Matlab - applying low-pass filter to a vector?

If I have a simple low-pass filter, e.g.

filt = fir1(20, 0.2);

and a matrix with a list of numbers (a signal), e.g. [0.1, -0.2,开发者_高级运维 0.3, -0.4] etc, how do I actually apply the filter I've created to this signal?

Seems like a simple question but I've been stuck for hours. Do I need to manually calculate it from the filter coefficients?

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Here you go:

filter(filt, 1, mysignal);

will do the trick. Since this is an FIR filter, the A parameter (the second parameter) is set to 1.

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The filter function is what you need.

I believe help filter or doc filter will get you on your way.

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Here you cant give a value which is grater than 1 for the first argument of fir1 function. It should be between 0 and 1. Let's say cutoff frequency is Fc and sampling frequency is Fs, then if we take Wn as the first argument which is the cutoff frequency as a normalized value. This is how Wn should be calculated.

     Wn = (2/Fs)*Fc

Then you can apply filter function like below:

      filt = fir1(Wn , 0.2);
      filter(filt, 1, mysignal);