v.what.rast3(1grass) | GRASS GIS User's Manual | v.what.rast3(1grass) |
v.what.rast3 - Uploads 3D raster values at positions of vector points to the table.
vector, sampling, raster, position, querying, attribute table, surface information
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]
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.
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
v.db.addtable, v.db.select, v.what.rast, v.what.vect, v.univar
Soeren Gebbert, heavily based on v.what.rast by Radim Blazek
Available at: v.what.rast3 source code (history)
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