N=length(m);

for i=1:N-1 ;

q(i,1)=m(i,1); 

end;

d=q';

s1=d;

change=1000;

[c,l] = wavedec(d,3,'db4');

%提取小波分解后的低频系数

ca3=appcoef(c,l,'db4',3);

%提取各层小波分解后的高频系数

cd3=detcoef(c,l,3);

cd2=detcoef(c,l,2);

cd1=detcoef(c,l,1);

%对信号强制消噪

cdd3=zeros(1,length(cd3));%第三层高频系数cd3全置0

cdd2=zeros(1,length(cd2));%第二层高频系数cd2全置0

cdd1=zeros(1,length(cd1));%第一层高频系数cd1全置0

c1=[ca3,cdd3,cdd2,cdd1];%构建新的系数矩阵

s2=waverec(c1,l,'db4')%分解新的结构

%[thr,sorh,keepapp]=ddencmp('den','wv',d);

%s2=wdencmp('gbl',c,l,'db4',4,thr,sorh,keepapp);

%subplot(413)

%plot(1:change,s2(1:change));

%title('默认软阈值消噪后信号')

figure(1)

subplot(9,2,1)

plot(1:change,s1(1:change))

title('原始信号')

ylabel('S1')

subplot(9,2,2)

plot(1:change,s2(1:change))

title('强制消噪后信号')

ylabel('S2')

wpt=wpdec(s1,3,'db1','shannon');

%plot(wpt);

%重构第三层8个节点小波系数

s130=wprcoef(wpt,[3,0]);

s131=wprcoef(wpt,[3,1]);

s132=wprcoef(wpt,[3,2]);

s133=wprcoef(wpt,[3,3]);

s134=wprcoef(wpt,[3,4]);

s135=wprcoef(wpt,[3,5]);

s136=wprcoef(wpt,[3,6]);

s137=wprcoef(wpt,[3,7]);

%计算第三层8个节点小波能量

s10=norm(s130);

s11=norm(s131);

s12=norm(s132);

s13=norm(s133);

s14=norm(s134);

s15=norm(s135);

s16=norm(s136);

s17=norm(s137);

%计算方差

st10=std(s130);

st11=std(s131);

st12=std(s132);

st13=std(s133);

st14=std(s134);

st15=std(s135);

st16=std(s136);

st17=std(s137);

disp('正常信号的特征向量');

snorm1=[s10,s11,s12,s13,s14,s15,s16,s17];

std1=[st10,st11,st12,st13,st14,st15,st16,st17];

%显示三层个节点小波系数

subplot(9,2,3);plot(1:change,s130(1:change));ylabel('S130');

subplot(9,2,5);plot(1:change,s131(1:change));ylabel('S131');

subplot(9,2,7);plot(1:change,s132(1:change));ylabel('S132');

subplot(9,2,9);plot(1:change,s133(1:change));ylabel('S133');

subplot(9,2,11);plot(1:change,s134(1:change));ylabel('S134');

subplot(9,2,13);plot(1:change,s135(1:change));ylabel('S135');

subplot(9,2,15);plot(1:change,s136(1:change));ylabel('S136');

subplot(9,2,17);plot(1:change,s137(1:change));ylabel('S137');下载本文