wtmm.sci

小波分解源代码

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. 
//
//  Copyright Aldo I Maalouf

	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
	endfunction