How to use filter() if I don't have the transfer function?

I have been provided with an impulse response h (vector of length 3) and an input signal x (vector of length 10).

I need to use the filter() function to perform FIR filtering on the input, but the function requires a transfer function as arguments:

From the documentation:

"y = filter(b,a,x) filters the input data x using a rational transfer function defined by the numerator and denominator coefficients b and a."

How do I get values for a and b so that I can use the function?

Answer 1

[Mathieu NOE]

hello

you have a FIR filter , and in that case the numerator b is equal to the h impulse response coefficients

the denominator a is equal to 1

[Samuel O'Neill]

Thanks, but i'm not sure what you mean about b.

If I have an impulse response of [0.2 0.3 0.2], then what is b?

[Mathieu NOE]

I'm talking about this b and a : "y = filter(b,a,x)

and b = [0.2 0.3 0.2

a = 1