R How to convert column value to list in row of another column

Asked Feb 11 '15 at 14:39

Active Apr 06 '16 at 02:37

Viewed 37 times

I have the following data:

d <- data.table(c = c("ABC", "XYZ", "IJK"), i = c("102", "102", "103"), n = c(100, 100, 1) )
> d
     c   i   n
1: ABC 102 100
2: XYZ 102 100
3: IJK 103   1

and wish to arrive to the result:

res <- data.table(i = c("102", "103"), n = c(100, 1), c = c("ABC, XYZ", "IJK") )
> res
     i   n        c
1: 102 100 ABC, XYZ
2: 103   1      IJK

which transformed the information in column 'c' (the first column) into the values in the third column of res.

How can I do that?

edited Apr 06 '16 at 02:37

Matt Dowle

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asked Feb 11 '15 at 14:39

Timothée HENRY

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`d[,.(c=toString(c)),by=.(i,n)]` – Marat Talipov Feb 11 '15 at 14:49
Instead of `toString` you can also use `list` which could make it easier to go on working with column c: `d[,.(c=list(c)),by=.(i,n)]` – Rentrop Feb 11 '15 at 15:07

R How to convert column value to list in row of another column

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