The discussions of class ratio for AGO algorithm in grey theory

In the grey theory, the class ratio plays a very important role in deciding the accuracy of a prediction model. The authors first review some of the previous research outcomes of class ratio. Second, we not only present a sufficient condition for the convergence of the AGO algorithm (Accumulated Generating Operation Algorithm), which was derived by J.L. Deng (1989), and the necessary condition for the convergence of the AGO algorithm, which was derived by K.L. Wen (2000), but also point out oversights. Finally, we achieve the task of establishing a necessary and sufficient condition for the class ratio to assure the convergence of the AGO algorithm in the analysis field of the GM (1, 1) model.