calcwplocation.sci

来自「小波分解源代码」· SCI 代码 · 共 30 行

function pos = CalcWPLocation(d,b,k,qmf,n)
// CalcWPLocation -- Calculate location of wavelet packet entry
//  Usage
//    CalcWPLocation(d,b,k,qmf,n)
//  Inputs
//    d          depth index
//    b          block index
//    k          coef index
//    qmf        qmf filter
//    n          signal length
//  Outputs
//    pos        position in wp data structure
// 
//  Copyright Aldo I Maalouf

	wp = zeros(n,d+1);
	wp = WPImpulse(wp,d,b,k,qmf);
	w  = wp(:,1)';
//
	pr = w.^2 ./ sum(w.^2);
	t  = 2*%pi .* (0:(n-1)) ./ n;
	x = sum(cos(t) .* pr);
	y = sum(sin(t) .* pr);
	if norm([x y]) < 1.e-6,
		pos = n/2;
	else
		pos = (atan(-y,-x) + %pi) ./ (2*%pi) * n;
	end
	endfunction