化肥需要量灰色预测模型参数的四阶求法

4 Order Method of Calculating the Parameters of Grey Forecasting Model to Requirement of Fertilizer

针对文［１］化肥需要量灰色预测模型误差较大且预测结果与定性分析矛盾的问题，本文提出和应用了确定Ｖｅｒｈｕｌｓｔ模型参数的四阶方法，并重新合理配置建模数据而得一预测模型．计算表明新模型与实际值的拟合精度提高近十倍，而且预测结果与定性分析完全一致．

In this paper, we point that the error of Grey forecasting model in paper is very big and the forecasting result conflicts with the property analysis. Furthermore, we put parameters of Verhulst model, adjust modeling data reasonably and get finally a new predicting model. The result of calculation indicate that the precision of the new model is about 10 times higher than one of old model and now the forecasting result is in conformity with the property analysis.