[R] Confidence Interval of Specral Density Plot

[David Winsemius]

On May 21, 2011, at 3:27 AM, Zablone Owiti wrote:

> Dear Users,
>
> I wish to know at what confidence level is the  confidence interval
> provided in the  Spectrum function (plot.spec) plots.

The default level is clearly indicated in the arguments of the Usage  
section on the help page of plot.spec.

> The only information provided in the help regarding this is : a  
> confidence
> interval will be plotted by plot.spec: this is asymmetric, and the  
> width of
> the centre mark indicates the equivalent bandwidth.

The authors of R consider the code to be the final arbiter of "what  
documentation is provided". The code is readily available, since the  
plot.spec function is visible,  and it is not at all difficult to find  
the function that calculates the CI, since it is right at the top when  
you type: plot.spec

>
> Attached is an example plot with the BLUE confidence interval.

Nothing attached, but in this case I don't think it would add  
anything. You probably need to read the Posting Guide before  
attempting to attach items. The mail-server is very picky about what  
it will accept.

>
> Thanks
> ----------------------------
>
> ZABLONE OWITI
>
> GRADUATE STUDENT
>


David Winsemius, MD
West Hartford, CT