[ gpsdrive ] No developer question, but a question about an older version of gpsdrive

[Sascha Silbe]

On Sat, Nov 03, 2007 at 04:59:46PM +0100, Thomas Schönhütl wrote:

> /*#define ROUTEREACH (0.02+10*groundspeed/(3600*milesconv))*/
> #define ROUTEREACH1 (10*groundspeed/(3600*milesconv))
> #define ROUTEREACH2 (15*groundspeed/(3600*milesconv))
> #define ROUTEREACH3 (20*groundspeed/(3600*milesconv))
> #define ROUTEREACH4 (30*groundspeed/(3600*milesconv))

Using the lower limits of your speed "zones", I've done a 3-point 
interpolation:

#define ROUTEREACH 
(((1/600)*groundspeed*groundspeed+(1/20)*groundspeed+(25/3))*groundspeed/(3600*milesconv))

Could you test if this works equally well as your discrete approach?
If it doesn't work well at low speeds, could you test this 4-point 
interpolation (using 30 for the first point):

#define ROUTEREACH 
(((1/42000)*groundspeed*groundspeed*groundspeed-(1/280)*groundspeed*groundspeed+(44/105)*groundspeed)*groundspeed/(3600*milesconv))

CU Sascha

-- 
http://sascha.silbe.org/
http://www.infra-silbe.de/
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