NAME

       v.what.rast3  - Uploads 3D raster values at positions of vector points to the table.

KEYWORDS

       vector, sampling, raster, position, querying, attribute table, surface information

SYNOPSIS

       v.what.rast3
       v.what.rast3 --help
       v.what.rast3   map=name    [layer=string]    raster_3d=name   column=name   [where=sql_query]    [--help]
       [--verbose]  [--quiet]  [--ui]

   Flags:
       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       map=name [required]
           Name of vector points map for which to edit attributes
           Or data source for direct OGR access

       layer=string
           Layer number or name
           Vector features can have category values in different layers. This number determines which  layer  to
           use. When used with direct OGR access this is the layer name.
           Default: 1

       raster_3d=name [required]
           Name of existing 3D raster map to be queried

       column=name [required]
           Name of attribute column to be updated with the query result

       where=sql_query
           WHERE conditions of SQL statement without ’where’ keyword
           Example: income < 1000 and population >= 10000

DESCRIPTION

       v.what.rast3  reads  3D  raster  value  for  each  point  in  the vector and updates col column in vector
       attribute table by this value. The column should be type double. This module is based on v.what.rast.
       If more points have the same category, attribute value is set to NULL.  If  3D  raster  values  is  NULL,
       attribute value is set to NULL.

NOTES

EXAMPLES

       A)  Reading values from 3D raster map at position of vector points, writing these values into a column of
       the attribute table connected to the vector map:
       v.what.rast3 map=pnts raster3d=plume column=concentration

       B) In case of a vector map without attached attribute table, first add a new attribute table. This  table
       is then populated with values queried from the raster map:
       # create new random 3d vector points map
       v.random -z output=pnts npoints=100 zmin=0  zmax=50
       # add new table, link to map
       v.db.addtable map=pnts column="concentration double precision"
       # query raster map and upload values to vector table into specified column
       g.region raster3d=plume -p
       v.what.rast3 map=pnts raster3d=plume column=concentration
       # verify new attribute table:
       v.db.select map=pnts
       # verify statistics of uploaded values:
       v.univar map=pnts column=concentration type=point

SEE ALSO

        v.db.addtable, v.db.select, v.what.rast, v.what.vect, v.univar

AUTHOR

       Soeren Gebbert, heavily based on v.what.rast by Radim Blazek

SOURCE CODE

       Available at: v.what.rast3 source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual