Hi there,
thanks for the reply. I was expecting what Tony posted. By the way I got the format for my question out of Introduction to R. So I expected it to work as in the text, but it turns out ....
my "list" somehow was not a vector:
> list[1]
[1] PERH0125
44 Levels: PERH0015 PERH0019 PERH0023 PERH0029 PERH0037 PERH0045 PERH0053 PERH0075 ... PERH0360
I did the following:
> list2 = as.vector(list)
> list2
[1] "PERH0125" "PERH0315" "PERH0161" "PERH0181" "PERH0229" "PERH0223" "PERH0243" "PERH0269"
<snip>
I am not sure what format list was in (looks like factor), but I turned it into a vector and it worked as expected. I have to go back and see how I created list in the first place.
originally I took a row from a data frame, removed NA values, then sorted it into an order that I wanted (using 'order') .... so I don't know when it turned into something that looked like factor. Any ?
Peter
At 03:46 PM 7/29/2004, Sundar Dorai-Raj wrote:
Sundar Dorai-Raj wrote:
Peter Wilkinson wrote:
This seems like such a trivial thing to do:
given a data.frame DF and variables w,v, x,y,z I can do
DF["x"] or DF[c("x","y")]
if I create a vector, mylist = c("x",y")
then I do DF[mylist]
I am not getting x and y, I get something else.
what is the correct way to subset a data.frame by columns using a vector, as if I were doing DF["x","y"]?
Peter
______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
You want DF[, mylist]. DF[mylist] returns a list. You may want to look at "An Introduction to R", which covers this topic.
Sorry, typed too quickly.
DF[mylist] and DF[, mylist] are the same if mylist is a vector with more than one element.
After re-reading your post, I'm not quite sure what you are expecting. Sorry for any confusion....
--sundar
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
