« Return to Thread: GRC noise source seems to give same output regardless of seed

Re: GRC noise source seems to give same output regardless of seed

by Tom Rondeau-2 :: Rate this Message:

| View in Thread

On Fri, Mar 9, 2012 at 3:53 PM, Damian Bevan <deebs67@...> wrote:
Hi Folks,

I am using two 'Noise Source' blocks (Noise-Type: Gaussian, Output Type: complex) in GNU Radio Companion (GRC). I would like the two sets of outputs to be (ideally) independent on a sample-by-sample basis, and to that end I have set the seeds of the two blocks to different values, namely 42 and 99. However, for some reason the outputs of the two blocks seem to be identical. Am I doing something wrong here (most likely), or this a bug?

I'm using GRC version 'GNU Radio Companion 3.5.1git-24-g6333ad78'. I can provide more version info and a copy of the .grc and .py files if necessary (they are pretty simple).

Thanks in advance for any help or advice.

Cheers,

Damian

Try using a negative seed.

I remember this being an issue before that we probably didn't fix (it's a result of the algorithm used to generate the random values, so it's not something to be 'fixed'). Let me know if this works. If nothing else, it really needs to be in the documentation.

Tom
 

_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@...
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

 « Return to Thread: GRC noise source seems to give same output regardless of seed