[GRASSLIST:3032] Re: v.extract without centroids

[Radim Blazek]

On Thursday 25 March 2004 13:36, Otto Dassau wrote:
> Dear list,
>
> I have two questions:
>
> 1) I imported an area shape with 6000 polygons in g57 and
> there are 2 centroids missing. How can I find these two
> centroids?

I believe that those 2 areas without centroids are slivers between 
shape polygons. 

> 2) I used v.extract on this shape (with the 2 missing centroids).
> v.extract in=SHAPE out=SHAPE2 type=area where='AREAQM>1'.

Try type=area,centroid. This is not correct and it should be fixed,
type=area must export also centroids.

Radim


> The areas geometry is extracted correctly but now all without centroid.
> Is this because there were 2 missing in the beginning?
>
> SHAPE
> Number of nodes     :   12171
> Number of primitives:   15470
> Number of points    :   0
> Number of lines     :   0
> Number of boundaries:   10777
> Number of centroids :   4693
> Number of areas     :   4695
> Number of isles     :   1396
> Number of areas without centroid :   2
>
> SHAPE2 after using v.extract:
> Number of nodes     :   6602
> Number of primitives:   7529
> Number of points    :   0
> Number of lines     :   0
> Number of boundaries:   7529
> Number of centroids :   0
> Number of areas     :   2300
> Number of isles     :   1373
> Number of areas without centroid :   2300
>
>
>  thanks for help
>   Otto