[R] kde on Torus

[Tim Gruene]

Dear David,

thanks for the hint. As far as I understand the circular kernels apply only to
one-dimensional data, don't they?

Tim

On Wed, Jul 28, 2010 at 08:57:40AM -0400, David Winsemius wrote:
>
> On Jul 28, 2010, at 7:55 AM, Tim Gruene wrote:
>
>> Hello,
>>
>> I have 2D-data on a torus, i.e. they are scattered within [0:2pi) and 
>> are
>> supposed to be periodic with period 2pi.
>>
>> Is there a way in R for a kernel density estimation for such data? I  
>> found this
>> article http://www.dmqte.unich.it/personal/dimarzio/density46.pdf
>> but
>> a) I don't fully understand the article (my knowledge in statistics is 
>> poor)
>> b) I did not understand which Eq. represents the kernel(s)
>> c) I do not now R well enough to understand whether I can use kde2d or 
>> nprudens
>>   with an arbitrary kernel
>>
>> My simple-minded attempt was to extend the data to [-2pi:4pi) and then 
>> use
>> kde2d, but I am wondering
>> a) how accurate is this
>> b) is there a way to do it properly on a torus.
>
> You could take a look at the density function within the package,  
> "circular".
>
> -- 
>
> David Winsemius, MD
> West Hartford, CT

-- 
--
Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen

GPG Key ID = A46BEE1A

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