public Normal(double mu, double sigmaSquared) throws ParameterException {
		if (sigmaSquared <= 0) {
			throw new ParameterException("Normal parameters mu real, sigmaSquared > 0.");
		}
		rand = new Random();
		this.mu = mu;
		this.sigmaSquared = sigmaSquared;
		sigma = Math.sqrt(sigmaSquared);
	}