[GRASS-user] converting lines to polygons

[Micha Silver]

On 28/09/2010 10:00, Markus Metz wrote:

> Micha Silver:
>    
>> Markus Metz wrote:
>>
>>      
>>> Micha Silver wrote:
>>>
>>>        
>>>> In any case, importing polygon shapefiles first as lines (not
>>>> boundaries),
>>>> doing the topology cleanup, and then convert to boundaries and add
>>>> centroids
>>>> seems to be the smoother way to go.
>>>>
>>>>          
>>> I object because
>>>
>>> 1. you would need to replicate the cleaning steps done by v.in.ogr
>>> which has, amongst others, a snapping option
>>>
>>>
>>>        
>> I never noticed that option.
>>      
> http://grass.osgeo.org/grass64/manuals/html64_user/v.in.ogr.html
>    
>> Still, importing unclean shapefile polygons, and correcting the topology is
>> often accompanied by much hair pulling...
>>      
> Unfortunately yes. If data providers would only provide clean data...
>
> I have partially good news: v.in.ogr in 6.4.1 and above is faster and
> produces cleaner and smaller output. Further on, it shows progress
> when cleaning polygons, indicating that something is happening.
> Previously (up to 6.4.0), it went silent for quite some time on larger
> polygon imports which annoyed me considerably, I want to see that
> something is happening.
>
>    
Great, I'm looking forward to seeing the improvements.
> Markus M
>
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>
>
>    


-- 
Micha Silver
http://www.surfaces.co.il/
Arava Development Co.  +972-52-3665918