plot regression line through first 5 peaks

I am trying to plot the first 5 peaks on the PSD and I am having trouble getting the peaks to plot in their correpsonding locations. I was wondering how to go about this.

 [maxpks, maxloc]=findpeaks(PSD);
 [s,t]=size(maxloc);
figure(1)
plot(fp,PSD)
hold on
fpml=fp(maxloc);
plot(fpml, maxpks, 'r*')
hold on
sortpks=sort(maxpks);
sortlocs=sort(maxloc,'descend');
[j,h]=size(sortpks);
J= [sortpks(j),sortpks(j-1),sortpks(j-2), sortpks(j-3), sortpks(j-4)]; %first five peak 
ML=[sortlocs(j),sortlocs(j-1),sortlocs(j-2),sortlocs(j-3),sortlocs(j-4)];
ML=[maxloc(s-4),maxloc(s-3),maxloc(s-2),maxloc(s-1),maxloc(s)]

plot(J,'y*')
 Fit = polyfit(ML,J,1); %linear regression 
 yfit = Fit(1)*ML+Fit(2); %equation of line 
 hold on
 plot(ML,yfit,'g-')
 hold off

Answer 1

[Mathieu NOE]

hello

you can directly ask findpeaks to search only the 5 largest peaks :

[...] = findpeaks(...,'NPeaks',NP) specifies the maximum number of peaks

to be found. NP is an integer greater than zero. If not specified, all

peaks are returned. Use this parameter in conjunction with setting the

sort direction to 'descend' to return the NP largest peaks. (see

'SortStr')

[Ashlyn McCann]

So this find the first 5 peaks but not the first 5 largest . I drew 5 blue marks from the peaks I need to pick out.

[Mathieu NOE]

try with following sorting options

[peaks,locs] = findpeaks('NPeaks',5,'SortStr','descend');

[Ashlyn McCann]

It worked! Thank you!

[Mathieu NOE]

My pleasure !