[R] R results explanation

[Duncan Murdoch]

On 07/06/2011 4:14 AM, mpavlic wrote:
> Hi all,
>
>
> this might be a stupid question, but still.
>
> Everytime i find some new function it's prettty easy to understand how to
> use the syntax and to perform a text. Even the general idea of what the
> function does is pretty easy to understand, but i can not find an
> explanation (detailed explanation) of the R output for each function. For
> example, a function fitdistr() in MASS package i testing the data against
> the distributions (wanted distribution).
>
> fitdistr(k, "lognormal")
>>      meanlog        sdlog
>    3.150725905   0.759584332
>   (0.012839319) (0.009078769)
>
> But when i get the result I can not find what these numbers mean. Is there a
> explanation somewhere in R help for each function?

The Value section of the help page describes what the function returns. 
The help page for fitdistr has

Value:

      An object of class ‘"fitdistr"’, a list with four components,

estimate: the parameter estimates,

       sd: the estimated standard errors,

     vcov: the estimated variance-covariance matrix, and

   loglik: the log-likelihood.


You should be aware that objects often print only part of their value; 
the rest can be extracted using the usual methods, e.g.

fit <- fitdistr(k, "lognormal")
fit$loglik

will print the log likelihood.

This doesn't explain what "meanlog" and "sdlog" are; for that you need 
to know about the lognormal distribution, or consult the reference on 
the help page.

Duncan Murdoch

>
> Thanks for the help, m
>
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