[R] ddply (or other suitable solution) question

[Andras Farkas]

Dear All,

I have data frame:
set.seed(123.456)
df <-data.frame(ID=c(1,1,2,2,2,3,3,3,3,4,4,5,5),
                read=c(1,1,0,1,1,1,0,0,0,1,0,0,0),
                int=c(1,1,0,0,0,1,1,0,0,1,1,1,1),
                z=rnorm(13,1,5),
                y=rnorm(13,1,5))

what I would like to achieve (as best as I see it now) is to create multiple lists (and lists within lists using the data in df) that would be based on the groups in the ID column ("top level of list") and "join together" each line item within the group followed by the next line item ("bottom level list"), so would look like this for 

[[ID=1]]
[[1]][[1]]
  ID read int        z        y
  1    1   1 5.188935 5.107905
  1    1   1 1.766866 4.443201
[[ID=2]]
[[2]][[1]]  ID read int         z         y
  2    0   0 -4.690685 3.7695883
  2    1   0  7.269075 0.6904414[[ID=2]]
[[2]][[2]]  ID read int        z          y
  2    1   0 7.269075  0.6904414
  2    1   0 3.132321 -0.5298133[[ID=3]]
[[3]][[1]]  ID read int          z         y
  3    1   1 -0.4753574 -0.902355
  3    0   1  5.4756283 -2.473535
[[ID=3]]
[[3]][[2]]
  3    0   1 5.475628 -2.47353489
  3    0   0 5.390667 -0.03958639


hoping example clear enough... all our help is appreciated,

thanks,



Andras