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Re: Signal smoothing

 From: Doug Stewart Subject: Re: Signal smoothing Date: Wed, 30 Dec 2020 05:55:20 -0500

On Wed, Dec 30, 2020 at 1:42 AM Blaz <blaz.pirnat@gmail.com> wrote:
Hello again

This time I have a problem of signal smoothing. I have an input signal (x)
which I import from a .cvs file. It is in principle the combination of sine
wave with added exponential decay. However I would like to smooth the signal
with an exponential function (T is a time constant which is a setting) fro
mlocal tops. These tops are not always the same so simply max (x) does not
work. This is my attempt below, but it does not work properly. Any advise
appreciated.

function [xs] = smooth (t,x,T)

if nargin <3
T =0.064;                    % konstanta za glajenje Stab toka (Siemens
7SS52 Manual, str 94)
end
temp=0;
f=1;
AX=max(x);
m=length(x);
xs=zeros(m,1);
lookback=10;

for i = 1 : m
u(i) = exp(-(t(i))/T);
end
xs(1:lookback) = x(1:lookback);

for j = lookback : m

if AX*u(f) < x(j)
xs(j) = x(j);
f=1;
end

if AX*u(f) > x(j)
xs(j) = AX*u(f);
f++;
end

end

plot(t,x,t,xs)
endfunction

ex.png <https://octave.1599824.n4.nabble.com/file/t373917/ex.png

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Sent from: https://octave.1599824.n4.nabble.com/Octave-General-f1599825.html

Are you trying to overcome noise?

--
DAS