Hi Deepika
You can start off by creating an array of the indices of rising edges of the TTL Pulses. Your code could look something like this
rising_edges = find(diff(trigger > threshold) == 1);
Calculate the start and end indices of each TTL Pulse which will then help you reshape the signal into a matrix.
pulse_starts = rising_edges;
pulse_ends = [rising_edges(2:end)-1; length(trigger)];
num_pulses = length(pulse_starts);
pulse_length = pulse_ends(1) - pulse_starts(1) + 1;
signal_matrix = reshape(signal(pulse_starts(1):pulse_ends(end)), pulse_length, num_pulses)';
Once the signal is in form of a matrix, you can use the ‘mean’ function to calculate average signal of the TTL Pulse and then obtain the mid point by taking the mean of the start and end indices arrays and multiplying this with dt (time between samples)
avg_signal = mean(signal_matrix, 2);
dt = 1/sample_rate;
mid_points = (pulse_starts + pulse_ends)/2 * dt;
Hope this helps
