However, the GM (1, 1) Model requires high stationary of the original data and concave data lines trend which has big gray plane.

但是，GM(1,1)模型对于原始数列的平稳性要求较高、数列连线趋势只能为内凹型、灰平面较大。

youdao

However, the GM (1, 1) Model requires high stationary of the original data and concave data lines trend which has big gray plane.

但是，GM(1,1)模型对于原始数列的平稳性要求较高、数列连线趋势只能为内凹型、灰平面较大。

youdao