On 03/01/2012 1:33 PM, Albyn Jones wrote:
What do quantiles mean here?  If you have a mixture density, say

     myf<- function(x,p0) p0*dbeta(x,2,6) + (1-p0)*dbeta(x,6,2)

then I know what quantiles mean.  To find the Pth quantile use uniroot
to solve for the x such that myf(x,p0) - P =0.

You would want to integrate first...

Duncan Murdoch

albyn

Quoting VictorDelgado<victor.m...@fjp.mg.gov.br>:

>
>  Gerhard wrote
>>
>>
>>  Suppose I create a custom function, consisting of two beta-distributions:
>>
>>  myfunction<- function(x) {
>>    dbeta(x,2,6) + dbeta(x,6,2)
>>  }
>>
>>  How can I calculate the quantiles of myfunction?
>>
>>  Thank you in advance,
>>
>>  Gerhard
>>
>>
>
>  Gehard, if do you want to know the quantiles of the new distribution created
>  by "myfunction". Maybe you can also do:
>
>  x<- seq(0,1,.01) # insert your 'x'
>  q<- myfunction(x)
>  # And:
>  quantile(x)
>
>        0%      25%      50%      75%     100%
>  0.000000 1.476177 2.045389 2.581226 2.817425
>
>  # This gives the sample quantiles. You can also look foward to simulations
>  (like Bert Gunter had suggested) to know better the properties of
>  distributions quantiles obtained after 'myfunction'.
>
>
>
>  -----
>  Victor Delgado
>  cedeplar.ufmg.br P.H.D. student
>  www.fjp.mg.gov.br reseacher
>  --
>  View this message in context:
>  
http://r.789695.n4.nabble.com/calculate-quantiles-of-a-custom-function-tp4256887p4257551.html
>  Sent from the R help mailing list archive at Nabble.com.
>
>  ______________________________________________
>  R-help@r-project.org 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.
>
>

______________________________________________
R-help@r-project.org 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.

______________________________________________
R-help@r-project.org 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.

Reply via email to