Re: [gpsd-dev] ✘CEP(50) 0.285 metersMime-Version: 1.0

[Gary E. Miller]

Yo Fred!

On Fri, 22 Jul 2016 13:55:52 -0700 (PDT)
Fred Wright <address@hidden> wrote:

> On Fri, 22 Jul 2016, Gary E. Miller wrote:
> 
> > My main attack for a while will we be in geting the numeric
> > precision solid.  Calculating things to about 11 significant
> > decimal digits is harder than it looks.  A 64 bit long is only
> > about 10 decimal digits.  
> 
> Umm, a *64-bit* long is about 19 decimal digits.  Though a double is
> only good for about 15.

And I can't see how to force Python to use a 64-bit long.  Got a clue
for me?

15 from a double is probably close enough, but I would go long double
if I could figure out to get Python to do that.

Do I need to go to NumPy, or something, to force precision in Python?

> > For example, my longitude is 121.314064921W, but a long can only
> > hold 2147483647.  
> 
> Then it must be a 32-bit long.

We aim to have gpsd run on 32 bit and 64 bit systems.  RasPi's, Odroid's
and BBB's currently are 32 bit only.

BTW, John's mailer mungs my UTF-8...

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

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