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Orange trees

by Hans Julius Skaug — last modified Mar 31, 2010 07:10 PM
Simple growth curve example with individual effects (random effects) from Pinheiro & Bates (2000)
A growth curve model fitted to the "orange tree" data by Pinheiro & Bates (2000, Ch.8.2) as an illustration of the R (S-Plus) routine nlme(). The logistic growth curve is given as

 

y = f1 /(1 + exp[-(t-f2)/f3]) ] + e,

 

where y is the response and t is the age of the tree. The regression parameters to be estimated are: f1, f2 and f3, and e is the residual error term. A random effect u is added to the parameter f1.

 

Details

 

orange.pdf

 

 

Files

See "Navigation" box to the left.

  • .tpl:  Model file
  • .dat: Data file
  • .pin: Starting values for the numerical optimizer
  • .par: Result file (what you get when you compile and run your model)

 

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