Re: [Discuss-gnuradio] vector sink data

[Ben Reynwar]

On Thu, Aug 9, 2012 at 1:53 PM, abdullah unutmaz
<address@hidden> wrote:
> Greetings,
>
> I would like to ask you how to read the data stored in a vector sink. I
> tried the solutions I found in the discussion list. You can see some part of
> my python code below.
> ------------------------------------------------------------------------------------------------------------------------------------------------------
> ##################################################
>             # Connections
>             ##################################################
>             self.connect((self.my_vec_src, 0), (self.my_thro, 0))
> vector_source -> throttle
>             self.connect((self.my_thro, 0), (self.my_h, 0))
> throttle -> head
>             self.connect((self.my_h, 0), (self.my_vec_snk, 0))    head ->
> vector_sink
>
>             time.sleep(10)
>             my_data=self.my_vec_snk.data()
>             print "data: ",my_data
> --------------------------------------------------------------------------------------------------------------------------------------------------------
> if __name__ == '__main__':
>     parser = OptionParser(option_class=eng_option, usage="%prog: [options]")
>     (options, args) = parser.parse_args()
>     tb = top_block()
>     tb.Run(True)
> ----------------------------------------------------------------------------------------------------------------------------------------------------------
> Output of the program :
>
> data:  ()
>
> I need to read an incoming data to correlate with some predefined data,
> vector. If I am not wrong the best solution is to save data in a vector sink
> same length as the predefined vector, then applying the cross-correlation to
> them. The program above is just a test program to examine what the vector
> sink
> stores, but I am confused why it does not work, because I saw a similar
> working use of a vector sink with USRPs. I already save the data in a file,
> but it does not seem to me as a good solution at least due to possible
> memory waste, though clearing the file is possible in run-time.
>
> Thanks in advance,
> Abdullah
>
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> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>

vector_sink is useful if you're running for a short time, for example
in a test.  You can access that data using snk.data() after tb.run()
has completed.
So something like:
   tb.run()
   time.sleep(10)
   my_data = tb.my_vec_snk.data()
   print "data: ",my_data

To extract data from a running flow graph use the probe blocks
(gr.probe_signal_*).
   tb.start()
   time.sleep(10)
   my_data = tb.my_probe_signal.level()
   print "data: ",my_data