R help - Mar 2006 - Compute quantiles with values and correspondent frequencies

Dear List, 
quantile(x) function allows to obtain specified quantiles of a vector of
observations x.

Is there an analogous function to compute quantiles in the case one have the
vector of the observations x and the correspondent vector f of relative
frequencies ?

Thank you

Paolo Radaelli



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On Fri, 3 Mar 2006, Paolo Radaelli wrote:
> Dear List, quantile(x) function allows to obtain specified quantiles of
> a vector of observations x.
> 
> Is there an analogous function to compute quantiles in the case one have
> the vector of the observations x and the correspondent vector f of
> relative frequencies ?
Just use rep():

x <- rpois(100, 4) # data
quantile(x)
tx <- table(x) # frequencies (need to be integer counts)
tx
v <- as.numeric(names(tx)) # values
quantile(rep(v, as.integer(tx)))

You have v and tx, so this should work.
> 
> Thank you
> 
> Paolo Radaelli
> 
> 
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
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> PLEASE do read the posting guide!
http://www.R-project.org/posting-guide.html
> 
-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no

Roger Bivand wrote:
> On Fri, 3 Mar 2006, Paolo Radaelli wrote:
> 
> 
>>Dear List, quantile(x) function allows to obtain specified quantiles of
>>a vector of observations x.
>>
>>Is there an analogous function to compute quantiles in the case one have
>>the vector of the observations x and the correspondent vector f of
>>relative frequencies ?
> 
> 
> Just use rep():
> 
> x <- rpois(100, 4) # data
> quantile(x)
> tx <- table(x) # frequencies (need to be integer counts)
> tx
> v <- as.numeric(names(tx)) # values
> quantile(rep(v, as.integer(tx)))
> 
> You have v and tx, so this should work.
> 
> 
>>Thank you
>>
>>Paolo Radaelli
>>
>>
>>
>>	[[alternative HTML version deleted]]
>>
>>______________________________________________
>>R-help at 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
>>
> 
> 
Look at wtd.quantile in the Hmisc package.

Frank

-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University