wtmm.m

由WAVELAB提供的计算连续小波变换,包括求小波脊的MATLAB程序工具箱.

function maxmap = WTMM(cwt,par)
% WTMM -- Wavelet Transform Maximum Modulus
%  Usage
%    maxmap = WTMM(cwt,par)
%  Inputs
%    cwt    Output of CWT
%    par    optional. If present, keep thresholds only
%           above a certain value. UNUSED AT MOMENT
%  Outputs
%    maxmap binary array indicating presence of max or not
%
%  Description
%    Used to calculate fractal exponents etc. 
%
	
	sz = size(cwt);
	nscale = sz(2);
	n = sz(1);
	
	maxmap = zeros(sz);

	t      = 1:n;
	tplus  = rshift(t);
	tminus = lshift(t);
	cwt    = abs(cwt);
		
	for k=1:nscale,
	     localmax =  cwt(t,k) > cwt(tplus,k) & cwt(t,k) > cwt(tminus,k) ;
		 maxmap(t,k) = localmax(t);
	end
	
	
	
    
    
 
 
%
%  Part of Wavelab Version 850
%  Built Tue Jan  3 13:20:39 EST 2006
%  This is Copyrighted Material
%  For Copying permissions see COPYING.m
%  Comments? e-mail [e-mail]