[GRASS-dev] [GRASS GIS] #3335: v.to.rast with label_column set results in raster with part of raster cells without label

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1

#3335: v.to.rast with label_column set results in raster with part of raster cells
without label
-------------------------+-------------------------
Reporter: pvanbosgeo | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 7.2.1
Component: Default | Version: unspecified
Keywords: | CPU: Unspecified
Platform: Unspecified |
-------------------------+-------------------------
Converting a vector to raster does in some specific cases yields yields
issues with the labeling. E.g., the following (using the 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
}}}

or:

{{{
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.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3335&gt;
GRASS GIS <https://grass.osgeo.org>

2

#3335: v.to.rast with label_column set results in raster with part of raster cells
without label
--------------------------+-------------------------
  Reporter: pvanbosgeo | Owner: grass-dev@…
      Type: defect | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: unspecified
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by mmetz):

Replying to [ticket:3335 pvanbosgeo]:

The problem appears when a label is assigned to a range of values, e.g.
{{{
992:996:Morrisville
}}}

this means that all raster values from 992 to 996 should get the same
label "Morrisville". The raster library supports writing such a range of
values for all map types with Rast_set_cat(), but reading such a range of
values is supported only for fp maps (FCELL, DCELL).

Please try trunk r70900.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3335#comment:1&gt;
GRASS GIS <https://grass.osgeo.org>

3

#3335: v.to.rast with label_column set results in raster with part of raster cells
without label
--------------------------+-------------------------
  Reporter: pvanbosgeo | Owner: grass-dev@…
      Type: defect | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: unspecified
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by pvanbosgeo):

Replying to [comment:1 mmetz]:
> Replying to [ticket:3335 pvanbosgeo]:
>
> The problem appears when a label is assigned to a range of values, e.g.
> {{{
> 992:996:Morrisville
> }}}
>
> this means that all raster values from 992 to 996 should get the same
label "Morrisville". The raster library supports writing such a range of
values for all map types with Rast_set_cat(), but reading such a range of
values is supported only for fp maps (FCELL, DCELL).
>
> Please try trunk r70900.

Quick try, seems to work now, thanks. So this means it now works for
integer maps as well?

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3335#comment:2&gt;
GRASS GIS <https://grass.osgeo.org>

4

#3335: v.to.rast with label_column set results in raster with part of raster cells
without label
--------------------------+-------------------------
  Reporter: pvanbosgeo | Owner: grass-dev@…
      Type: defect | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: unspecified
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by mmetz):

Replying to [comment:2 pvanbosgeo]:
> Replying to [comment:1 mmetz]:
> > Replying to [ticket:3335 pvanbosgeo]:
> >
> > The problem appears when a label is assigned to a range of values,
e.g.
> > {{{
> > 992:996:Morrisville
> > }}}
> >
> > this means that all raster values from 992 to 996 should get the same
label "Morrisville". The raster library supports writing such a range of
values for all map types with Rast_set_cat(), but reading such a range of
values is supported only for fp maps (FCELL, DCELL).
> >
> > Please try trunk r70900.
>
> Quick try, seems to work now, thanks. So this means it now works for
integer maps as well?

Yes, getting a label for a range of values now works for CELL maps as well
(setting a label for a range of values was already possible).

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3335#comment:3&gt;
GRASS GIS <https://grass.osgeo.org>