x - rle(id)
cumsum(x$lengths) - (x$lengths - 1)
cumsum(x$lengths)
Alan
On Tue, May 25, 2010 at 10:00 PM, Gabor Grothendieck
ggrothendi...@gmail.com wrote:
This assumes that for a particular id they all occur together in a run:
cbind(start = which(!duplicated(id)), end = which(!duplicated(id,
Hallo!
I have a vector of ID's like so,
id - c(1,2,2,3,3,3,4,5,5)
I would like to create a [start,stop] pair of vectors that index the first
and last observation per ID.
For the ID list above, it would look like
1 1
2 3
4 6
7 7
8 9
I haven't worked with indexes/data manipulation much in R, so
Of Robin Jeffries
Sent: Wednesday, 26 May 2010 4:15 p.m.
To: r-help@r-project.org
Subject: [R] Counting indexes
Hallo!
I have a vector of ID's like so,
id - c(1,2,2,3,3,3,4,5,5)
I would like to create a [start,stop] pair of vectors that index the
first
and last observation per ID
Robin Jeffries wrote:
Hallo!
I have a vector of ID's like so,
id - c(1,2,2,3,3,3,4,5,5)
I would like to create a [start,stop] pair of vectors that index the first
and last observation per ID.
For the ID list above, it would look like
1 1
2 3
4 6
7 7
8 9
which(!duplicated(id))
[1] 1 2 4 7 8
Awesome! Thanks:)
On Tue, May 25, 2010 at 9:40 PM, Erik Iverson er...@ccbr.umn.edu wrote:
Robin Jeffries wrote:
Hallo!
I have a vector of ID's like so,
id - c(1,2,2,3,3,3,4,5,5)
I would like to create a [start,stop] pair of vectors that index the first
and last observation per ID.
This assumes that for a particular id they all occur together in a run:
cbind(start = which(!duplicated(id)), end = which(!duplicated(id, fromLast =
TRUE)))
start end
[1,] 1 1
[2,] 2 3
[3,] 4 6
[4,] 7 7
[5,] 8 9
On Wed, May 26, 2010 at 12:14 AM, Robin
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