FIR filter using windowed impulse response
h = window(d,'window',fcnhndl)
h = window(d,win)
h = window(d,'window',fcnhndl) designs an FIR filter using the specifications in filter specification object d. Depending on the specification type of d, the returned filter is either a single-rate digital filter — a dfilt, or a multirate digital filter — an mfilt.
fcnhndl is a handle to a filter design function that returns a window vector, such as the hamming or blackman functions. fcnarg is an optional argument that returns a window. You pass the function to window. Refer to example 1 in the following section to see the function argument used to design the filter.
Construct a lowpass filter specification object of order 10 with a cutoff frequency of 12 kilohertz. We use a sampling frequency of 48 kilohertz. Next we use a function handle to the function Kaiser to provide the window.
d=fdesign.lowpass('n,fc',10,12000,48000); Hd=window(d,'window',@kaiser); fvtool(Hd);