CODEWITHSUNDEEP
rsortingdataframe
jon
jon

Reputation: 11386

order another data frame by row preserving the order in r

I have got two data frames. 

daf <- data.frame (A = 1:10, J = 1:10, E = 11:20, D = 21:30, C= 41:50, B = 61:70, L = 3:12)
 df2 <- data.frame (nam = c("A", "B", "C", "E", "D"), sn = 1:5)


    > df2
  nam sn
1   A  1
2   B  2
3   C  3
4   E  4
5   D  5

> daf
    A  J  E  D  C  B  L
1   1  1 11 21 41 61  3
2   2  2 12 22 42 62  4
3   3  3 13 23 43 63  5
4   4  4 14 24 44 64  6
5   5  5 15 25 45 65  7
6   6  6 16 26 46 66  8
7   7  7 17 27 47 67  9
8   8  8 18 28 48 68 10
9   9  9 19 29 49 69 11
10 10 10 20 30 50 70 12

I would like to pickup only variable names listed in nam of df2. I would like to preserve the order of df2. 

daf.n <- colnames(daf)
df2.n <- df2[,1]
daf[df2.n%in%colnames(daf),] 
    A  J  E  D  C  B  L
1   1  1 11 21 41 61  3
2   2  2 12 22 42 62  4
3   3  3 13 23 43 63  5
4   4  4 14 24 44 64  6
5   5  5 15 25 45 65  7
6   6  6 16 26 46 66  8
7   7  7 17 27 47 67  9
8   8  8 18 28 48 68 10
9   9  9 19 29 49 69 11
10 10 10 20 30 50 70 12

Above do the first job but do not order the columns in order they are arranged in df2 column nam. Any idea ?

Upvotes: 1

Views: 54

Answers (1)

Karsten W.
Karsten W.

Reputation: 18500

Not need for %in%:

 daf <- data.frame (A = 1:10, J = 1:10, E = 11:20, D = 21:30, C= 41:50, B = 61:70, L = 3:12)
 df2 <- data.frame (nam = c("A", "B", "C", "E", "D"), sn = 1:5)
 daf[,as.character(df2$nam)]

Note that your example data.frames are slightly altered here.

Upvotes: 2

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