Question

I have a question about the extraction of multiple values from a data.frame in R.

I have a data.frame that looks like this:

              language ID                  value
1             Dutch   A1                  6
2             Dutch   A2                  6
3             Dutch   A3                  6
4             Dutch   A4                  6
5             Dutch   A5                  6
6        Portuguese   A1                  6
7        Portuguese   A2                  1
8        Portuguese   A3                  6
9        Portuguese   A4                 10
10       Portuguese   A5                  6
11            Irish   A4                  6
12            Irish   A1                  1
13            Irish   A2                  6
14            Irish   A3                  6 
15            Irish   A5                  6

I want to be able to select any set of columns which have a certain ID. For instance, I want to be able to select the columns which have ‘Dutch’ as their language, and ‘A1’, ‘A2’, and ‘A3’ and place them in a new data.frame. How can I do that?

Many thanks!

Answer 1

Use subset to subset your data:

subset(dfr, language=="Dutch" & ID %in% c("A1","A2","A3"))