Radially averaged power spectrum of 2D real-valued matrix

Computes and plots radially averaged PSD of 2-D real matrix with a given spatial resolution.

Description

The radially averaged power spectrum (RAPS) is the direction-independent mean spectrum, i.e. the average of all possible directional power spectra. The radially averaged power spectrum provides a convenient means to view and compare information contained in 2-D spectra in 1-D. This function computes and plots the RAPS of an input matrix (does not consider corner values outside averaging radius). The image can be rectangular but must be 2-D (e.g., multi-color channel data is not supported). The spatial resolution of the data is also specified.

• MATLAB release: MATLAB 7.3 (R2006b)

[Stefano]

Hi, I found this to be faster, hope it helps, S.
%% code for fast radial averaging:
[xx,yy]=meshgrid(-1000:1000,-1000:1000);
rr=sqrt(xx.^2+yy.^2);
ri=floor(rr/100)+1;
N=numel(ri);
[~,~,iir]=unique(ri); %find unique values
Qt =sparse(1:N,iir,ones(N,1));

tic;Pf=(rr(:).'*Qt).';toc %radial average

[Angjelina Protik]

for r = 0:floor(dimMax/2)
    i{r + 1} = find(rho == r);
end
Pf = zeros(1, floor(dimMax/2)+1);
for r = 0:floor(dimMax/2)
    Pf(1, r + 1) = nanmean( imgfp( i{r+1} ) );
end
there is some bug in this part