Hi I am trying to use a low pass filter in Matlab. I am trying to use the simple butterworth filter.
I have defined dataset say "data". Then I created the butterworth filter as follows:
Butterworth design require the user to give N and Wn. I used N as 2 and Wn as 0.01. Here, I randomly chose the value of Wn to 0.01.
My data is a hourly data and I want to apply 48 hour low pass filter. What would be the cut off frequency in my case ?
After that I used the following code to design a filter:
The filtered data looks good but I want to know what cutoff frequency should I use.