[R] Problems with rlm

[Ed Hagen]

Dear all,

When calling rlm with the following data, I get an error.  (R v.1.8.1, 
WinXP Pro 2002 with service pack 1.)

> d <- na.omit(data.frame(CPRATIO, HEIGHTZ, FAMILYID))
> c <- tapply(d$CPRATIO, d$FAMILYID, mean)
> h <- tapply(d$HEIGHTZ, d$FAMILYID, mean)
> c
         1         2         3         6         7         9        10
       11
  6.000000  2.500000  3.250000  4.000000  2.333333  2.400000  2.750000
2.000000
        12        13        14        15        16        18        21
       22
  4.000000  5.000000  4.000000  7.000000  4.500000  3.500000  4.000000
5.000000
        23        25        30        31        35        39        40
       44
  6.000000  3.000000  9.000000 10.000000  8.000000 10.000000  4.000000
6.000000
        45        47        50
  4.500000  5.500000  5.000000
> h
          1          2          3          6          7          9
    10
-2.7916667 -1.0246838 -2.0681170 -1.3256766 -3.1122708 -2.1444948
-2.5806538
         11         12         13         14         15         16
    18
-0.6791551 -0.1278583 -3.7737900 -3.3077561 -2.4615233 -3.4016225
-2.2484673
         21         22         23         25         30         31
    35
-0.8938528 -2.2521325 -2.3461999 -2.1405470 -2.7657994 -3.3588822
-2.8144453
         39         40         44         45         47         50
-3.8521439 -2.1882352 -1.7531826 -3.6464482 -2.2158240 -2.7162693
> out <- rlm(h ~ c)
Error in model.matrix.default(mt, mf, contrasts) :
         cannot allocate vector of length 1077237505


If I make the same rlm call a second or third time, R usually crashes.

Any help or suggestions would be greatly appreciated.  These commands
were run after a much larger script had seemingly run successfully. But,
I had no problem calling, e.g., rlm(HEIGHTZ ~ CPRATIO), after the same
script had run.  Although I have made some minor changes in the script, 
I also didn't have this problem when using R 1.7.

Many thanks in advance,

Ed.


-- 
Edward H. Hagen                  Institute for Theoretical Biology
phone: +49/30 2093-8649             Humboldt-Universität zu Berlin
fax:   +49/30 2093-8801                         Invalidenstraße 43
http://itb.biologie.hu-berlin.de/~hagen      10115 Berlin, Germany