Matlab差分阈值法标记小波变换软阈值处理过的脉搏波特征点

clc;
clear;
a=textread('C:\Users\lenovo\Desktop\t.txt','%s')';%以字符形式打开文件
alpha=hex2dec(a)'; %16进制转化为10进制数，存入alpha矩阵 %%%%%%%16进制转10进制 转化方法二%%%%%%%%%%%

[c,l]=wavedec(alpha,3,'db4'); 
a3=appcoef(c,l,'db4',3); 
d3=detcoef(c,l,3); 
d2=detcoef(c,l,2); 
d1=detcoef(c,l,1); 
thr=1; 

%进行软阈值处理 
ytsoftd1=wthresh(d1,'s',thr); 
ytsoftd2=wthresh(d2,'s',thr); 
ytsoftd3=wthresh(d3,'s',thr); 
c3=[a3 ytsoftd3 ytsoftd2 ytsoftd1]; 
s4=waverec(c3,l,'db4'); 
data1=diff(s4);%一阶微分
data2=diff(data1);%二阶微分

[maxs,index]=max(data1);
F=0.8*maxs;
x=find(data1>F);
v=1;
while v<length(x)
   if x(v)-x(v+1)>-5&x(v)-x(v+1)<5
       x(v+1)=[]
   else
       v=v+1;