# What is the meaning of "width" and "prominences" in findpeaks

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It said that:

[pks,locs,w,p] = findpeaks(data) additionally returns the widths of the peaks as the vector w and the prominences of the peaks as the vector p.

w is the widths of the peaks as the vector w

I still unable to find out how they calculate the width.

In the example below:

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);

end

PeakSig = sum(Gauss);

Plot the individual curves and their sum

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

grid

findpeaks(PeakSig,x,'MinPeakProminence',2,'Annotate','extents','WidthReference','halfheight')

[pks,locs,w,p]= findpeaks(PeakSig,x,'MinPeakProminence', 2,'Annotate','extents','WidthReference','halfheight')

title('Signal Peak Widths')

w =

0.2352 0.1725

p =

4.8721 3.0028

Is the w is the width (half-height) and p is height as pointed in the plot?

##### 0 Comments

### Accepted Answer

Star Strider
on 7 Feb 2019

Is the w is the width (half-height) and p is height as pointed in the plot?

Your interpretation of ‘p’ is correct. The value of ‘w’ returned depends on how you define 'WidthReference' (link). You can define it to be full width half maximum (FWHM) if you define it as 'halfheight'.

##### 5 Comments

Duy Tran
on 12 Jul 2021

is it possible to get the endpoints (data points) of the widths apart from the distance?

Star Strider
on 12 Jul 2021

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