[R] simple question on picking out some rows of a matrix/data frame
spencer.graves at pdf.com
Tue Feb 10 01:15:41 CET 2004
One alternative that I use is illustrated in the following examples:
> DF[DF$x==DF$y, ]
x y z
1 -1 -1 a
4 1 1 d
> sel <- (DF$x != DF$y)
x y z
2 1 -1 b
3 -1 1 c
hope this help.
Douglas Bates wrote:
>"subset" will do the selection. If you really want a matrix for the
>result you will need to coerce it using "as.matrix".
>Roger Levy <rog at stanford.edu> writes:
>>I have a simple question about matrix/data frame manipulation. I have
>>a data frame that looks a something like this
>> X Y Z
>> 1 0 "apples"
>> -1 -1 "oranges"
>> 0 -1 "bananas"
>>and I'd like to pull out all the rows for which X and Y are (un)equal
>>into a submatrix.
>>How can I do that?
>R-help at stat.math.ethz.ch mailing list
>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
More information about the R-help