Re: [Discuss-gnuradio] New random number generator

[Marcus D. Leech]

On 09/02/2015 01:35 PM, Marcus Müller wrote:
> > I'd say we rather want better
> > randomness than faster noise sources
> If that's the case, I'd recommend that Stefan uses the
> normal_distribution variate from boost (Stefan, see my example), rather
> than doing his own "normalization" of the RV, and we use that.
>
> Regarding Boost's mt19937 and the ways Stefan and I make normal
> distributed RV out of the uint32_t that this emits:
>  From getting "raw" uniform uint32_t instead of normal floats through
> boost's normal_distribution(rng) variate is that, to little surprise,
> 75% of time is spent looking up/interpolating/calculating based on the
> uniform integers to normally distributed floats. Blind guess is that
> this would be something that someone who really cares about speed might
> implement in VOLK with sufficient accuracy, making WGN generation
> X3x0-capable.
>
> Cheers,
> Marcus
A call to SHA-256 can return 256 bytes at a time....    Map those bytes 
into {-1.0,1.0}.  That may still not be fast enough, dunno. But the 
distribution
  should be good.