R help - Mar 2006 - Sub-vector

Dear list,

Given a vector of logical values, say
>a <- c(TRUE,TRUE,TRUE,FALSE,FALSE,FALSE,FALSE,TRUE,TRUE,TRUE)
Are there any R functions that can tell whether there are two or more
"TRUE" in a row in this vector?

Thanks,

Wuming

Wuming,

which(a) will identify the TRUE values and sum(a) will tell you how many
TRUE values there are.

David


-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Wuming Gong
Sent: 29 March 2006 18:21
To: r-help at stat.math.ethz.ch
Subject: [R] Sub-vector


* Please Note : This message was received from the Internet *
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Dear list,

Given a vector of logical values, say
>a <- c(TRUE,TRUE,TRUE,FALSE,FALSE,FALSE,FALSE,TRUE,TRUE,TRUE)
Are there any R functions that can tell whether there are two or more
"TRUE" in a row in this vector?

Thanks,

Wuming

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stat.ethz.ch/mailman/listinfo/r-help
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Try this:

with(rle(a), any(lengths[values]>1))


On 3/29/06, Wuming Gong <wuming.gong at gmail.com>
wrote:
> Dear list,
>
> Given a vector of logical values, say
>
> >a <- c(TRUE,TRUE,TRUE,FALSE,FALSE,FALSE,FALSE,TRUE,TRUE,TRUE)
>
> Are there any R functions that can tell whether there are two or more
> "TRUE" in a row in this vector?
>
> Thanks,
>
> Wuming
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
R-project.org/posting-guide.html
>

On Thu, 30 Mar 2006, Wuming Gong wrote:
> Dear list,
> 
> Given a vector of logical values, say
> 
> >a <- c(TRUE,TRUE,TRUE,FALSE,FALSE,FALSE,FALSE,TRUE,TRUE,TRUE)
> 
> Are there any R functions that can tell whether there are two or more
> "TRUE" in a row in this vector?
?rle (a very useful function)

aa <- rle(a)
any(aa$values & aa$lengths > 1)

> 
> Thanks,
> 
> Wuming
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
R-project.org/posting-guide.html
> 
-- 
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