Grey Model (GM): Mathematical Modeling Using Differential Equations from Grey Theory
GM stands for Grey Model, which refers to the differential equation-based model within Grey Theory—G representing Grey and M representing Model. GM(1, N) denotes a first-order differential equation model involving N variables, while GM(1, 1) is a first-order single-variable version. The model is implemented using discrete data sequences and matrix calculations to approximate derivative-based relationships.