Full_Name: Bert Tijhuis Version: 2.8.0 OS: MS-Windows Submission from: (NULL) (217.140.7.52) > xd [1] 0.5 -1.0 0.2 NA -3.0 1.0 2.0 NA 2.0 > sort(xd, index=T)$ix [1] 4 2 3 1 5 6 7 And in my believe it should be 5 2 3 1 6 7 8 4 9 This was function well in R 2.7.2 Good luck,