On Oct 28, 2011, at 11:26 AM, William Dunlap wrote:
Are you looking for something like the following? ifactor()
is like factor but assumes that x is integral and that levels
should be {1, 2, ..., max(x)} with no gaps.
x <- c(1,3,4,9,1,9,1,5,4,5,2,1,1,1,6)
ifactor <- function(x, levels=seq_len(max(0, x, na.rm=TRUE)))
factor(x, levels=levels)
with(rle(x), table(ifactor(values), ifactor(lengths)))
1 2 3
1 3 0 1
2 1 0 0
3 1 0 0
4 2 0 0
5 2 0 0
6 1 0 0
7 0 0 0
8 0 0 0
9 2 0 0
Also note that tbl["2","3"] does not mean the same as tbl[2,3],
although if you use the ifactor function as above they will refer
to the same element.
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
I answered earlier in a posting that did not get threaded properly in
my mailer and this is a précis:
> xtbl <- with(rle(x), table(values, lengths))
> xtbl["1", which( as.numeric( attr(xtbl, "dimnames")$lengths) >=2 )]
3 5
1 1
Since character-numeric comparisons appear to get properly coerced the
as numeric may not be necessary:
> xtbl["1", which( attr(xtbl, "dimnames")$lengths >=2 )]
3 5
1 1
--
David.
-----Original Message-----
From: [email protected] [mailto:[email protected]
] On Behalf Of Samir Benzerfa
Sent: Friday, October 28, 2011 12:35 AM
To: 'David Winsemius'; 'Duncan Murdoch'
Cc: [email protected]
Subject: Re: [R] question R regarding consecutive numbers
In the general case, there is still a gap in your solution
>sum( tbl["1",
2:ncol(tbl)] ). This solution refers to a specific column number
(here:
column number 2) and not to the actual length of the run, doesn't
it? That
is, in this simple example the column number 2 actually corresponds
to the
length "2", but this must not be the case in general. For instance
if there
is no run of length "2" but only of length "1" and "3", the column
number 2
will refer to length "3" (try it with the new vector below). I
realized this
problem when applying your solution to a much more extended vector.
So, the
problem is that I would have to check manually whether the column
number
really corresponds to the length of runs. A possible solution would
be to
force R to show all the lengths from 1:ncol even if there is no run
of some
lengths in-between and just fill the whole column with zero's.
x=c(1,3,4,9,1,9,1,5,4,5,2,1,1,1,6)
Any ideas how to solve this problem?
Cheers, S.B.
-----Ursprüngliche Nachricht-----
Von: David Winsemius [mailto:[email protected]]
Gesendet: Donnerstag, 27. Oktober 2011 16:44
An: Duncan Murdoch
Cc: Samir Benzerfa; [email protected]
Betreff: Re: [R] question R regarding consecutive numbers
On Oct 27, 2011, at 9:21 AM, Duncan Murdoch wrote:
On 27/10/2011 8:43 AM, Samir Benzerfa wrote:
Hi everyone
Do you know about any possibility in R to check for consecutive
numbers in
vectors? That is, I do not only want to count the number of
observations in
total (which can be done table(x)), but I also want to count for
instance
how many times that vector contains a certain number consecutively.
For example in the following vector x the number "1" appears 7
times.
However, I want to check for instance how many times two
consecutive 1's
appear in the vector, which would actually be two times the case in
the
below vector.
x=c(1,1,3,4,9,1,9,1,5,4,5,2,1,1,1,6)
Any ideas for this issue?
How about this?
runs <- rle(x)
with(runs, table(values, lengths))
And to go even a bit further, the table function returns a matrix
which can be addressed to yield the specific answer requested:
with(runs, table(values, lengths))["1",2]
[1] 1 # m=number of exactly runs if length 2
sum( tbl["1", 2:ncol(tbl)] )
[1] 2 # number of runs of length two or more.
--
David
lengths
values 1 2 3
1 2 1 1
2 1 0 0
3 1 0 0
4 2 0 0
5 2 0 0
6 1 0 0
9 2 0 0
Duncan
______________________________________________
[email protected] 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.
David Winsemius, MD
West Hartford, CT
______________________________________________
[email protected] 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.
______________________________________________
[email protected] 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.
David Winsemius, MD
West Hartford, CT
______________________________________________
[email protected] 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.
