POWER SPECTRUM 2D FIELD

Is there someone who can help me to calculate and plot the power
spectrum of a 2D field?
I have already calculated the power spectral density (it's a 3D
function) of the matrix through the FFt of the same matrix, you can
use various techniques, for example using the periodogram, but now i
need the power spectrum of the field so...? How can i do?

(PS: for example in turbulence you give a 3D field and you can compute
the power spectra, how? Therefore I am in the 2D input case)

Is there someone who have already done any Matlab or Mathematica
routine?

Thank you very much,

Matteo.


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     Matteo Convertino

     PhD student, advisors: Prof. Andrea Rinaldo and Prof. Amos
Maritan
     IMAGE Dept. and International Center for Hydrology "Dino Tonini"
     Via Loredan 20, I-35131 Padova
     Graduate School in Civil and Environmental Engineering Sciences
     University of Padova, Italy

     http://digilander.libero.it/matconv/
     http://digilander.libero.it/matconv/ThesisMaterials.html
     http://www.image.unipd.it/scuola_di_dottorato/
     Office phone: +39 049 8275445
     Fax: +39 049 8275446
     Personal phone: +39 349 1750320
     E-mail: convertino@[EMAIL PROTECTED]
 and matteo.convertino@[EMAIL PROTECTED]
     Skype ID: matteo_convertino
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