From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>

Date: Mon Mar 14 2011 - 14:26:26 MDT

Date: Mon Mar 14 2011 - 14:26:26 MDT

Hello,

D. S. Wilks

Statistical Methods in the Atmospheric Sciences

Academic Press (Elsevier), 2006

pp 477-479:

Section 11.2.2: Simultaneous PCA for Multiple Fields

I would suggest you look at results from both the

correlation and covariance matrices.

Good luck

On 03/14/2011 12:17 PM, Malte Stuecker wrote:

*> Hi everyone,
*

*>
*

*> I have done EOF analysis for scalar fields (e.g. SST) with the NCL EOF
*

*> functions, however I am struggling with the concept of how to do an
*

*> EOF analysis of vector data (e.g. analyzing the u- and v- component of
*

*> ocean current data at the same time). I understand that it is possible
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*> to represent both quantities as a complex number, however I am not
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*> sure about the practical (=programming) approach. Most literature that
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*> I found seems to cover only the theory, but there are not many 'HOW TO
*

*> DO' sources out there.
*

*> My idea was to just combine the u and v fields in one matrix along one
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*> of the spatial axis (e.g. combining a u (20E-40E,20S-20N) and v field
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*> (20E-40E,20S-20N) to a (20E-40E,40S-40N) field), calculate the EOF and
*

*> afterwards split the eigenvector matrix into the u- and v- component
*

*> and plot the resulting vectors. In this case, is it possible to
*

*> interpret the eigenvalues + eigenvectors in the same way as you would
*

*> doing an EOF analysis on a scalar field? It would be great if anyone
*

*> could point me to some step-by-step introduction to this type of
*

*> problem or knows maybe some software packages other than NCL that
*

*> could deal with this type of analysis comfortably.
*

*> Thank you very much in advance!
*

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Received on Mon Mar 14 14:26:30 2011

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