unpackbasiscoeff.sci

小波分解源代码

function x = UnpackBasisCoeff(basis,pkt)
// UnpackBasisCoeff -- Extract basis coefficients from packet table
//  Usage
//    x = UnpackBasisCoeff(basis,pkt)
//  Inputs
//    basis     basis tree
//    pkt       packet table (wavelet- or cosine-)
//  Outputs
//    x         coefficients of signal in that basis
//
//  Copyright Aldo I Maalouf

	[n,L] = size(pkt);
	x = zeros(1,n);
//
// initialize tree traversal stack
//
	dstack = zeros(1,2^L);
	bstack = zeros(1,2^L);
	k = 1;
	dstack(k) = 0;
	bstack(k) = 0;
//
	while(k > 0),
		d = dstack(k); b = bstack(k); k=k-1;
		if(basis(node(d,b)) == 0) ,  // terminal node
			   x(packet(d,b,n)) = pkt(packet(d,b,n),d+1)';
		else
			   k = k+1;
			   dstack(k) = d+1; bstack(k) = 2*b;
			   k = k+1;
			   dstack(k) = d+1; bstack(k) = 2*b+1;
		 end
	end
	endfunction