Home > matutils > interf > powspec.m

powspec

PURPOSE ^

[ps,rb]=powspec(ad,ft)

SYNOPSIS ^

function [ps,rb]=powspec(ad,ft)

DESCRIPTION ^

 [ps,rb]=powspec(ad,ft)

 Make a 1D power spectrum of a 2D array

 Try to make the bins the same width as ft ones and
 the centers run from just below 0 to just above maxr

 Twin function is realize to go the other way.

CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function [ps,rb]=powspec(ad,ft)
0002 % [ps,rb]=powspec(ad,ft)
0003 %
0004 % Make a 1D power spectrum of a 2D array
0005 %
0006 % Try to make the bins the same width as ft ones and
0007 % the centers run from just below 0 to just above maxr
0008 %
0009 % Twin function is realize to go the other way.
0010 
0011 m=max(ad.u_r(:));
0012 top=m+ad.del_u/2;
0013 bot=-ad.del_u/2;
0014 span=top-bot;
0015 nbin=round(span/ad.del_u);
0016 
0017 % Allow for taking the powspec of a stack of images
0018 u_r=repmat(ad.u_r,[1,1,size(ft,3)]);
0019 
0020 % Remember abs(x).^2=x.*conj(x)=real(x).^2+imag(x).^2
0021 % Second is fastest
0022 [rb,ps]=hprof(u_r,ft.*conj(ft),nbin,bot,top);
0023 
0024 % Kludge to make the first and last bin centers span
0025 % 0 and maxr
0026 rb(1)=-ad.del_u/1e3;
0027 rb(end)=m+ad.del_u/1e3;
0028 
0029 return

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