Filling incomplete data with cftool
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Hello, I've been working with data obtained from body signals, but some data values are NaN so the curve has voids in it, I tried to aproximate the curve with cftool, but I don't know how to fix the data matrix and replace the NaN values. I need to keep the same number of data in the matrix.
Risposta accettata
William Rose
il 28 Set 2021
Modificato: William Rose
il 28 Set 2021
See attached.
%replaceNaNs.m WCRose 20210928
%Replace NaN values in array with interpolated values.
clear;
%Create simulated data
t=0:.001:1;
x=cos(10*pi*t);
%Add NaNs to the data
for i=1:length(x)
if rand<.3, x(i)=NaN; end
end
fprintf('NaNs in x(): %d out of %d\n',sum(isnan(x)),length(x));
%Fix it by interpolation
%1. Determine how many consecutive NaNs at start of array
k1=0;
while isnan(x(k1+1)),k1=k1+1; end
%2. Determine how many consecutive NaNs at end of array
k2=0;
while isnan(x(end-k2)), k2=k2+1; end
%3. Remove beginning and/or end, if they are NaNs.
y=x(1+k1:end-k2);
%4. Replace remaining NaNs by linear interpolation
i=1;
while i<length(y)
if isnan(y(i))
j=1;
while isnan(y(i+j)), j=j+1; end
%Now we know we have j consecutive NaNs, starting at y(i)
%Replace the NaNs by linear interpolation
y(i:i+j-1)=y(i-1)+(1:j)*(y(i+j)-y(i-1))/(j+1);
i=i+j+1;
else
i=i+1;
end
end
fprintf('NaNs in y(): %d out of %d\n',sum(isnan(y)),length(y));
%5. Plot results
figure;
subplot(2,1,1)
plot(t,x,'.b')
subplot(2,1,2)
plot(t(1+k1:end-k2),y,'.r')
Più risposte (1)
Steven Lord
il 27 Set 2021
0 voti
Do you want to remove the NaN values with rmmissing, fill them using fillmissing, or do something else with them (and if so what?)
il 27 Set 2021
il 28 Set 2021
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