I am trying to only fit this distribution to the data to see how well it
fits it. Getting the parameters is secondary. Did correct the square
brackets in the exponential equation but still get the same result. There is
only 1 variable to data2 and that is points. I am trying to fit this
distribution to points data scored by teams.

The result for any(data2 < 0.5 | data2 > 0.5+50) is TRUE.

Thanks
Abey


On Mon, Oct 4, 2010 at 11:33 AM, David Winsemius <dwinsemius@comcast.net>wrote:

>
> On Oct 3, 2010, at 3:47 PM, Abey George wrote:
>
>  Hi,
>>     I am trying to fit a Johnson SB distribution using fitdist function in
>> fitdistrplus Library. I have defined the Johnson SB distribution from (
>> http://www.ntrand.com/johnson-sb-distribution/) . But it gives me the
>> follwing errors. Any help would be appreciated
>>
>
> Are you really trying to estimate the bounding values as well as the gamma
> and delta parameters. Those would seem to be more likely determined by the
> nature of the problem, e.g., policy limits on the insured sums if this were
> a financial problem.
>
>
>
>> #xi = xi
>>
>
>  #lambda =l
>> #delta =d
>> #gamma = g
>>
>> djohn = function(x,xi,l,d,g)
>> (d/(l*sqrt(2*pi)*((x-xi)/l)*(1-((x-xi)/l))))*exp[-0.5*(g +
>> d*log(((x-xi)/l)/(1-((x-xi)/l))))^2]
>>
>
> You used exp[ ] where you probably wanted exp().
>
>
>
>> pjohn = function(x,xi,l,d,g)   pnorm(g + d*log(((x-xi)/l)/(1-((x-xi)/l))))
>>
>> qjohn = function(p,xi,l,d,g)   xi + (l*exp((qnorm(p) - g)/d))/(1 +
>> exp((qnorm(p) - g)/d))
>>
>> f1c <- fitdist(data2,"john",start=list(xi = 0.5 ,l = 50, d = 1, g = 1))
>>
>
> You have not given us the "data2" variables, so we have no way of checking
> whether any of them appear outside the range [epsilon, lambda+epsilon].
> Using your data2 vector, what are the results of :
>
> any(data2 < 0.5 | data2 > 0.5+50)   #?
>
>
>
>
>> Error in fitdist(data2, "john", start = list(xi = 0.5, l = 50, d = 1,  :
>>  the function mle failed to estimate the parameters,
>>               with the error code 100
>> In addition: Warning message:
>> In log(((x)/l)/(1 - ((x)/l))) : NaNs produced
>>
>>
>> Cheers
>> AG
>>
>
>
> David Winsemius, MD
> West Hartford, CT
>
>


-- 
Abey George

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