[GRASS-user] Convert vector map from line to boundary/area

Moritz Lennert mlennert at club.worldonline.be
Fri Apr 7 00:45:00 PDT 2017


On 07/04/17 00:57, Rich Shepard wrote:
>    I have done something incorrectly trying to create a mask and need a
> clue-stick to correct the situation. Here's what I did:
>
>    1. Digitized a line to define an area on a base raster map; saved it as
>  	anal_area_mask.
>
>    2. v.to.rast in=bndy_conditions type=area out=anal_area_mask use=cat
>
>    3. Removed existing mask: r.mask -r
>
>    4. Created new mask: r.mask rast=anal_area_mask
>
>    5. Selected a raster map in the Layer Manager window.
>
>    6. No map displayed in the Map Display window; it's plain white.
>
>    Did editing the digitized line to an area, and saving it as a line, affect
> how it was converted to a raster map? Yep.
>
>    If I change the vector map type from line to boundary or area it is not
> visible.
>
>    How do I convert this vector line to either a boundary or area (whichever
> is appropriate) so it produces a raster mask?

1) Convert the line from type line to type boundary (v.type).
2) Add a centroid inside the area (v.centroids)

Moritz


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