peak width calculation methods
显示 更早的评论
Hi
I'm calculating peak width using half-prominence method . For the peak in the rectangle is there is a method to make the horizontal line the finds the widths to shift up or make vertical line like this image
? . I tried both methods for peak width detection (half-width, half-prominence ) but it gave me the same results .
Half-prominence
close all
order =9 ;
framelen =15;
lx = 20;
% generate sinal
x = 1:1:1432;
y = (AV)';
y = sgolayfilt(y,order,framelen);
% get derivatives
dy = diff(y);
dx = diff(x);
dy_dx = [0 dy./dx];
findpeaks(y,x,'Annotate','extents','MinPeakProminence',0.006);
% get peaks with width computed by 'findpeaks'
[pks,locs,peakWidth1,p] = findpeaks(y,x,'MinPeakProminence',0.006);
half-height :
order =7 ;
framelen =11;
x=-AV;
lx = 20;
sgf = sgolayfilt(x,order,framelen);
hold on;
sgf= 0.02-sgf;
findpeaks(sgf,'MinPeakProminence',0.004,'WidthReference','halfheight','Annotate','extents');
[pks,locs,widths,proms]=findpeaks(sgf,'MinPeakProminence',0.004,'WidthReference','halfheight');
pks = -pks;
plot(locs,pks,'g*');
text(locs+.02,pks,num2str((1:numel(pks))'));
采纳的回答
Greg Dionne
2017-4-14
It seems you are interested in the relative height of the spike with its immediate vicinity (not with respect to higher peaks). To do that, try subtracting off the results of a lowpass or median filter first.
findpeaks(sgf - medfilt1(sgf,21), ...)
更多回答（2 个）
Matlaber
2019-1-14
1 个投票
I still cannot get the meaning how the width being calculated.
3 个评论
lakshman s
2020-5-9
Is there a way to calculate the endpoints of the width?
Matlaber
2020-5-9
I am asking that too.
Christian
2020-6-23
Me too...
I have added median filter, and tested this data below.
and I got these widths values using this code :
close all
% plot default annotated peaks
subplot(2,1,1);
order =11 ;
framelen =15;
lx = 20;
% generate sinal
x = 1:1:1432;
y = -(Averages)';
y = sgolayfilt(y,order,framelen);
% get derivatives
dy = diff(y);
dx = diff(x);
dy_dx = [0 dy./dx];
%plot(x);
findpeaks(y - medfilt1(y,50),x,'Annotate','extents','MinPeakProminence',0.003);
% get peaks with width computed by 'findpeaks'
[pks,locs,peakWidth1,p] = findpeaks(y,x,'MinPeakProminence',0.003);
subplot(212);
plot(x,y);
My problem is with peak number 6 width which is= 24 ?, I think it calculates the width at the start and end edges .
1 个评论
Greg Dionne
2017-4-27
looks like you forgot the medfilt1 in the second call to findpeaks.
You may also try using 'WidthReference' 'halfheight' if you're after FWHM values once you've removed the baseline.
load data.csv
close all
% plot default annotated peaks
order =11 ;
framelen =15;
% generate sinal
y = -(data)';
y = sgolayfilt(y,order,framelen);
%plot(x);
findpeaks(y - medfilt1(y,50),'Annotate','extents','MinPeakProminence',0.003);
% get peaks with width computed by 'findpeaks'
[pks,locs,peakWidth1,p] = findpeaks(y - medfilt1(y,50),'MinPeakProminence',0.003);
类别
在 帮助中心 和 File Exchange 中查找有关 Descriptive Statistics 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
