[OSM-talk] Invisible waypoints

nick at hogweed.org nick at hogweed.org
Sat Mar 25 20:42:23 GMT 2006


> Some progress: I persuaded osmeditor2 to grab data direct from the
> Geko. I then saved it as .osm format. This produced a few more issues
> to report:
>
> 1)	I had to edit MainWindow2.cpp to set the name of my serial
> 	device. This needs to be read from a config file and/or set in
> 	the GUI.

True --- again one of those little things I've been meaning to do but never 
got round to. Will do for the new version.

> 2)	Having read in a lot of tracks from the GPS, the window was
> 	blank because it had chosen an origin and zoom that did not
> 	include any data points. This was probably made worse by the
> 	fact that the data includes tracks from both the UK and New
> 	Zealand! Interestingly, it was not very far off the NZ tracks
> 	and I was able to scroll across to a known point.

It sets the location to the average of all nodes read in from the .osm file, 
so I'm guessing you have more New Zealand data than UK.

> 3)	When I saved the data in .osm format and read it in again, the
> 	track points were grouped in vertical lines. It looks as if
> 	the save process limits the number of *significant figures*
> 	rather than the number of *decimal places* on lat/long data.
> 	Thus, for places in NZ we get lines like:
>
> 	<node lat='-36.1602' lon='175.355' uid='-12' tags='class=trackpoint;'/>
>
I've never noticed this precision giving me a problem. However I have (just 
now) altered it in the code - the reason why it was 6 significant figures was 
that that is the default value for the QTextStream (Qt output stream). I've 
changed it to 10.

Nick




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