t.rast.extract
Extracts a subset of a space time raster datasets.
t.rast.extract [-n] input=name [where=sql_query] [expression=string] output=name [basename=string] [suffix=string] [nprocs=integer] [--overwrite] [--verbose] [--quiet] [--qq] [--ui]
Example:
t.rast.extract input=name output=name
grass.script.run_command("t.rast.extract", input, where=None, expression=None, output, basename=None, suffix="gran", nprocs=1, flags=None, overwrite=False, verbose=False, quiet=False, superquiet=False)
Example:
gs.run_command("t.rast.extract", input="name", output="name")
Parameters
input=name [required]
Name of the input space time raster dataset
where=sql_query
WHERE conditions of SQL statement without 'where' keyword used in the temporal GIS framework
Example: start_time > '2001-01-01 12:30:00'
expression=string
r.mapcalc expression assigned to all extracted raster maps
output=name [required]
Name of the output space time raster dataset
basename=string
Basename of the new generated output maps
A numerical suffix separated by an underscore will be attached to create a unique identifier
suffix=string
Suffix to add at basename: set 'gran' for granularity, 'time' for the full time format, 'num' for numerical suffix with a specific number of digits (default %05)
Default: gran
nprocs=integer
Number of r.mapcalc processes to run in parallel
Default: 1
-n
Register Null maps
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
input : str, required
Name of the input space time raster dataset
Used as: input, strds, name
where : str, optional
WHERE conditions of SQL statement without 'where' keyword used in the temporal GIS framework
Example: start_time > '2001-01-01 12:30:00'
Used as: sql_query
expression : str, optional
r.mapcalc expression assigned to all extracted raster maps
output : str, required
Name of the output space time raster dataset
Used as: output, strds, name
basename : str, optional
Basename of the new generated output maps
A numerical suffix separated by an underscore will be attached to create a unique identifier
suffix : str, optional
Suffix to add at basename: set 'gran' for granularity, 'time' for the full time format, 'num' for numerical suffix with a specific number of digits (default %05)
Default: gran
nprocs : int, optional
Number of r.mapcalc processes to run in parallel
Default: 1
flags : str, optional
Allowed values: n
n
Register Null maps
overwrite: bool, optional
Allow output files to overwrite existing files
Default: False
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
The purpose of t.rast.extract is to extract a subset of a space time raster dataset and to store that subset in a different space time raster dataset. The where condition is used to select the subset. In addition a r.mapcalc sub-expression can be specified that performs operations on all maps of the selected subset. In this expression the name of the input space time raster dataset can be used as simple map name. Other STRDS than the input STRDS can not be specified, but any raster map. In case a r.mapcalc sub-expression is defined, the base name of the resulting raster maps must be specified. The r.mapcalc expression can be used to select maps as well, since by default resulting empty maps are not registered in the output space time raster dataset and removed after processing. The number of parallel GRASS GIS processes can be specified to speed up the processing.
If no r.mapcalc expression is defined, the selected maps are simply registered in the new created output space time raster dataset to avoid data duplication.
NOTES
The r.mapcalc sub-expression should not contain the left side
"map ="
of a full r.mapcalc expression, only the right side, eg.:
t.rast.extract input=tempmean_monthly where="start_time > '2010-01-05'" output=selected_tempmean_monthly basename=new_tmean_month expression="if(tempmean_monthly < 0, null(), tempmean_monthly)"
EXAMPLE
t.rast.extract input=tempmean_monthly output=tempmean_monthly_later_2012 where="start_time >= '2012-01-01'"
t.rast.list tempmean_monthly_later_2012
name|mapset|start_time|end_time
2012_01_tempmean|climate_2000_2012|2012-01-01 00:00:00|2012-02-01 00:00:00
2012_02_tempmean|climate_2000_2012|2012-02-01 00:00:00|2012-03-01 00:00:00
2012_03_tempmean|climate_2000_2012|2012-03-01 00:00:00|2012-04-01 00:00:00
2012_04_tempmean|climate_2000_2012|2012-04-01 00:00:00|2012-05-01 00:00:00
2012_05_tempmean|climate_2000_2012|2012-05-01 00:00:00|2012-06-01 00:00:00
2012_06_tempmean|climate_2000_2012|2012-06-01 00:00:00|2012-07-01 00:00:00
2012_07_tempmean|climate_2000_2012|2012-07-01 00:00:00|2012-08-01 00:00:00
2012_08_tempmean|climate_2000_2012|2012-08-01 00:00:00|2012-09-01 00:00:00
2012_09_tempmean|climate_2000_2012|2012-09-01 00:00:00|2012-10-01 00:00:00
2012_10_tempmean|climate_2000_2012|2012-10-01 00:00:00|2012-11-01 00:00:00
2012_11_tempmean|climate_2000_2012|2012-11-01 00:00:00|2012-12-01 00:00:00
2012_12_tempmean|climate_2000_2012|2012-12-01 00:00:00|2013-01-01 00:00:00
SEE ALSO
AUTHOR
Sören Gebbert, Thünen Institute of Climate-Smart Agriculture
SOURCE CODE
Available at: t.rast.extract source code
(history)
Latest change: Wednesday Apr 02 17:48:37 2025 in commit 571253a