[R] getting the unique values and counts from a vector

[Ravi Varadhan]

Hi,
"table" should do it.

> x<-c(2 ,1 ,2, 1, 4 ,2 ,1, 4 ,1 ,1)
> table(x)
x
1 2 4 
5 3 2 

--------------------------------------------------------------------------
Ravi Varadhan, Ph.D.
Assistant Professor,  The Center on Aging and Health
Division of Geriatric Medicine and Gerontology
Johns Hopkins University
Ph: (410) 502-2619
Fax: (410) 614-9625
Email:  rvaradhan at jhmi.edu
--------------------------------------------------------------------------
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-
> bounces at stat.math.ethz.ch] On Behalf Of Ravi.Vishnu at outokumpu.com
> Sent: Friday, May 20, 2005 10:48 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] getting the unique values and counts from a vector
> 
> Hi all,
> >From a vector, I want to get the unique values and the counts of these
> unique values in the vector. For example,
> x<-c(2 ,1 ,2, 1, 4 ,2 ,1, 4 ,1 ,1)
> xu<-unique(x)
> xn<-numeric(length(xu))
> for (i in 1:length(xu)) {xn[i]<-length(which(x==xu[i]))}
> There must be a very much simpler method of doing this. Can somebody
> direct me to the functions that I must read in order to do operations of
> these sort.
> Thanks,
> Ravi Vishnu
> 
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