[R] residual lag scatter plot

[Jean Eid]

Dear all,

I am looking for a function that  can scatter  plot the residuals obtained
from a longitudinal model i.e. plot  e_{i,j} e_{i,k} for
all j< k = 1,..n ( I have 7 observations for each subject). something
similar to the pairs() function.
I can do it the long way by constructing a residual matrix and use pairs.
However, I am wondering if there is a builty in function to do this.