How to find corresponding frequencies after viewing amplitude in descending order?

% Sort amplitude values into descending order and get the corresponding frequency
[DescendAmp, sortIdx] = sort(peak_ft, 'descend');  % Sort amplitudes and get sorting indices

% Reorder the frequencies using the sorted indices
DescendFreq = peak_fr(sortIdx);

% Now DescendAmp contains the sorted amplitudes, and DescendFreq contains the corresponding frequencies
% You can plot the results or display them

% Plot the corresponding frequency vs. amplitude in descending order
figure; 
plot(DescendFreq, DescendAmp, 'o-');
xlabel('Frequency (Hz)');
ylabel('Amplitude');
title('Sorted Frequency vs. Amplitude');
grid on;

Explanation of the Changes:

1. Sorting Amplitude and Getting Indices:

   • [DescendAmp, sortIdx] = sort(peak_ft, 'descend');
   • This line sorts the amplitude values in descending order and returns the sorting indices sortIdx, which tell you how to reorder the original data.

2. Reordering the Frequencies:

   • DescendFreq = peak_fr(sortIdx);
   • Using sortIdx, we reorder the frequencies (peak_fr) to match the sorted amplitudes.

3. Plotting the Results:

   • plot(DescendFreq, DescendAmp, 'o-');
   • This line creates a plot showing the sorted frequencies against their corresponding amplitudes.

Output:

• DescendAmp: Amplitudes sorted in descending order.
• DescendFreq: Frequencies corresponding to the sorted amplitudes.

Now, you can directly view the frequencies corresponding to the peaks in descending order of their amplitudes.