help with FiltFilt and entering coeff

Is there a video on how to enter filter coeff, I have these calculated but not sure how I enter them. I have calculated my Xabs but don't know how to to filter the signal using:

a(1)*y(n) = b(1)*x(n) + b(2)*x(n-1) + ... + b(nb+1)*x(n-nb) - a(2)*y(n-1) - ... - a(na+1)*y(n-na) a(1)*y(n) = b(1)*x(n) + b(2)*x(n-1) + ... + b(nb+1)*x(n-nb)

I don't want to use toolbox.

Thanks

Answer 1

[Abhishek Ballaney]

https://in.mathworks.com/help/signal/ref/filtfilt.html

[David Ballantine]

That’s not what I was looking for.

I have calculated the coeff of both a and b, I have 2 terms in A and 3 terms in B but I don’t know how to use these when using the filter(b,a, X).

Thanks

[Osman Atay Öztürk]

change the order of filter probably you used first order butterworth filter thats why you have 2 terms in A and B.

[b,a] = butter(N,Wn,'high');

Change N for changing order of butter filter.