Hello All,
Attempting to sign in using a username I made a long time ago I seem to
have
forgotten my password, I then attempted the password reset, followed all
the
steps and attempted to login, still says my username / password is wrong
though. Weird.
Anyway, I was attempting to raise an issue on a documentation error in
gr_firdes, in the .h file it has (notice that it states center of
transition
band for the cuttoff freq):
/*!
- \brief use “window method” to design a low-pass FIR filter
- \p gain: overall gain of filter (typically 1.0)
- \p sampling_freq: sampling freq (Hz)
- \p cutoff_freq: center of transition band (Hz)
- \p transition_width: width of transition band (Hz).
- \p attenuation_dB required stopband attenuation
- The normalized width of the transition
- band and the required stop band
-
attenuation is what sets the number of
taps
- required. Narrow --> more taps
-
More attenuatin --> more taps - \p window_type: What kind of window to use. Determines
- maximum attenuation and passband ripple.
- \p beta: parameter for Kaiser window
*/
static std::vector
low_pass_2 (double gain,
Now in the .c file:
vector
gr_firdes::low_pass_2(double gain,
double sampling_freq, // Hz
double cutoff_freq, // Hz BEGINNING of transition band
double transition_width, // Hz width of transition band
double attenuation_dB, // attenuation dB
win_type window_type,
double beta) // used only with Kaiser
{
Can’t say I know alot about filter design so I have no idea which way it
should be.
Thank you,
Kieran