Re: [Discuss-gnuradio] Sine wave of only 3 cycles

[Activecat]

Dear Sirs,

But, another problem arisen.

There is a WX GUI Scope Sink in the middle of the flow-graph to plot the instantaneous reading.

When the data stream stop by the Head Block, says, at time=t1, the WX GUI Scope Sink starts to show zero reading.

The question is, how to see the plot between time=0 and time=t1 ?

The workaround is to save the data into a file, then plot it using external tool. This is "off-line" approach.

Is there any "online" approach that doesn't require any external plotting tool, to view the GUI plot between time=0 and time=t1, after the Head Block terminates the data stream?

Regards,

activecat

On Thu, Jan 30, 2014 at 9:47 PM, Activecat <address@hidden> wrote:

Dear Sirs,

Thank you very much.

The "head" block solve my problem precisely.

Note:

The flow graph consists of some other blocks at the middle.

Regards,

activecat.

On Thu, Jan 30, 2014 at 8:18 PM, Marcus Müller <address@hidden> wrote:

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Also,
to do basic mathematical tasks you don't have to rely on GNU Radio,
which is a fine signal processing framework but not so much a math
environment.

If you want to have a three period sine signal, the python is short

#import numpy as np

f_sin = 1.0
f_sample = 16.0
periods = 3.0

s_per_period = f_sample/f_sin

sinevalues = np.sin(np.linspace(0, periods*2*np.pi,
periods*s_per_period) )
sinevalues.astype(np.float32).tofile("filename")

this will be the same data format as written by the file sink.

Greetings
Marcus

On 30.01.2014 13:02, Felix W. wrote:
> Hi,
>
> you can use a Head block to make the sample stream stop after a
> given number of samples. Just calculate how many samples there will
> be in three cycles and set the Head block's parameter accordingly.
>
> Greetings Felix
>
>
> 2014-01-30 Activecat <address@hidden>:
>
>> Dear Sir,
>>
>> A block of Signal Source (Sine) generates sine wave
>> continuously. How to make it just generates 3 wave-cycle and then
>> stop generating immediately. At the end of the flow-graph there
>> is a File Sink. This captures data for offline processing.
>>
>> Regards, address@hidden
>>
>>
>> _______________________________________________ Discuss-gnuradio
>> mailing list address@hidden
>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>>
>>
>
>
>
> _______________________________________________ Discuss-gnuradio
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