public double[] estimateGlobalLM(){
		double[] lm = new double[getLMFeatureSize()];
		double sum = 0;
		for(_User u: m_users){
			for(_Review r: u.getReviews()){
				for(_SparseFeature fv: r.getLMSparse()){
					lm[fv.getIndex()] += fv.getValue();
					sum += fv.getValue();
				}
			}
		}
		for(int i=0; i<lm.length; i++){
				lm[i] /= sum;
				if(lm[i] == 0)
					lm[i] = 0.0001;
		}
			return lm;
	}