Research on generalization for grey forecasting model

Based on trigonometric function transformation cos x , a new method for enhancing smooth degree of the standardized discrete data sequence is put forward. It is proved that the smooth degree of the standardized discrete data sequence by using this transformation can be enhanced Moreover, the GM(1,1) model precision based on the transformation is better than the model precision based on logarithmic function transformation and power function transformation. At last, the method is used to build model of total residence number in Shanghai, the precision of the model is up to 98.5%, the practical application shows the effectiveness of the proposed approach.