Re: [R] How to fit a random data into Beta distribution?

From: Steven Kennedy <stevenkennedy2263_at_gmail.com>
Date: Wed, 04 May 2011 19:46:54 +1000

Hi Shekhar,

It looks from your error that you have values outside the range 0 to 1. The beta distribution is only defined between 0 and 1. Can you please post your data set (or at least a portion of it)?

On Wed, May 4, 2011 at 3:24 PM, Shekhar <shekhar2581_at_gmail.com> wrote:
> Hi Steven,
> Thanks for the quick reply. i have tried but
> its giving me error--->Error in optim(x = c(38.1815173696765,
> -12.7988197976440, -3.88212459045077,  :
>  initial value in 'vmmin' is not finite
>
>
> i have tried something like this:
>
> library(MASS)
> x<-rnorm(n=100,mean=10,sd=20);
> fitdistr(x,dbeta,start=list(shape1=1,shape2=1)
>
> Please correct me if my understanding is wrong:
> In the fitdistr fucntion we are providing the initial values of the
> Beta distribution parameters as shape1=1 and shape2=1. This function
> will try to fit the data and give us the new parameters of Beta
> distribution that approximately fits this data.
>
>
> I have tried the function with other distribution like Normal, Gamma,
> Weibull...its working fine..
>
> Regards,
> Som Shekhar
>
>
>
>
> On May 4, 1:25 am, Steven Kennedy <stevenkennedy2..._at_gmail.com> wrote:
>> library(MASS)
>> fitdistr(x,"beta",list(shape1=1,shape2=1))
>>
>>
>>
>> On Tue, May 3, 2011 at 9:44 PM, Shekhar <shekhar2..._at_gmail.com> wrote:

>>
>> > Hi,
>> > I have some random data and i want to find out the parameters of Beta
>> > distribution ( a and b) such that this data approximately fits into
>> > this distribution. I have tried by plot the histograms and graph, but
>> > it requires lot of tuning and i am unable to do that. can anyone tell
>> > me how to do it programmitically in R?
>>
>> > Regards,
>> > Som Shekhar
>>
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>>
>> ______________________________________________
>> R-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
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>
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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>



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