%裝載原始信號并圖示之
load noismima;
s=noismima(1:1000);
subplot(2,2,1);
plot(s);
title('原始信號');
%==============================
%采用默認閾值、用wdencmp函數進行消噪處理
[thr,sorh,keepapp,crit]=ddencmp('den','wp',s);
%==============================
%用全局閾值選項進行消噪處理
[c,treed,perf0,perfl2]=...
    wpdencmp(s,sorh,3,'db2',crit,thr,keepapp);
subplot(2,2,3);
plot(c);
title('默認閾值消噪信號');
%==============================
%根據前面的消噪效果，調節閾值大小進行消噪
thr=thr+15;
[c1,treed,perf0,perfl2]=...
    wpdencmp(s,sorh,3,'db2',crit,thr,keepapp);
subplot(2,2,4);
plot(c1);
title('調節閾值后的消噪信號');