[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] GRC noise source seems to give same output regard

From: Josh Blum
Subject: Re: [Discuss-gnuradio] GRC noise source seems to give same output regardless of seed
Date: Tue, 13 Mar 2012 14:22:00 -0700
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2

looks like channel model too (since it has a noise source)

~/src/gnuradio/grc/blocks$ grep 42 *.xml
gr_channel_model.xml:           <value>42</value>
gr_noise_source_x.xml:          <value>42</value>


On 03/13/2012 08:23 AM, Tom Rondeau wrote:
> On Tue, Mar 13, 2012 at 10:24 AM, Damian Bevan <address@hidden> wrote:
>> Hi Tom,
>> Thanks for the prompt and helpful advice. I have now tried changing the
>> seeds on the two noise blocks to different negative values (-42 and -99),
>> and it does indeed appear to have resolved the problem. Or having one
>> positive (+42) and one negative (-99) also solved the problem.
>> I think you are right that this should be in the documentation. At the
>> moment the documentation is very misleading, in that a) The default seed in
>> the GRC block is 42, which is a great number, but unfortunately is
>> positive, and b) the documentation when you click on the block says
>> "noise_source_c(gr_noise_type_t type, float ampl, long seed = 3021) ->
>> gr_noise_source_c_sptr", which again hints at a positive seed (i.e. of
>> +3021).
>> Cheers, and thanks again.
>> Damian.
> Damian,
> Thanks for getting back to me on this. I'm going to change the
> documentation to explain it.
> And I'm going to change the default values to 0 instead of 42/3201 since
> 0's as good as either of those. I don't want to set it negative, though,
> since that would change the output behavior of the block and someone might
> be relying on this for consistency in their measurements or something.
> Tom
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

reply via email to

[Prev in Thread] Current Thread [Next in Thread]