Re: freqz issue

[Kai Torben Ohlhus]

On 1/6/20 10:12 PM, Laurent HAAS - F6FVY wrote:
> Hi
> 
> I'm trying to experience basic signal processing with Octave, while the
> original article has been written for Matlab
> 
> http://aaronscher.com/wireless_com_SDR/RTL_SDR_AM_spectrum_demod.html
> 
> I'm actually facing this issue :
> 
> In the "Plot the spectrum" section,
> 
> freqz(y(1:5000),1,[-4E6:.01E6:4E6],2.5E6);
> 
> keeps the spectrum totally blank, and returns this error :
> 
>>> freqz(y(1:5000),1,[-4E6:.01E6:4E6],2.5E6);
> error: __plt2vv__: vector lengths must match
> error: called from
>     __plt__>__plt2vv__ at line 482 column 5
>     __plt__>__plt2__ at line 242 column 14
>     __plt__ at line 107 column 18
>     plot at line 223 column 10
>     freqz_plot at line 55 column 3
>     freqz at line 194 column 5
>>>
> 
> I'm running Octave 5.1.0 under Win7-32 bit
> 
> What am I missing ?
> 
> Thanks and regards
> 


I am a bit lazy to go deep into your issue (not my domain), but a
minimal working example would be

  y = ones (1, 5000);
  freqz(y(1:5000),1,[-4E6:.01E6:4E6],2.5E6);

Thus what is the `y` you are trying to work with?

  [m,n] = size (y)
  min (y)
  max (y)

Which call of `freqz()` [1,2] would you like to use?

HTH,
Kai

[1] https://octave.org/doc/v5.1.0/XREFfreqz.html
[2] https://www.mathworks.com/help/signal/ref/freqz.html