[GRASS-dev] issue v.to.rast - missing raster labels

Paulo van Breugel p.vanbreugel at gmail.com
Tue Apr 18 01:51:04 PDT 2017


On 18-04-17 09:32, Paulo van Breugel wrote:
> Hi devs,
>
> Converting a vector to raster does in some specific cases yields 
> yields issues with the labeling. E.g., the following (example from NC 
> dataset) results in a layer with each raster cells assigned a category 
> label (the name of the municipality):
>
> v.to.rast input=boundary_municp output=A01 use=attr 
> attribute_column=OBJECTID label_column=MB_NAME type=area
>
>
> Running the following will give a raster in which a portion of the 
> cells do not have a label.
>
> v.extract input=boundary_county where="NAME='WAKE'" output=WakeCounty
>
> v.overlay ainput=boundary_municp binput=WakeCounty operator=and 
> output=WakeMunicp olayer=0,1,0
>
> g.region vector=WakeMunicp res=100 -a
>
> v.to.rast input=WakeMunicp output=A02 use=attr 
> attribute_column=OBJECTID label_column=MB_NAME type=area
>
>
> I also tried:
>
> v.extract input=boundary_municp where="COUNTY='WAKE'" output=WakeMunicp2
>
> g.region vector=WakeMunicp2 res=100 -a
>
> v.to.rast input=WakeMunicp2 output=A03 use=attr 
> attribute_column=OBJECTID label_column=MB_NAME type=area
>
>
> Same results, some of the raster cells do not get a label. I guess I 
> am overlooking something here, but I can't figure out what goes wrong 
> here. Any ideas?
>
Addition info, if I look at the cats file in 
~/nc_spm_08_grass7/user1/cats of A02 or A03 (created earlier, see 
above), there are a number or rows that look like e.g.,:

992:996:Morrisville

The same category values in the cats file of A01 are:

992:Morrisville
994:Lexington
996:Morrisville


> Regards
>
> Paulo



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