finding accurate number of peaks and eleminate unwanted peaks

Question

sarmad m 2017-3-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/330881-finding-accurate-number-of-peaks-and-eleminate-unwanted-peaks

编辑： Greg Dionne 2017-3-22

在 MATLAB Online 中打开

HI

I'm trying to find peaks in this data :

the actual data has 10 peaks as shown in the image below (peaks are in rectangle)

. I applied sgf filter got the peaks below

     order = 7;
     framelen =15;
     x=data;
     lx = 34;
     sgf = sgolayfilt(x,order,framelen);
    plot(x);
    hold on;
   plot(sgf);
   sgf=-sgf;
   [pks_smoothed,locs_smoothed,widths_smoothed,proms_smoothed] = findpeaks(sgf,'MinPeakProminence',0.05);
   pks_smoothed = -pks_smoothed;
   plot(locs_smoothed,pks_smoothed,'g*');
   text(locs_smoothed+.02,pks_smoothed,num2str((1:numel(pks_smoothed))'))

it detects many unwanted peaks how can I find the required peaks accurately and get rid of unwanted peaks ?

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Adam 2017-3-20

That seems like a very small MinPeakProminence value

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Greg Dionne 2017-3-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/330881-finding-accurate-number-of-peaks-and-eleminate-unwanted-peaks#answer_259548

在 MATLAB Online 中打开

Try:

findpeaks(sgf,'MinPeakProminence',1.2);

3 个评论
显示 1更早的评论隐藏 1更早的评论

Adam 2017-3-21

编辑：Adam 2017-3-21

Well, you can just set the 'NPeaks' property to 10, but whether it picks the 10 you want or not is another matter. You may still have to tweak around with some of the other options for findpeaks.

Greg Dionne 2017-3-22

编辑：Greg Dionne 2017-3-22

An alternative is to perhaps take the output of your widths_smoothed and prom_smoothed and come up with some heuristic that matches the most of the peaks you care about then filter out the rest based upon that somehow. Some of your peaks look kind of "flat". Maybe use a combination of medfilt1() and diff() to identify the edges.

请先登录，再进行评论。