Fitting Chapman-Richards Models with Fized and Random Coefficients for Dahurian Larch in S-Plus

摘要：

Statistical models in which both fixed and random effects enter nonlinearly are becoming increasingly popular. These models have a wide variety of applications, one of the most common being nonlinear growth data. In this study, tree growth data set from forestry is used for nonlinear mixedeffects analysis. Nonlinear mixed-effects models involve both fixed effects and random effects. The process of model building for nonlinear mixed-effects models is to determine which parameters should be random effects and which should be purely fixed effects, as well as procedures for determining random effects variance-covariance matrices (e.g. diagonal matrices) to reduce the number of the parameters in the model. We also consider procedures for determining covariates to explain interindividual parameter variability. Information criterion statistics are used for comparing different structures of the random effects components. These methods are illustrated using the nonlinear mixedeffects methods in S-Plus software.

关键词： Random Effects Mized Effects Nlme Library Growth

作者: LI Yaoxiang

作者单位: Northeast Forestry University, Harbin, P.R.China, 150040

会议类型: 国际会议

会议名称: 2008年国际应用统计学术研讨会(2008 International Institute of Applied Statistics Studies)

会议地点: 烟台

会议语种:英文

页码: 1-6

在线出版日期: 2008-08-14（万方平台首次上网日期，不代表论文的发表时间）