r - 为什么在尝试对自相关建模时会出现错误，即使完全遵循 Pinheiro 和 Bates (2009) 中的这个示例？

Question

这是 Mixed Effects Models in S and S-Plus 的摘录页238 :




这是我用来重新创建此示例的代码:

library(nlme)
spatDat <- data.frame(x = c(0,0.25,0.5,0.75,1), y = c(0,0.25,0.5,0.50,0.75))
cs1Exp <- corExp(1, form = ~x+y)
cs1Exp <- initialize(cs1Exp, spatDat)

但是当我这样做时，我得到这个错误:

Error in getClass(Class) : 
  c("\"corExp\" is not a defined class", "\"corSpatial\" is not a defined class", "\"corStruct\" is not a defined class")
In addition: Warning message:
In if (!is.na(match(Class, .BasicClasses))) return(newBasic(Class,  :
  the condition has length > 1 and only the first element will be used

为什么我会收到这个错误？

附录

R version 2.13.0 (2011-04-13)
Platform: x86_64-pc-linux-gnu (64-bit)
attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] nlme_3.1-101

loaded via a namespace (and not attached):
[1] grid_2.13.0     lattice_0.19-26

Answer 1

原因是 Initialize 拿资本I在 nlme所以它不会与 initialize 混淆在 base .然后是 Vivi 对 spatdat$y 的评论

这有效:

> library(nlme)
> spatDat <- data.frame(x = c(0,0.25,0.5,0.75,1), y = c(0,0.25,0.50,0.75,1.0))
> cs1Exp <- corExp( 1, form = ~x+y )
> cs1Exp <- Initialize( cs1Exp, spatDat )
> corMatrix( cs1Exp )
          [,1]      [,2]      [,3]      [,4]      [,5]
[1,] 1.0000000 0.7021885 0.4930687 0.3462272 0.2431167
[2,] 0.7021885 1.0000000 0.7021885 0.4930687 0.3462272
[3,] 0.4930687 0.7021885 1.0000000 0.7021885 0.4930687
[4,] 0.3462272 0.4930687 0.7021885 1.0000000 0.7021885
[5,] 0.2431167 0.3462272 0.4930687 0.7021885 1.0000000