[mkgmap-dev] Bug report --remove-short-arcs=5 ???

Sat Feb 27 05:25:31 GMT 2010

Garvan & maew wrote:
> Garvan & maew wrote:
>   
>> Mark Burton wrote:
>>   
>>     
>>>> If you zoom in I think the contours and provincial boundaries will show 
>>>> up, but at full zoom nothing shows because the national boundaries are 
>>>> missing. I am not sure exactly when they should show in mapsource, but 
>>>> gpsmapedit tells me they are not in the img file at all.
>>>>     
>>>>       
>>>>         
>>> OK, I think what's happening here is that the file contains a lot of
>>> points that are so close together that the remove-short-arc process
>>> just throws them away and then throws the ways away because they
>>> contain less than 2 points. If you look at the diagnostics you get lots
>>> of lines like:
>>>
>>> 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm:   Way 200 (http://www.openstreetmap.org/browse/way/-2475) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78333&mlon=103.63197&zoom=17) - merging node -187534 into -187526
>>> 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm:   Way 200 (http://www.openstreetmap.org/browse/way/-2478) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78236&mlon=103.65167&zoom=17) - merging node -187581 into -187573
>>> 2010/02/23 14:49:04 INFO (Osm5XmlHandler): cambodia.osm:   Way 700 (http://www.openstreetmap.org/browse/way/-2477) has consecutive nodes with the same coordinates (http://www.openstreetmap.org/?mlat=11.78327&mlon=103.34835&zoom=17) - merging node -187572 into -187564
>>>
>>> and then later you get:
>>>
>>> 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm:   Way 100 (http://www.openstreetmap.org/browse/way/-11092) has less than 2 points - deleting it
>>> 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm:   Way 200 (http://www.openstreetmap.org/browse/way/-11091) has less than 2 points - deleting it
>>> 2010/02/23 14:49:09 INFO (Osm5XmlHandler): cambodia.osm:   Way 100 (http://www.openstreetmap.org/browse/way/-11094) has less than 2 points - deleting it
>>>
>>> Can you reduce the number of points in the ways?
>>>
>>> Mark
>>>
>>>   
>>>     
>>>       
>> Reducing the number of points sounds like a good idea and I have read of 
>> tools that do this. The import is from shapefiles originally, so I think 
>> I can manage this.
>>
>> But why do the national boundaries display correctly when I delete the 
>> contour lines? Something is wrong. The line that is being dropped is a 
>> single line with 22,668 points.
>>
>> Garvan
>>   
>>     
> PS. Thanks for your help.
>   
I found a generalize function in gpsmapedit that removed 10% of the 
points in the file, but the national boundaries still did not display, 
so I split the very long polyline up and then it compiled correctly. 
This experience may be worth noting for others who see long lines 
disappearing with no error message when compiling in osm format.

Thanks, Garvan