NAME
r3.what - Queries 3D raster in specified 2D or 3D coordinates.
KEYWORDS
raster3d,
query,
voxel
SYNOPSIS
r3.what
r3.what --help
r3.what [-mz] input=name [coordinates=east,north[,east,north,...]] [coordinates_3d=east,north,top[,east,north,top,...]] [points=name] [output=name] [separator=character] [null_value=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -m
- Use 3D raster mask (if exists) with input map
- -z
- Ignore points Z values
- --overwrite
- Allow output files to overwrite existing files
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- input=name [required]
- Input 3D raster map
- coordinates=east,north[,east,north,...]
- Query with 2D coordinates
- coordinates_3d=east,north,top[,east,north,top,...]
- Query with 3D coordinates
- points=name
- Name of vector points map for query
- Or data source for direct OGR access
- output=name
- Name for output file
- separator=character
- Field separator
- Special characters: pipe, comma, space, tab, newline
- Default: pipe
- null_value=string
- String representing NULL value
- Default: *
r3.what queries 3D raster at specified coordinates. The
input
parameter is a valid 3D raster map in the current mapset search path.
The
output parameter is used to output results in a text file.
If
output is not specified or '-' is used, then standard output
(stdout) is used.
Coordinates can be specified directly using options coordinates
as coordinate pairs (east, north), or using option coordinates_3d
as east, north and top. If the coordinates are 2D, the result will be
a list of values representing the vertical column of the 3D raster at that
coordinates (from bottom to top). If 3D coordinates are provided only one value
is returned. User can specify multiple coordinates.
Another option is to specify
vector points map using option points. It can be either 2D or 3D.
If a 3D vector points map is specified, one 3D raster value per point is printed.
If that is not desired, flag z will ignore the z coordinate and
the module returns values for the vertical column.
We create a 3D raster where values depend on the depth.
We query the 3D raster with two 2D coordinates:
g.region s=0 n=100 w=0 e=100 b=0 t=100 res3=1 res=1 tbres=10 -p3
r3.mapcalc "new = depth()"
r3.what input=new@user1 coordinates=10,20,50,50
10.000000|20.000000|1.000000|2.000000|3.000000|4.000000|5.000000|6.000000|7.000000|8.000000|9.000000|10.000000
50.000000|50.000000|1.000000|2.000000|3.000000|4.000000|5.000000|6.000000|7.000000|8.000000|9.000000|10.000000
Here we query the 3D raster with two 3D coordinates:
r3.what input=new@user1 coordinates_3d=10,10,1,10,10,11
10.000000|10.000000|1.000000|1.000000
10.000000|10.000000|11.000000|2.000000
r.what,
r3.out.ascii,
v.what.rast3,
g.region
Anna Petrasova, NCSU GeoForAll Lab
SOURCE CODE
Available at:
r3.what source code
(history)
Latest change: Monday Jan 30 19:52:26 2023 in commit: cac8d9d848299297977d1315b7e90cc3f7698730
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GRASS Development Team,
GRASS GIS 8.4.1dev Reference Manual