How can I put the values of the y-axis in a vector and find the maximum?

This is my MATLAB code:

data=csvread("abc.CSV");

[H, f]=make_fft(data(:,2),data(:,1)); %my function

figure

stem(f,H)

set(gca,'xscale','log')

How can I see values of the plot in a vector? I should find the first and second maximum along the y axis

[Enrico Gambini]

Hello.

I did not fully understand your question. The values of the y-axis are stored inside vector "H", you mean that you want to see a better scale in the y-axis?

[Lorenza Curcio]

if I look for the maximum of H I get the maximum value, but what if I want the second largest value?

Answer 1

[Enrico Gambini]

You mean this?

H_sorted=sort(H); %sort vector "H" in ascending order
idx=find(H==H_sorted(end-1)); %find the index of the second maximum value in vector "H"
2nd_max_value=H(idx); %this is the second maximum value of vector "H"

[Lorenza Curcio]

yes, ty

and how can I display the values ​​of the x axis corresponding to those of the y axis? I mean the full list and not just the maximum

because I want to find which value of the x axis corresponds to the second maximum of the y axis

[Enrico Gambini]

If you want to find the x-axis value of the second maximum y value you can Just:

    x_2ndmax=f(idx)