[GRASS-dev] [GRASS GIS] #3263: r.to.vect: option to filter raster values

[GRASS GIS]

#3263: r.to.vect: option to filter raster values
-------------------------------+-------------------------
 Reporter:  martinl            |      Owner:  grass-dev@…
     Type:  enhancement        |     Status:  new
 Priority:  normal             |  Milestone:  7.4.0
Component:  Raster             |    Version:  svn-trunk
 Keywords:  r.to.vect, values  |        CPU:  Unspecified
 Platform:  Unspecified        |
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 It would be useful to introduce for G72:r.to.vect `values` option
 similarly to G72:d.rast for filtering raster values. Let's say that we
 have viewshed map with two categories (1 - visible, 0 - invisible):

 {{{
 r.category viewA
 0
 1
 }}}

 We would like convert to vector map only visible areas. Currently we need
 to run G72:r.mapcalc or G72:r.reclass to be able to perform this task:

 {{{
 r.mapcalc  expr='viewA1 = if(viewA == 0, null(), 1)'
 r.to.vect -sv input=viewA1 out=viewA type=area  -t
 }}}

 With `values` option we could perform this task by running just one
 command:

 {{{
 r.to.vect -sv input=viewA out=viewA type=area -t values=1
 }}}

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Ticket URL: <https://trac.osgeo.org/grass/ticket/3263>
GRASS GIS <https://grass.osgeo.org>