Cleaning Shapefiles and creating a coverage

[Dylan Beaudette]

On Nov 27, 2005, at 8:30 PM, David Hunt wrote:

> I want to insure that the external boundary of polygon has its 
> vertices oriented
> clockwise and the vertices of interior voids are oriented 
> counter-clockwise.
> Also the goal is to remove the duplicate edges that are shared among 
> polygons
> because I need the shapefile to be converted into a coverage.
> Basically I want the clean tool to perform the functionality of ESRI's
> CleanShapeFile.exe.
>
> Thanks
> Dave
>
> Quoting Stephen Woodbridge <woodbri at SWOODBRIDGE.COM>:
>
>> Hi Dave,
>>
>> What type of cleaning do you want to do?
>> What do you expect such a utility to do?
>>
>> -Steve
>>
>> David Hunt wrote:
>>> Hello all,
>>>
>>> Does anyone know of a free utility to clean shapefiles?  I am also 
>>> looking
>> for a
>>> utility to take a coverage and convert it into a coverage.
>>>
>>> Thanks for the help.
>>> David
>>> hunt at eecs.orst.edu
>>>
>>
>
>

Dave,

I think what you are referring to is "topological cleaning" of a 
shapefile: i.e. convert a shapefile to an ESRI coverage via building of 
topology.

GRASS can build a topologically correct vector from a shapefile, which 
can then be exported to a variety of formats which can be converted 
into a "Coverage" .

Cheers,


--
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341