Another way is using straightforward indexing:
> x <- cbind(trips=c(1,3,2), y=1:3, z=4:6)
> x
trips y z
[1,] 1 1 4
[2,] 3 2 5
[3,] 2 3 6
> # generate row indices with the appropriate
> # number of repeats
> ii <- rep(seq(len=nrow(x)), x[,1])
[1] 1 2 2 2 3 3
> # use these indices to select data rows
> x[ii, -1]
y z
[1,] 1 4
[2,] 2 5
[3,] 2 5
[4,] 2 5
[5,] 3 6
[6,] 3 6
>
Jorge Ivan Velez wrote:
Hi Marion,
Try this:
set.seed(123)
mydf=data.frame(trips=rpois(10,5), matrix(rnorm(10*5),ncol=5))
mydf
sapply(mydf[,-1],rep,mydf[,1])
HTH,
Jorge
On Wed, May 7, 2008 at 11:41 PM, <[EMAIL PROTECTED]> wrote:
Hi,
I have a data matrix in which there are 1000 rows by 30 columns. The
first
column of each row is a numeric indicating the number of trips taken to a
particular location with location attributes in the following column
entries for
that row.
I want to repeat each row based on the number of trips taken (as indicated
by
the number in the first column)...i.e., if 1,1 indicates 4 trips, I want
to
replicate row 1 four times, and do this for each entry of column 1.
I have played with rep command with little luck. Can anyone help? This is
probably very simple.
Thank you,
mw
Marion Wittmann, Ph.D. candidate
Environmental Science and Management
University of California
Santa Barbara, CA 93106-5131
______________________________________________
R-help@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.
[[alternative HTML version deleted]]
______________________________________________
R-help@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.
______________________________________________
R-help@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.
