Question

Possible Duplicate:
How to sort a dataframe by column(s) in R

Here is the dataset:

odervect <- c("xaf", "c3a", "c3b", "ka101","jk12", "cd101", "kl01v", "klm1")
odervect
[1] "xaf" "c3a"   "c3b"   "ka101" "jk12"  "cd101" "kl01v" "klm1"  

dfd <- data.frame(ka101 = 101:110,c3a = 1:10, kl01v = 301:310, xaf = 11:20,
    c3b = 41:50, cd101 = 61:70)


 dfd 

   ka101 c3a kl01v xaf c3b cd101
1    101   1   301  11  41    61
2    102   2   302  12  42    62
3    103   3   303  13  43    63
4    104   4   304  14  44    64
5    105   5   305  15  45    65
6    106   6   306  16  46    66
7    107   7   307  17  47    67
8    108   8   308  18  48    68
9    109   9   309  19  49    69
10   110  10   310  20  50    70

Desired output:

 dfd1 <- data.frame(xaf = 11:20, c3a = 1:10, c3b = 41:50,ka101 = 101:110, cd101 = 61:70,
     ka101v = 301:310)
    dfd1 
        xaf c3a c3b ka101 cd101 ka101v
1   11   1  41   101    61    301
2   12   2  42   102    62    302
3   13   3  43   103    63    303
4   14   4  44   104    64    304
5   15   5  45   105    65    305
6   16   6  46   106    66    306
7   17   7  47   107    67    307
8   18   8  48   108    68    308
9   19   9  49   109    69    309
10  20  10  50   110    70    310

Please note that not all names in order vector are present in dfd, however only need to sort the matching ones.

Answer 1

How about this? It first uses %in% to select (still in order) the strings in odervect that correspond to column names present in dfd:

cnames <- odervect[odervect %in% names(dfd)]
dfd[cnames]
   xaf c3a c3b ka101 cd101 kl01v
1   11   1  41   101    61   301
2   12   2  42   102    62   302
3   13   3  43   103    63   303
4   14   4  44   104    64   304
5   15   5  45   105    65   305
6   16   6  46   106    66   306
7   17   7  47   107    67   307
8   18   8  48   108    68   308
9   19   9  49   109    69   309
10  20  10  50   110    70   310