R help - Nov 2010 - count occurrence and distance of characters in string

Hello all,

I want to know how often one character occurs in a given string
and the distance from between every two occurences. (distance = other
characters between them).

thanks

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Immanuel
> Sent: Thursday, November 04, 2010 3:42 PM
> To: r-help at r-project.org
> Subject: [R] count occurrence and distance of characters in string
> 
> Hello all,
> 
> I want to know how often one character occurs in a given string
> and the distance from between every two occurences. (distance = other
> characters between them).
> 
> thanks
> 
Without a reproducible example, I can only guess.  But this should get you
started.

s <- 'abcdeabcxdeabcdeaxabcdeabcdeabcdxeabc'
chr.pos <- which(unlist(strsplit(s,NULL)) == 'x')
chr.count <- length(chr.pos)
chr.dist <- diff(chr.pos)-1
chr.pos 
chr.count 
chr.dist

Hope this is helpful,

Dan

Daniel J. Nordlund
Washington State Department of Social and Health Services
Planning, Performance, and Accountability
Research and Data Analysis Division
Olympia, WA 98504-5204

On Thu, 4 Nov 2010, Immanuel wrote:
> Hello all,
>
> I want to know how often one character occurs in a given string
> and the distance from between every two occurences. (distance = other
> characters between them).
You should provide "commented, minimal, self-contained, reproducible
code"
as asked.

And especially for a question like this one with many simple answers that 
RespondeRs will shower you with if only you give them a starting point.

Use tapply, strsplit, seq, nchar, unlist, diff, "-", and table for one
way.

Chuck
>
> thanks
>
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>
Charles C. Berry                            Dept of Family/Preventive Medicine
cberry at tajo.ucsd.edu			    UC San Diego
http://famprevmed.ucsd.edu/faculty/cberry/  La Jolla, San Diego 92093-0901