[Loadstone] Show area and checkpoints only

Shawn Kirkpatrick shawn at odyssey.cm.nu
Tue Nov 6 02:05:55 GMT 2007


I'm not sure how many points would fit in ram, it's about 300 bytes per 
point structure plus some overhead I'd guess. There's a lot of calculations 
involved, the distance and angle have to be computed for each point with 
each position change. The angle calculations aren't too bad but the distance 
calculation is a lot of math. The phones don't have a floating point unit so 
it's emulated adding to the computing requirements.
Points in ram are faster than the database, that's why checkpoints are 
stored there. The database is only queried on request, not automatically.

On Mon, 5 Nov 2007, Ari Moisio wrote:

> Hi Shawn
>
>
>  How many points will fit for example 500 kB of RAM?
>
> How long processing delays we are talking about? It will also take time to 
> manually search points and checking them one by one.
>
> Why does points stored in RAM need more computation than points stored in 
> database?  Because points in ram are a subset of points in the database one 
> would expect they are faster to handle.
>
>
>
>
>
> You can still escape from the Gates of hell: Use Linux!
> -- 
> mr. M01510
>
>
> On Mon, 5 Nov 2007, Shawn Kirkpatrick wrote:
>
>> A mass point checking feature could run in to two unexpected problems. The 
>> first is running out of memory. Since you wouldn't know how many results 
>> will be in a given search there's no telling how much memory the list will 
>> need. Some of these phones don't have what you'd call a lot of memory to 
>> work with so this could be a real problem. The second problem would be if 
>> you get the list in to ram then you have to process it with every position 
>> change. That's going to be very computationally expensive and probably 
>> quite slow.
>> 
>> On Mon, 5 Nov 2007, Ari Moisio wrote:
>> 
>>> Hi
>>> 
>>> I agree.  If only checked points are visible when looking for nearest 
>>> points there should be similar behaviour when looking for several nearby 
>>> points.
>>> 
>>> A mass-checkin feature for multiple points at once would be nice too: 
>>> points within given  radius around certain point or points with given 
>>> string in their names.
>>> 
>>> 
>>> You can still escape from the Gates of hell: Use Linux!
>>> -- 
>>> mr. M01510
>>> 
>>> 
>>> On Mon, 5 Nov 2007, Cathomas Jürg wrote:
>>> 
>>>> ;The way it works now allows you to look at the database even if the use 
>>>> ; checkpoints only is active.
>>>> Yes, that's ok and the marked points are indicated, but why not restrict 
>>>> on marked points when "checkpoints only" is active?
>>>> So, you would have a better chance to find the next checkpoinp on your 
>>>> way.
>>>> 
>>>> _______________________________________________
>>>> Loadstone mailing list
>>>> Loadstone at loadstone-gps.com
>>>> http://www.loadstone-gps.com/mailman/listinfo/loadstone
>>> 
>


More information about the Loadstone mailing list