.utils.NormalDistribution;
public class LogNormalPrior implements PriorDistribution<Double> {
private NormalDistribution n;
private double mean;
private double sd;
public LogNormalPrior(double a, double b) {
mean = a;
sd = b;
n = new NormalDistribution(mean,sd);
}
public double logDensity(Double x) {
return Math.log(n.density(FastMath.log(x)));
}
public double logDensityUnnormalised(Double x) {
return -Math.pow((FastMath.log(x)-mean)/sd, 2)/2 - FastMath.log(sd);
}
}