From: Ted Harding <Ted.Harding_at_nessie.mcc.ac.uk>

Date: Fri 11 Mar 2005 - 22:37:50 EST

E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Mon Mar 14 09:57:36 2005

Date: Fri 11 Mar 2005 - 22:37:50 EST

On 11-Mar-05 Mohammad Ehsanul Karim wrote:

*> Dear List Members,
**>
**> I need some help about programming in S language. My
**> problem is as follows:
**>
**> I have meteorological data (about rainfall measurement
**> each day from 1989-2002), say like
**> http://www.angelfire.com/ab5/get5/data.rainfall.txt
**> or http://www.angelfire.com/ab5/get5/R.rainfall.txt
**> in a sequence of 0(denoting dry day)'s and 1(denoting
**> wet day)'s. I want to construct a frequency
**> distribution table of various lengths
**> (1,2,3,4,5,6,7,8,9,or more) of observed wet spells
**> (number of successive 1's) and dry spells (number of
**> successive 0's) occurring in data.
**>
**> How should i proceed? Is there any existing
**> program/function/package to solve such problem (seems
**> like the algorithm should be similar to statistical
**> run test)?
**>
*

> Any suggestion, direction, references, help, replies

> will be highly appreciated.

The function 'rle' will do what you ask: see ?rle

For example, if X is your sequence of 0s and 1s,

table(rle(X)$lengths)

will produce a frequency table of lengths of runs. E.g.

X<-sample(c(0,1),5000,replace=TRUE)

table(rle(X)$lengths)

1 2 3 4 5 6 7 8 9 10 11 1181 644 333 168 83 35 15 5 3 3 3

(But -- see recent postings -- be careful about using

hist(rle(X)$lengths)

!!!)

Hoping this helps,

Ted.

E-Mail: (Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861

Date: 11-Mar-05 Time: 11:37:50 ------------------------------ XFMail ------------------------------ ______________________________________________R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Mon Mar 14 09:57:36 2005

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