查找局部最大值 - MATLAB findpeaks - MathWorks 中国 (2024)

语法 说明 示例 查找向量中的峰值 查找峰值及其位置 峰值相对高差 在设定最小峰间距的条件下查找峰值 约束峰值特征 饱和信号的峰值 确定峰宽 输入参数 data — 输入数据 向量 x — 位置 向量 | datetime 数组 Fs — 采样率 正标量 名称-值参数 NPeaks — 最大峰值数正整数标量 SortStr — 峰值排序 'none' (默认) | 'ascend' | 'descend' MinPeakHeight — 最小峰值高度 -Inf (默认) | 实数标量 MinPeakProminence — 最小峰值相对高差 0 (默认) | 实数标量 Threshold — 最小高度差 0 (默认) | 非负实数标量 MinPeakDistance — 最小峰间距 0 (默认) | 正实数标量 WidthReference — 宽度测量值的参考高度 'halfprom' (默认) | 'halfheight' MinPeakWidth — 最小峰宽 0 (默认) | 正实数标量 MaxPeakWidth — 最大峰宽 Inf (默认) | 正实数标量 Annotate — 绘图样式 'peaks' (默认) | 'extents' 输出参量 pks — 局部最大值 向量 locs — 峰值位置 向量 w — 峰宽 向量 p — 峰值相对高差 向量 详细信息 相对高差 扩展功能 C/C++ 代码生成 使用 MATLAB® Coder™ 生成 C 代码和 C++ 代码。 GPU 数组通过使用 Parallel Computing Toolbox™ 在图形处理单元 (GPU) 上运行来加快代码执行。 版本历史记录 另请参阅 主题 MATLAB 命令 Americas Europe Asia Pacific

data = [25 8 15 5 6 10 10 3 1 20 7];plot(data)

pks = findpeaks(data)

pks = 1×3 15 10 20

findpeaks(data)

x = linspace(0,1,1000);Pos = [1 2 3 5 7 8]/10;Hgt = [3 4 4 2 2 3];Wdt = [2 6 3 3 4 6]/100;for n = 1:length(Pos) Gauss(n,:) = Hgt(n)*exp(-((x - Pos(n))/Wdt(n)).^2);endPeakSig = sum(Gauss);

plot(x,Gauss,'--',x,PeakSig)

[pks,locs] = findpeaks(PeakSig,x);

findpeaks(PeakSig,x)text(locs+.02,pks,num2str((1:numel(pks))'))

[psor,lsor] = findpeaks(PeakSig,x,'SortStr','descend');findpeaks(PeakSig,x)text(lsor+.02,psor,num2str((1:numel(psor))'))

x = linspace(0,1,1000);base = 4*cos(2*pi*x);Pos = [1 2 3 5 7 8]/10;Hgt = [3 7 5 5 4 5];Wdt = [1 3 3 4 2 3]/100;for n = 1:length(Pos) Gauss(n,:) = Hgt(n)*exp(-((x - Pos(n))/Wdt(n)).^2);endPeakSig = sum(Gauss)+base;

plot(x,Gauss,'--',x,PeakSig,x,base)

findpeaks(PeakSig,x,'MinPeakProminence',4,'Annotate','extents')

[pks,locs,widths,proms] = findpeaks(PeakSig,x);widths

widths = 1×6 0.0154 0.0431 0.0377 0.0625 0.0274 0.0409

proms

proms = 1×6 2.6816 5.5773 3.1448 4.4171 2.9191 3.6363

load sunspot.datyear = sunspot(:,1);avSpots = sunspot(:,2);findpeaks(avSpots,year)

findpeaks(avSpots,year,'MinPeakDistance',6)

[pks,locs] = findpeaks(avSpots,year,'MinPeakDistance',6);meanCycle = mean(diff(locs))

meanCycle = 10.9600

ty = datetime(year,3,20);[pk,lk] = findpeaks(avSpots,ty,'MinPeakDistance',years(6));plot(ty,avSpots,lk,pk,'o')

dttmCycle = years(mean(diff(lk)))

dttmCycle = 10.9600

TT = timetable(years(year),avSpots);plot(TT.Time,TT.Variables)

entries = TT(end-4:end,:)

entries=5×1 timetable Time avSpots ________ _______ 1983 yrs 66.6 1984 yrs 45.9 1985 yrs 17.9 1986 yrs 13.4 1987 yrs 29.3 

load mtlbselect = mtlb(1001:1200);

findpeaks(select,Fs,'MinPeakDistance',0.005)

findpeaks(select,Fs,'MinPeakHeight',1)

findpeaks(select,Fs,'Threshold',1)

findpeaks(select,Fs,'MinPeakProminence',1)

rng defaultfs = 1e2;t = 0:1/fs:1-1/fs;s = sin(2*pi*5*t).*sin(2*pi*3*t)+randn(size(t))/10;

bnd = 0.32;s(s>bnd) = bnd;plot(t,s)xlabel('Time (s)')

[pk,lc] = findpeaks(s,t);hold onplot(lc,pk,'x')

[pkt,lct] = findpeaks(s,t,'Threshold',1e-4);plot(lct,pkt,'o','MarkerSize',12)

x = linspace(0,1,1000);Pos = [1 2 3 5 7 8]/10;Hgt = [4 4 2 2 2 3];Wdt = [3 8 4 3 4 6]/100;for n = 1:length(Pos) Gauss(n,:) = Hgt(n)*exp(-((x - Pos(n))/Wdt(n)).^2);endPeakSig = sum(Gauss);

plot(x,Gauss,'--',x,PeakSig)grid

findpeaks(PeakSig,x,'Annotate','extents')

findpeaks(PeakSig,x,'Annotate','extents','WidthReference','halfheight')title('Signal Peak Widths')