H = freqwin(name,L,bw);
freqwin(name,L,bw) returns a frequency window name of length L with the mainlobe -6dB (half height) bandwidth bw. It is intended to represent frequency response of a band-pass filter/window with bandwidth bw. The bandwidth is given in frequencies normalized to the Nyquist rate.
The function is not periodically wrapped should it be nonzero outside of the L samples (as opposed to e.g. pgauss).
The following windows can be used in place of name:
| 'gauss' | Gaussian window |
| 'gammatone' | Gammatone window. The default order is 4. Custom order can be set by {'gammatone',order}. |
| 'butterworth' | Butterworth window. The default order is 4. Custom order can be set by {'butterworth',order}. |
freqwin(name,L,bw,fs) does the same as above except bw is expected to be in Hz given sampling frequency fs.
freqwin understands the following key-value pairs and flags at the end of the list of input parameters:
| 'fs',fs | If the sampling frequency fs is specified then the bw is expected to be in Hz. |
| 'shift',s | Shift the window by \(s\) samples. The value can be a fractional number. |
| 'wp' | Output is whole point even. This is the default. It corresponds to a shift of \(s=0\). |
| 'hp' | Output is half point even, as most Matlab filter routines. This corresponds to a shift of \(s=-.5\) |
Additionally, the function accepts flags to normalize the output. Please see the help of setnorm. Default is to use 'peak' normalization.