[GRASS-stats] Re: [GRASS-user] Testing i.pca ~ prcomp(), m.eigensystem ~ princomp()

[Roger Bivand]

On Tue, 10 Mar 2009, Nikos Alexandris wrote:

> On Tue, 2009-03-03 at 14:26 +0100, Nikos Alexandris wrote:
>> On Tue, 2009-03-03 at 13:18 +0100, Markus Neteler wrote:
>>> On Tue, Mar 3, 2009 at 12:26 PM, Hamish <hamish_b at yahoo.com> wrote:
>>> ...
>>>>
>>>> it will be really good to finally have all this documented.
>>>
>>> I find it hard to follow these long mails. Why not enjoying the
>>> GRASS Wiki to stabilize the documentation and comparisons?
>>>
>>> Markus
>>
>> Yes, why not? Hmmm, you mean to put these stuff already in the Wiki
>> before we are sure about the one last and very important variable
>> (=eigenvalues reported by  i.pca)?
>>
>> Kind regards, Nikos
>
> I've started the PCA grass-wiki page. I am trying to build it... step by
> step. Expert advice is always welcome and highly appreciated.
>
> http://grass.osgeo.org/wiki/Principal_Component_Analysis

Good, thanks. There you say that you are using "some MODIS surface 
reflectance products". I guess it will be easier to check things if the 
data (GRASS location) are available, so that others can try the same 
calculations. Would it be possible to make one or more test sets 
available, and link them from thw Wiki?

Roger

>
> Kind regards, Nikos
>
> _______________________________________________
> grass-stats mailing list
> grass-stats at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-stats
>

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no