# finding several values close to the set point

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Caroline on 18 Mar 2020
Commented: Ameer Hamza on 18 Mar 2020
Hello!
I would like to calculate the period in a curve using the mean. However, my attempts to date have not been successful, and I think there is a simple way to do it.
I put random data - eventually I will have a lot of different data and this is to be the method for determining it.
I managed to find the closest value, but unfortunately 1, and I need a few of them to determine the curve's symmetry axis.
Edit: It doesn't search for peaks, because the data on which I work has a few of them on the main peaks, and filtration changes the shape of the plot very much.
A=[1.5 2.3 3.7 4.6 5.3 4.2 3.8 2.7 1.3 2.6 3.9 4.8 6.1 5.3 4.3 3.6 2.8 1.6 2.4 3.6 4.7 5.4 4.0 2.8 1.5 2.7 3.8 4.7];
A=A';
s = size(A);
t = 1:1:s(1);
plot (t,A)
a = mean(A);
Edit2:
In the attachment I add the real data I work on. From each cell I choose 1 column as X and 3 columns as Y in plot (X, Y).

Ameer Hamza on 18 Mar 2020
The following code works by detecting the peak of each cycle and then calculate the average distance between each peak
A=[1.5 2.3 3.7 4.6 5.3 4.2 3.8 2.7 1.3 2.6 3.9 4.8 6.1 5.3 4.3 3.6 2.8 1.6 2.4 3.6 4.7 5.4 4.0 2.8 1.5 2.7 3.8 4.7];
A=A';
t = 1:1:size(A,1);
plot(t,A);
[~, index_peaks] = findpeaks(A);
t_peaks = t(index_peaks);
period = mean(diff(t_peaks));
Ameer Hamza on 18 Mar 2020
Yes, that can be issue, but since you are taking the average of each interval so this difference is somewhat compensated.