An Approach of the Grey Modeling Based on Cotangent Function Transformation

In this paper, the method of trigonometric-power function transformation against modeling standardized data is put forward. It has been proved that the smooth degree of data sequence can be improved. This function transformation can greatly improve the smooth degree more than logarithmic function transformation and power function transformation. So the method can widen the range of application of grey modeling. At last, the practical result shows the effectiveness of the proposed approach.