hthr = 2logn^05; eta = sumabsx^2-n1n; crit = lognlog2^15n^05; thr = thselectxrigrsure; thrthr hthr = hthr; threta crit = hthr;根据上述写一个改进的阈值函数的代码

function [thr] = improved_threshold(x) % Compute improved threshold for wavelet denoising n = length(x); hthr = (2*log(n)).^0.5; eta = sum(abs(x).^2-n,1)./n; crit = (log(n)/log(2))^(1.5)/(n.^0.5); thr = thselect(x,'rigrsure'); thr(thr > hthr) = hthr; thr(eta < crit) = hthr; end