How to smooth a curve with movmean with consideration of the start and end of an array?

Hello.

I am trying to smooth out a curve with movmean.

My current code looks like this:

Start_i_len = 8;
smooth_offset = cell(Start_i_len, 1);

for i = 1:1:Start_i_len
    smooth_offset{i} = movmean(Offset_itpl_mean{i}, 301);
end

The cell array contains 8 cells, with each consisting of 8192 values. What I want to do is, as it samples 301 values, I want it to connect the beginning and the end of the array (If that makes sense). So that when it smoothes out the values at the nearing the end of the array, it does so with consideration of the values at the start of the array and vice versa. Any ideas on how to do it?

Answer 1

[Matt J]

k=ones(1,301); k(8192)=0;

for i = 1:1:8
    
    tmp=fwd.Offset_itpl_mean{i}(:).';
    
    tmp=ifft(fft(tmp).*fft(k),'symmetric');
    
    fwd.smooth_offset{i} = tmp;
end

[Michael Arvin]

I have tried it, but instead of it being a 1x8192 array, it becomes 8192x8192.

[Matt J]

Try now.

[Michael Arvin]

I tried it and it is now 1x8192, but the values inside are very different from the original values of Offset_itpl_mean{} when I plot it. I did attach a mat file the question for the value of Offset_itpl_mean{}. If you have any other solution to it, I'd greatly appreciate it. Thanks!

[Matt J]

load save1

k=ones(1,301)/301; k(8192)=0; k=circshift(k,-150);

for i = 1:1:8
    
    tmp=Offset_itpl_mean{i}(:).';
    
    tmp=ifft(fft(tmp).*fft(k),'symmetric');
    
    smooth_offset{i} = tmp;
end

plot(Offset_itpl_mean{i}); hold on
plot(smooth_offset{i}); hold off