R help - Aug 2007 - quntile(table)?

Hi,

I have data in the following form:

  index  count
    -7      32
     1    9382
     2    2192
     7     190
    11     201

I'd like to get quantiles from the data.  I thought about something like
this:

  index <- c(-7, 1, 2, 7, 11)
  count <- c(32,  9382, 2192, 190, 201)
  quantile(rep(index, count))

It answers correctly, but I feel it's wasteful especially when count
is generally large.  So, my question is, is there a way to get
quantiles directly from this table (without coding at a low level)?

Thanks,
Seung

You could use:

require(quantreg)
  rq(index ~ 1, weights=count, tau=0:5/5)

url:    www.econ.uiuc.edu/~roger            Roger Koenker
email    rkoenker at uiuc.edu            Department of Economics
vox:     217-333-4558                University of Illinois
fax:       217-244-6678                Champaign, IL 61820


On Aug 28, 2007, at 9:22 AM, Seung Jun wrote:
> Hi,
>
> I have data in the following form:
>
>   index  count
>     -7      32
>      1    9382
>      2    2192
>      7     190
>     11     201
>
> I'd like to get quantiles from the data.  I thought about something  
> like this:
>
>   index <- c(-7, 1, 2, 7, 11)
>   count <- c(32,  9382, 2192, 190, 201)
>   quantile(rep(index, count))
>
> It answers correctly, but I feel it's wasteful especially when count
> is generally large.  So, my question is, is there a way to get
> quantiles directly from this table (without coding at a low level)?
>
> Thanks,
> Seung
>
> ______________________________________________
> 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
> and provide commented, minimal, self-contained, reproducible code.

See the wtd.quantile function in the Hmisc package.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at intermountainmail.org
(801) 408-8111
 
 
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Seung Jun
> Sent: Tuesday, August 28, 2007 8:23 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] quntile(table)?
> 
> Hi,
> 
> I have data in the following form:
> 
>   index  count
>     -7      32
>      1    9382
>      2    2192
>      7     190
>     11     201
> 
> I'd like to get quantiles from the data.  I thought about 
> something like this:
> 
>   index <- c(-7, 1, 2, 7, 11)
>   count <- c(32,  9382, 2192, 190, 201)
>   quantile(rep(index, count))
> 
> It answers correctly, but I feel it's wasteful especially 
> when count is generally large.  So, my question is, is there 
> a way to get quantiles directly from this table (without 
> coding at a low level)?
> 
> Thanks,
> Seung
> 
> ______________________________________________
> 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
> and provide commented, minimal, self-contained, reproducible code.
>