How do I subset my data.frame by field type (e.g., numeric, character)?

2
votes

I'd like to be able to subset my data.frame, DATA, into numeric fields and factor-type fields. My goal is to write generalized scripts to summarize my data, however, certain functions, such as hist or quantile, are not appropriate for non-numeric data. And it would make more sense to run table on the factor-type fields.

I tried using 

types <- apply( DATA, 2, typeof)

to create a list of types for each field which I could then subset DATA by. However, this only caused errors. I'm sure there is a simply way of doing this but I've done a lot of searching and can't come up with anything.

Thanks.

1
r
Have you tried lapply(data,class)? – diliop
Was going to write that as an answer but perhaps you should? – IRTFM
See this post: stackoverflow.com/questions/3571909/… – Greg
Thanks, diliop. I think that's just what I needed. – bnjmn
Never use apply to iterate over data.frame columns! apply convert data.frame to matrix in first step. It will totally mess your data. – Marek

1 Answers

8
votes

[Since it worked, I'm posting my comment as an answer to this:]

Try lapply(DATA,class)