R help - Apr 2007 - Problem with dgamma ?

Hi All, 
     Here 's what I got using dgamma function : 
> nu<-.2
> nu*log(nu)-log(gamma(nu))+(nu-1)*log(1)-nu*(1)
[1] -2.045951
> dgamma(1,nu,nu,1)
[1] 0.0801333
> dgamma(1,nu,nu,0)
[1] NaN
Warning message:
NaNs produced in: dgamma(x, shape, scale, log) 

Could anyone tell me what is wrong here ?
I am using R-2.4.1 on windows XP.

Thanks a lot.

dgamma(x=1, shape=nu, rate=nu, log=TRUE)
[1] -2.045951

This is a good example of why you should call parameters by name.

Ted.

Tong Wang wrote on 04/23/2007 01:59 PM:
> Hi All, 
>      Here 's what I got using dgamma function : 
>
>   
>> nu<-.2
>> nu*log(nu)-log(gamma(nu))+(nu-1)*log(1)-nu*(1)
>>     
> [1] -2.045951
>
>   
>> dgamma(1,nu,nu,1)
>>     
> [1] 0.0801333
>
>   
>> dgamma(1,nu,nu,0)
>>     
> [1] NaN
> Warning message:
> NaNs produced in: dgamma(x, shape, scale, log) 
>
> Could anyone tell me what is wrong here ?
> I am using R-2.4.1 on windows XP.
>
> Thanks a lot.
>
> ______________________________________________
> 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.
>   

-- 
 Dr E.A. Catchpole  
 Visiting Fellow
 Univ of New South Wales at ADFA, Canberra, Australia
    _	  and University of Kent, Canterbury, England
   'v'	  - www.pems.adfa.edu.au/~ecatchpole          
  /   \	  - fax: +61 2 6268 8786		   
   m m    - ph:  +61 2 6268 8895

Tong Wang wrote:
> Hi All, 
>      Here 's what I got using dgamma function : 
>
>   
>> nu<-.2
>> nu*log(nu)-log(gamma(nu))+(nu-1)*log(1)-nu*(1)
>>     
> [1] -2.045951
>
>   
>> dgamma(1,nu,nu,1)
>>     
> [1] 0.0801333
>
>   
>> dgamma(1,nu,nu,0)
>>     
> [1] NaN
> Warning message:
> NaNs produced in: dgamma(x, shape, scale, log) 
>
> Could anyone tell me what is wrong here ?
>   
Did you intend the 4th argument to match the log formal argument? It 
doesn't:

 > args(dgamma)
function (x, shape, rate = 1, scale = 1/rate, log = FALSE)
NULL

> I am using R-2.4.1 on windows XP.
>
> Thanks a lot.
>
> ______________________________________________
> 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.
>