# How to fix jump signal?

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Tyann Hardyn on 12 Apr 2022
Commented: Star Strider on 13 Apr 2022
Hi, Community
I have a problem to handle jump noise like this :
My question is simple... How to make the jumped harmonic signals to become linear again according to previous signals? for example like this signal below :
Is kinda difficult to fix it without a manual remove.. Thank you so much, everyone....

Star Strider on 13 Apr 2022
One approach —
Fs = 256;
t = linspace(0, Fs*10-1, Fs)/Fs;
s1 = randn(size(t))*0.5; % Create Original Signal
ov = 10*(t>2 & t < 5) + 5*(t>=5 & t < 7) + 10*(t>=7);
s2 = s1 + ov; % Create Signal With Step Discontinuities
figure
plot(t, s2)
grid
TF = ischange(s2, 'mean', 'Threshold',5); % Find Abrupt Changes
iscidx = find(TF); % Numeric Indices
iscidxa = [1 iscidx numel(t)]; % Augment 'iscidx'
s2r = zeros(size(t)); % Recovered Original Signal
for k = 1:numel(iscidxa)-1
idxrng = iscidxa(k) : iscidxa(k+1);
s2r(idxrng) = s2(idxrng) - mean(s2(idxrng)); % Detrend Step discontinuities
end
% s2r = filloutliers(s2r,'linear'); % Remove Any Remaining 'Spikes' (If Necessary)
figure
plot(t, s2r)
hold on
plot(t, s1, '--')
hold off
grid
legend('Detrended Signal','Original Signal', 'Location','best')
See the documentation for ischange for details on it.
It will be necessary for you to test it with your signal.
.
##### 2 CommentsShowHide 1 older comment
Star Strider on 13 Apr 2022
As always, my pleasure!
The NaN values are considered by MATLAB to be ‘missing’, so remove them with rmmissing (that removes all the values that correspond to any missing value) or fillmissing to interpolate the missing values.

Walter Roberson on 13 Apr 2022
Perhaps do a movmean() and subtract that from the signal ?
Though possibly you might not be happy with the results at the jump boundaries.