2009/11/9 fangming he <fangmin...@hotmail.com>:
> Hi, All,
>
> I cannot understand why the phase accumulator should be limited to
> [-16*pi,16*pi]. Please clarify it for me if you have some ideas on it.
>
> The following is the code in this class:
> if (fabs (d_phase) > 16 * M_PI){
> double ii = trunc (d_phase / (2 * M_PI));
> d_phase = d_phase - (ii * 2 * M_PI);
> }
My guess is that there is still only so much precision in a floating
point number. Knowing you are going to reduce the phase down modulo
2*pi, when dealing with large numbers, the error really starts to
accumulate.
Try it out. Take a phase value and add 2*pi, then reduce that large
number down by 2*pi. How many iterations does it take before you have
a significant error?
This is only a guess and by no means anything else. If someone more
knowledgeable would like to shed some light, please do so.
Brian
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
