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

[Thomas Schönhütl]

Sascha Silbe wrote:
> 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

Hi all,

it was not possible for me to go to bed without a short test of the new 
feature, given by Sascha.

Here my first impressions:

- I attached the files way-test.txt and way-test.dsc which I created via 
www.mapquest.de and my bash script
- this route was my testing route (short distances between waypoints, 
long distances, 30-km/h-zones, highway)
- the first run I did with this ROUTEREACH definition: #define 
ROUTEREACH 
(((1/600)*groundspeed*groundspeed+(1/20)*groundspeed+(25/3))*groundspeed/(3600*milesconv)) 

- I was disappointed, because the speechoutput was nearby the waypoints, 
sometimes only 20 meters before the waypoint was reached
- I think that the Libretto (266 MHz Pentium MMX, 64 MB RAM, running 
GpsDrive, X-Server and festival soundserver) is at the maximum of CPU 
and MEM usage while calculation the ROUTEREACH definition
- I think too that some seconds move until the Libretto is able to 
display the banner with the information and to play the speechoutput via 
festival
- and during all these processes the next waypoint comes nearer and nearer
- I tried a second run with this modified ROUTEREACH definition: #define 
ROUTEREACH 
(((1/600)*groundspeed*groundspeed+(1/20)*groundspeed+(25/3))*groundspeed/(3600*milesconv))*2 

- I doubled the ROUTEREACH and recompiled gpsdrive
- then I did the same run and now the result was nearly PERFECT!!!
- the distance to the next waypoint was great enough to drive in a 
secure way without problems and to have the information how to drive at 
the next waypoint
- only one fact could be better: at the highway with 100 km/h the 
distance to the next waypoint could be greater (now about 300 m, 500 m 
and up to 800 m with higher speed would be ideal and great)
- for my useage with the Libretto the current situation is GREAT and for 
me PERFECT!
- someone with a more "powered" hardware should be able to verify the 
situation if the first definition is ok with better hardware or if it 
should be changed too.

@ Sascha: Could you give me please another definition to have greater 
distances at speeds over 100 km/h (the lower speeds 30-70/80 are ok)!?

This would be GREAT!!!

Thank you very much and a nice weekend,

Thomas.

http:/home.arcor.de/pilleus.pulcher.dsl/homepage

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