Using FInd Peak function but not getting required values

Using my custom find_peak function to locate the highest maximum and lowest minimum values in three Phases. But in last Phase I am not getting the required output even calling all phase with a same function. Secondly getting the 50% decay values that are negative. Kindly guide me what is wrong in my code. I am sharing my script and GUI file and screenshot

Answer 1

[Nipun]

Hi Ehtisham,

I understand that you are having issues with the findpeaks function to locate the highest maximum and lowest minimum values in three phases, and you are encountering problems in the last phase and with 50% decay values. I recommend the following steps to get the expected results:

Highest Maximum and Lowest Minimum Values: Ensure you are correctly identifying peaks and troughs for each phase.

[~, locsMax] = findpeaks(signal, 'MinPeakHeight', threshold);
[~, locsMin] = findpeaks(-signal, 'MinPeakHeight', threshold);
maxValue = max(signal(locsMax));
minValue = min(signal(locsMin));

Handling Multiple Phases: Loop through each phase and apply the findpeaks function.

for phase = 1:numPhases
    currentSignal = phases{phase};  % Assuming phases is a cell array of signals
    [~, locsMax] = findpeaks(currentSignal, 'MinPeakHeight', threshold);
    [~, locsMin] = findpeaks(-currentSignal, 'MinPeakHeight', threshold);
    maxValue = max(currentSignal(locsMax));
    minValue = min(currentSignal(locsMin));
    disp(['Phase ', num2str(phase), ': Max = ', num2str(maxValue), ', Min = ', num2str(minValue)]);
end

50% Decay Values: Ensure you are computing the decay values correctly. If values are negative, adjust your computation accordingly.

halfDecayValue = 0.5 * maxValue;  % Assuming maxValue is positive
decayLocs = find(signal <= halfDecayValue, 1);
if isempty(decayLocs)
    disp('No decay point found');
else
    decayValue = signal(decayLocs);
    disp(['Decay value: ', num2str(decayValue)]);
end

Make sure to verify the phase-specific signals and their thresholds. This should help you identify why the last phase behaves differently.

Hope this helps.

Nipun

[Ehtisham]

I added that but it required a signal toolbox that i do not have suggest me another solution.