How to denoise raw EEG data with MATLAB?

I made the program which would filter out the noise from raw EEG data, however, I could not implement the code. Could you please tell me what is wrong with this program? The program is down below.
function OutputEEG = MyEEGFilter(InputEEG,fs)
fs=SampleRate;
lowEnd = 3; % Hz
highEnd = 70; % Hz
filterOrder = 2; % Filter order (e.g., 2 for a second-order Butterworth filter). Try other values too
[b, a] = butter(filterOrder, [lowEnd highEnd]/(fs/2)); % Generate filter coefficients
d = designfilt('bandstopiir','FilterOrder',8, ...
'HalfPowerFrequency1',49,'HalfPowerFrequency2',51, ...
'DesignMethod','butter','SampleRate',fs);
InputEEG=double(InputEEG);
Foutput(1,:) = filtfilt(d,InputEEG(1,:));
Foutput(1,:) = filtfilt(b,a,Foutput(1,:));
end

3 Comments

Could you specify what errors you are getting? My first guess would be that your error is "output variable OutputEEG was not assigned"?
I assumed this as OutputEEG was not assigned anywhere (maybe you wanted Foutput to be OutputEEG? If that is the case just change one of the variable names and it should give an output). If you were getting another error or problem. Please specify the problem a bit more
Thank you for answering my question. Yes, your assuming is correct, so I defined OutputEEG like {OutputEEG = Foutput;} in the bottome of my code. But There is an error like {function OutputEEG = MyEEGFilter(InputEEG,fs) ↑ Error: Function definitions are not permitted in this context.}. What should I do next, please? Actually I'm not good at programming such as Matlab.
Did you put your function in a seperate .m file? You cannot call a function straight from the command window, that could be the cause of this new error.

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 Accepted Answer

How are you calling it? And attach InputEEG and fs in a .mat file so we can call it ourselves with your data. And be sure to define OutputEEG. Maybe it's as simple as
OutputEEG = Foutput;
As the last line of your program.

1 Comment

Thank you for answering my question. I corrected the definition of OutputEEG as you pointed out. Also, I tried to attach zip file of my InputEEG data, however, I couldn't send it to you because it exceeds more than 5 MB. Attached is .mat file of EEG information like sample rate.

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on 9 Nov 2018

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on 13 Nov 2018

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