public Discrete getDiscretePoissonOneToN(int N, double lambda) {
		N = N + 2;
		distribution = new double[N];
		sum = 0.0;
		for(int i = 1; i < N-1; i ++){
			distribution[i] = poisson(lambda, i);
			sum += distribution[i];
		}
		
		for(int i = 1; i < N-1; i ++)
			distribution[i] = distribution[i]/sum;
		
		return new Discrete(distribution);
	}