Re: Are there firls and kaiser filter methods for C++ OOT?

[George Edwards]

Hello Vasil and Marcin,

Thanks very much for your help.

I have all the relevant #include header files and invoke the low_pass filter as follows:

lpfilter = gr::filter::firdes::low_pass(gain, sampling_freq, cutoff_freq, transition_bandwidth,

fft::window::win_type::WIN_HAMMING, beta);

Observations:

Using the mouse to hover over WIN_HAMMING, I can see that it interprets the win_type enum variable and correctly assigns it a value of "0" (which is the value stated in the Gnuradio C++ API Reference manual). However, there is a squidly under beta. Hovering over beta, the error message is: 

Argument of type "double" is incompatible with parameter of type "gr::fft::window::win_type" 

If one of you has a working code fragment using one of the C++ Gnuradio filter methods that you can cut, paste and send in your next email I would appreciate it. 

Thanks for your help.

George

On Tue, Feb 22, 2022 at 6:15 AM Vasil Velichkov <vvvelichkov@gmail.com> wrote:

Hi George,

On 21/02/2022 18.31, George Edwards wrote:
> lpfilter = gr::filter::firdes::low_pass(gain, sampling_freq, cutoff_freq, transition_bandwidth,
> fft::window::win_type <https://www.gnuradio.org/doc/doxygen/classgr_1_1fft_1_1window.html#a599d7e9625d6cc77203a8b877c4911e2>window = fft::window::win_type::WIN_HAMMING, beta = 6.76);
>
> This failed and showed a squidly across the line with fft::window::win_type....!

Try adding "gr::" before "fft::window" and make sure gnuradio/fft/window.h is included.

  #include <gnuradio/fft/window.h>

  lpfilter = gr::filter::firdes::low_pass(gain, sampling_freq, cutoff_freq, transition_bandwidth,
        gr::fft::window::win_type window = fft::window::win_type::WIN_HAMMING, beta = 6.76);

If this does not fix it then provide the exact error you are getting.

Regards,
Vasil