matlab查找极值点

方法1 findpeaks

​t=A;

x=B;

y=detrend(x);

plot(t,y);

grid; hold on

[K,V]=findpeaks(x);

thr=1000;

vdex=find(V>thr);

V1=V(vdex);

K1=K(vdex);

delta=10;if (a(i)<0.5)

a(i)=0;

new(vdex) = 0.5*( y(vdex-delta)+ y(vdex+delta) ) ;

plot(t(K1),V1,'r.','linewidth',5);

title(['信号提取极值,阈值thr=' num2str(thr)]);

方法2 diff

for i=1:3000if (a(i)<0.5)a(i)=0;endend

b=find(diff(sign(diff(a)))<0)+1;% 求解极值点序号plot(t, a,t(b), a(b),'r*') % 画出去噪声后的波形，由于滤波的关系，前一秒钟的信号异常，因此只画1s以后的数据xlabel('t(s)')ylabel('Voltage(v)')axis([1 6 0 2]);title('Final Signal')grid on

方法3 ​localMaximum

a=mydata(:,2);a=detrend(a);

peaks = localMaximum(a,37000);

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