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Wavelet Scale Spectra

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Wavelet Scale Spectra

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15 Feb 2012 (Updated )

Compute wavelet scale spectra from segmented discrete wavelet transform (Screenshot).

FracPartition(cw,mm,q)
function z = FracPartition(cw,mm,q)
% FracPartition -- Fractal Partition Function based on wavelet modulus maxima
%  Usage
%    z = FracPartition(cw,mm,q)
%  Inputs
%    cw        matrix output by CWT
%    mm        maxmap output by MMWT
%    q         optional list of exponents default linspace(-2,5,61)
%  Outputs
%    z         matrix nexp by nscale of z(q,a)
%
%  Description
%    z(q,a) = sum_i( |CWT(a,b(i))|^q ),  where b = (b(i)) is a list
%    of wavelet transform maxima  
%    section 6.5.2 of Mallat' book
%
%  See Also
%    RWT, MM_RWT
%

	if nargin < 3,
	   q = linspace(-2,5,61);
	end
	
	[n,nscale] = size(cw);
	for k=1:nscale,
	    j = find(mm(:,k));
		if ~isempty(j),
			C = abs(cw(j,k));
			for i=1:length(q),
				z(i,k) = sum(C .^ q(i));
			end
		else
			z(:,k) = eps^q;
		end
	end
	      
% Written by Maureen Clerc and Jerome Kalifa, 1997
% clerc@cmapx.polytechnique.fr, kalifa@cmapx.polytechnique.fr

    
    
 
 
%
%  Part of Wavelab Version 850
%  Built Tue Jan  3 13:20:40 EST 2006
%  This is Copyrighted Material
%  For Copying permissions see COPYING.m
%  Comments? e-mail wavelab@stat.stanford.edu 

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