r - 将随机效应附加到数据

Question

请考虑以下代码：

dt <- sleepstudy
fm <- lmer(Reaction ~ Days + (1|Subject), data=dt)
re <- lme4::ranef(fm)

所以我们有

> head(dt)
  Reaction Days Subject
1 249.5600    0     308
2 258.7047    1     308
3 250.8006    2     308
4 321.4398    3     308
5 356.8519    4     308
6 414.6901    5     308

> head(re[[1]])
    (Intercept)
308   40.787403
309  -77.856603
310  -63.114282
330    4.406841
331   10.217114
332    8.221982

将随机效应附加到数据的最佳方法是什么，最终得到

  Reaction Days Subject    re
1 249.5600    0     308    40.787403
2 258.7047    1     308    40.787403
3 250.8006    2     308    40.787403
4 321.4398    3     308    40.787403
5 356.8519    4     308    40.787403
6 414.6901    5     308    40.787403
etc...

Answer 1

你想用merge..

merge(dt, re, by.x= "Subject", by.y = "row.names" )

你也可以使用match

dt$re <- re[ match(dt$Subject, rownames(re) ) , "(Intercept)" ]
# the "(Intercept)" is whatever your column 
#                                        in re with the random effect is called