[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [igraph] Re: alpha in power.law.fit
From: |
Gábor Csárdi |
Subject: |
Re: [igraph] Re: alpha in power.law.fit |
Date: |
Thu, 5 Mar 2009 18:08:35 +0100 |
I think so, but are you sure that 'location' is actually 'alpha'? If
you use ppareto from the VGAM package, then the 'location' parameter
should be calculated from the normalization criteria, IMHO.
Btw., why don't you directly fit a Pareto distribution to the data? I
am sure that there is an R package that can do this, probably take a
look at 'degreenet' first.
G.
On Thu, Mar 5, 2009 at 5:42 PM, Simone Gabbriellini
<address@hidden> wrote:
> Thanks Gabor,
>
> btw, is it correct to assume that the k parameter is equal to alpha-1?
>
> simone
>
> 2009/3/5 Gábor Csárdi <address@hidden>:
>> Yep, coef(fit) is slightly better, as it likely works with the results
>> of many kind of fitting functions.
>>
>> Best,
>> G.
>>
>> On Thu, Mar 5, 2009 at 5:20 PM, Simone Gabbriellini
>> <address@hidden> wrote:
>>> SOLVED...
>>>
>>> it was easy...
>>>
>>>> fit<-power.law.fit(x)
>>>> address@hidden
>>> alpha
>>> 1.754803
>>>
>>> best regards,
>>> simone
>>>
>>> 2009/3/5 Simone Gabbriellini <address@hidden>:
>>>> hi list,
>>>>
>>>> I'd like to use the alpha coefficient I've found with power.law.fit(),
>>>> but I am not able to extract it from the mle object... what is the
>>>> right sintax?
>>>>
>>>> I need it in order to plot the distribution with:
>>>>
>>>> plot(ppareto(table(my.data.frame$score), location=alpha, shape=
>>>> alpha-1), type="p")
>>>>
>>>> thanks,
>>>> simone
>>>>
>>>
>>>
>>> _______________________________________________
>>> igraph-help mailing list
>>> address@hidden
>>> http://lists.nongnu.org/mailman/listinfo/igraph-help
>>>
>>
>>
>>
>> --
>> Gabor Csardi <address@hidden> UNIL DGM
>>
>>
>> _______________________________________________
>> igraph-help mailing list
>> address@hidden
>> http://lists.nongnu.org/mailman/listinfo/igraph-help
>>
>
>
> _______________________________________________
> igraph-help mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/igraph-help
>
--
Gabor Csardi <address@hidden> UNIL DGM