Re: [Patch-gnuradio] gr_rotator fix/optimization

[Matt Ettus]

Dan Halperin wrote:
> Two changes:
>
> 1) Default phase increment changed from 1 to 0. This will not cause
> faults and instead do nothing if the rotator phase is not initialized.

Good idea.

> 2) It seems like we can skip (expensive!) normalization of phase vector
> if we simply normalize phase and increment upon setup. I suppose there
> could be some lowest-order-bit precision errors that cause phase to
> degrade over a super-long-running system, but we could surely at least
> replace the current every-time normalization with normalization every K
> calls, for large K (1 million+).

I would keep the normalization -- it's in there because we ran into
cases where the phasor really did decay to zero.  However, I like the
idea of doing it every K times.  Even if K is 100 the performance impact
will be negligible.

Matt

Matt