[GRASS-user] Re: [GRASSLIST:1175] add centroids automatically to area boundaries

[Ulrich Leopold]

On Thu, August 10, 2006 15:21, Markus Neteler wrote:
> On Thu, Aug 10, 2006 at 03:04:05PM +0200, Ulrich Leopold wrote:
>> Dear list,
>>
>> I am trying to solve the impossible it seems. I have the following
>> problem:
>>
>> I have a patched vector map with lines. These lines should be converted
>> into area boundaries in order to receive areas. Once boundaries are
>> retrieved I still need  to attach centroids to them in order to overlay
>> with *another* vector map which already consists of boundaries and areas
>> including centroids. How can I achieve this?
>>
>> I tried to convert all lines into boundaries with
>> v.type type=line,boundary
>>
>> It seems to work as there are only boundaries left. Next step would be
>> to add automatically centroids to these boundaries. How can this be
>> done?
>
> Hi,
>
> see v.category for this. I have added a micro FAQ for this:
> http://grass.gdf-hannover.de/wiki/Convert_vector_types

I tried that already but it did not work. It even changes the polygons back to
single lines. But good that you opened a micro FAQ to add the solution later.
Any other ideas?

Ulrich