Re: [Discuss-gnuradio] gr.fft_vcc usage in make_fft_sink_X

[Eric Blossom]

On Wed, Mar 16, 2005 at 05:34:13PM -0500, cswiger wrote:
> On Wed, 16 Mar 2005, Eric Blossom wrote:
> >
> > serial_to_parallel and parallel_to_serial are format converters.
> >
> > The gr.fft_vcc block requires a vector of complex numbers for its
> > input and produces a vector of complex numbers on its output.
> > serial_to_parallel takes a stream of items and turns them into a
> > stream of vectors.  parallel_to_serial is the inverse.
> >
> 
> Ok - stuff like this runs:
> 
>         src = gr.sig_source_f (sample_rate,gr.GR_SIN_WAVE,440,1,0)
>         s2p = gr.serial_to_parallel (gr.sizeof_float, fft_size)
>         fft = gr.fft_vfc (fft_size,True,True)
>         p2s = gr.parallel_to_serial (gr.sizeof_gr_complex, fft_size)
>         dst = gr.file_sink (gr.sizeof_gr_complex, "fft_test")
> 

This would work fine.  
In this particular case you can reduce this to:

>         src = gr.sig_source_f (sample_rate,gr.GR_SIN_WAVE,440,1,0)
>         s2p = gr.serial_to_parallel (gr.sizeof_float, fft_size)
>         fft = gr.fft_vfc (fft_size,True,True)
>         dst = gr.file_sink (gr.sizeof_gr_complex * fft_size, "fft_test")

> now I just have to get a grasp on what, precisely, it means ;)

Oh, that...

> Appearently there are no(t yet) vector stream operators - such as add,
> multiply ? Python would be too slow...

Stay tuned...  Or better yet, contribute patches ;-) 

They'll be straight-forward extensions of the add, add_const, mult,
mult_const, sub and divide blocks.  Take a look at
gr_complex_to_xxx.{h,cc} to see what I changed to make them apply to
vectors.

> --Chuck

Eric