Gaussian function formula: f(x)=d*ad. Gaussian function is named after the great mathematician Johann Carl Friedrich Gauss. Gaussian function is widely used in natural science, social science, mathematics and engineering.

The definition of function is usually divided into traditional definition and modern definition. The two definitions of functions are essentially the same, but the starting point of describing concepts is different. The traditional definition is from the perspective of movement change, and the modern definition is from the perspective of set and mapping.