兴安落叶松材积模型中的异方差研究

为进一步提高兴安落叶松材积模型估计精度,文章选择V=aDbHc为材积模型形式,对模型的异方差性进行了研究。文章分别使用了图示法及戈德菲尔特-夸检验方法证实模型中存在较强的异方差性,并分别以因变量,自变量及模型本身构造权函数,以加权回归估计和普通非线性回归估计方法结果进行对比分析。研究结果表明:加权回归估计优于普通非线性回归估计;在构造的众多权函数中,以权函数1/D2H为最优;并进一步证实不同的模型有不同的最优权函数形式。

Study on heteroscedasticity of Larix gmelini(Rupr.)in volume model

This paper study heteroscedasticity of Larix gmelini(Rupr.)volume model with for improving estimate precision on the model.The heteroscedasticity was affirmed in volume model using cartography and Goldfeld-Quandt test,and weighting function was made from independent variable,attributive variable and model,and weighting regression was a contrast to usual nonlinear regression.Study results show that weighting regression was better with usual nonlinear regression;1/ D2H was had best to so;and it was proved tha...