Re: [Discuss-gnuradio] math range error?

[Eric Blossom]

On Tue, Feb 21, 2006 at 05:12:06PM +0100, Martin Dvh wrote:
> Eric Blossom wrote:
> > On Mon, Feb 20, 2006 at 01:09:17PM -0800, joe j wrote:
> > 
> > You're probably trying to plot some NaN's or Inf's.  Not sure where
> > they might come from (division?).  On the other hand, if what you're
> > trying to get is the angle, just run the output the multiplier into
> > gr.complex_to_arg().  No need for mag or div.

> I also had a lot of these when I was doing things like this.
> I think it has the same cause as why the scopesink autoscaling started at 
> +1e31 many times.
> For some reason the first few samples of usrp_source_c sometimes has strange 
> values (very big, Nan, inf)
> I don't know if it is some uninitialized buffer or something else.

Martin (or anybody else), I tried to reproduce this earlier today and
was unable to.  Can you come up with a small reproducible test case
that demonstrates the problem?  If it's usrp_oscope, you'll need to edit
the file to change the default scaling from a fixed range to
autoscaling.  Do that by changing 1000 to None in this line:

        parser.add_option("-v", "--v-scale", type="eng_float", default=1000,
                          help="set oscope initial V/div to SCALE 
[default=%default]")

Please be sure to reproduce the problem using the current CVS code.

Thanks,
Eric