[R] Plotting skewed normal distribution with a bar plot

R. Michael Weylandt michael.weylandt at gmail.com
Fri Nov 4 18:57:24 CET 2011


You might want to check again: I'm running fGarch on 2.13.2, Mac OSX 10.5.8.

Michael

On Fri, Nov 4, 2011 at 9:36 AM, Steve Friedman <skfglades at gmail.com> wrote:
> Hi Michael,
>
> Thanks for pointing me fGarch.  I actually started there, but it is not yet
> available for 2.13.2 so I went directly to the (sn-package).
>
> I've briefly explored your suggestion and think it will work.
>
> Thanks
> Steve
>
> On Nov 3, 2011 10:41 PM, "R. Michael Weylandt" <michael.weylandt at gmail.com>
> wrote:
>>
>> It seems like you'll need to apply some sort of MLE to estimate the
>> parameters directly from the data before using dsn() to get the
>> density. This might help with some of it:
>> http://help.rmetrics.org/fGarch/html/snorm.html
>>
>> Michael
>>
>> On Thu, Nov 3, 2011 at 2:54 PM,  <Steve_Friedman at nps.gov> wrote:
>> >
>> > Hi,
>> >
>> > I need to create a plot (type = "h")  and then overlay a skewed-normal
>> > curve on this distribution, but I'm not finding a procedure to
>> > accomplish
>> > this. I want to use the plot function here in order to control the bin
>> > distributions.
>> >
>> > I have explored the sn library and found the dsn function.  dsn uses
>> > known
>> > location, scaling and shape parameters associated with a given input
>> > vector
>> > of probabilities.  However, how can I calculate the skewed-normal curve
>> > if
>> > I don't know these parameters in advance?
>> >
>> > Is there another function to calculate the skew-normal, perhaps in a
>> > different package?
>> >
>> >
>> > I'm working with R 2.13.2 on a windows based machine.
>> >
>> > Steve Friedman Ph. D.
>> > Ecologist  / Spatial Statistical Analyst
>> > Everglades and Dry Tortugas National Park
>> > 950 N Krome Ave (3rd Floor)
>> > Homestead, Florida 33034
>> >
>> > Steve_Friedman at nps.gov
>> > Office (305) 224 - 4282
>> > Fax     (305) 224 - 4147
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> > PLEASE do read the posting guide
>> > http://www.R-project.org/posting-guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>> >
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>



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