indexing in data frames
Thanks. Yes, I got it to work with loops for small data. I was just hoping, given the size of the data.frame (hundreds of thousands) and the length of the lists (varying up to a few hundred) to avoid that if at all possible. Perhaps I'm expecting some behavior that's not feasible? cheers, jimi
On 09Aug, 2012, at 17:39 , arun wrote:
HI,
In the reply I sent, I forgot to add,
anew<-list()#before,
for(i in 1:length(b1)){
anew[[i]]<-list()
anew[[i]]<-b1[[i]]-c[[i]]
}
A.K.
----- Original Message -----
From: jimi adams <jadams at american.edu>
To: r-help at r-project.org
Cc:
Sent: Thursday, August 9, 2012 4:42 PM
Subject: [R] indexing in data frames
I'm still not fully understanding exactly how R is handling data frames, but am getting closer. Any help with this one will likely go a long way in getting me there. Let's say I have a data frame, let's call it "a". Within that data frame i have two variables, let's call them "b" and "c", where "b" is a single numeric value per observation, while "c" is a LIST of numeric values. What I want to be able to do is perform an operation on each element in "c" by the single element in "b".
So, for example, if I wanted to subtract each element in "c" from the scalar in "b". For example, if i had
a$b
[1] 1988 [2] 1989 ? &
a$c
[[1]] [1] 1985 1982 1984 [[2]] [1] 1988 1980 ? I'm looking for a result of: a$new [[1]] [1] 3 6 4 [[2]] [1] 1 9 ? I've tried a few different things, none of which have the desired result. Any help appreciated. thanks! jimi adams Assistant Professor Department of Sociology American University e: jadams at american.edu w: jimiadams.com
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.