table of contents
| t.vect.extract(1grass) | GRASS GIS User's Manual | t.vect.extract(1grass) |
NAME¶
t.vect.extract - Extracts a subset of a space time vector dataset.
KEYWORDS¶
temporal, extract, vector, time
SYNOPSIS¶
t.vect.extract
t.vect.extract --help
t.vect.extract [-n] input=name
[where=sql_query] [expression=sql_query]
output=name [layer=string]
[type=string[,string,...]]
[basename=string] [suffix=string]
[nprocs=integer] [--overwrite] [--help]
[--verbose] [--quiet] [--ui]
Flags:¶
Parameters:¶
- input=name [required]
-
Name of the input space time vector 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=sql_query
-
WHERE conditions of SQL statement without ’where’ keyword
Example: income < 1000 and population >= 10000 - output=name [required]
-
Name of the output space time vector dataset - 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 - type=string[,string,...]
-
Input feature type
Options: point, line, boundary, centroid, area
Default: point,line,boundary,centroid,area - 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
-
The number of v.extract processes to run in parallel. Use only if database backend is used which supports concurrent writing
Default: 1
DESCRIPTION¶
The purpose of t.vect.extract is to extract a subset of a space time vector dataset and to store that subset in a different space time vector dataset.
EXAMPLE¶
In the following example a new space time vector dataset will be
create with all the data later than 2000:
t.vect.extract input=shoreline where="start_time > 2000" \
output=shoreline_later_2000 basename=new_shoreline t.info shoreline_later_2000@shoreline type=stvds
+-------------------- Space Time Vector Dataset -----------------------------+
| |
+-------------------- Basic information -------------------------------------+
| Id: ........................ shoreline_later_2000@shoreline
| Name: ...................... shoreline_later_2000
| Mapset: .................... shoreline
| Creator: ................... lucadelu
| Temporal type: ............. relative
| Creation time: ............. 2014-11-29 08:43:50.043219
| Modification time:.......... 2014-11-29 08:43:50.085407
| Semantic type:.............. mean
+-------------------- Relative time -----------------------------------------+
| Start time:................. 2003
| End time:................... 2009
| Relative time unit:......... years
| Granularity:................ 1
| Temporal type of maps:...... point
+-------------------- Spatial extent ----------------------------------------+
| North:...................... 1039175.31479
| South:...................... 34705.216018
| East:.. .................... 3052322.44671
| West:....................... 2130004.16779
| Top:........................ 0.0
| Bottom:..................... 0.0
+-------------------- Metadata information ----------------------------------+
| Vector register table:...... vector_map_register_8395740fc8de42149fef74a3d25bbb05
| Number of points ........... 0
| Number of lines ............ 407
| Number of boundaries ....... 0
| Number of centroids ........ 0
| Number of faces ............ 0
| Number of kernels .......... 0
| Number of primitives ....... 407
| Number of nodes ............ 767
| Number of areas ............ 0
| Number of islands .......... 0
| Number of holes ............ 0
| Number of volumes .......... 0
| Number of registered maps:.. 3
|
| Title:
| North Carolina shoreline
| Description:
| North Caroline shoreline from 2000 to 2009
| Command history:
| # 2014-11-29 08:43:50
| t.vect.extract input="shoreline"
| where="start_time > 2000" output="shoreline_later_2000"
| basename="new_shoreline"
| # 2014-11-29 08:44:14
| t.support type="stvds"
| input="shoreline_later_2000@shoreline"
| descr="North Caroline shoreline from 2000 to 2009"
+----------------------------------------------------------------------------+ t.vect.list shoreline_later_2000 name|layer|mapset|start_time|end_time shoreline_2003|None|shoreline|2003|None shoreline_2004|None|shoreline|2004|None shoreline_2009|None|shoreline|2009|None
SEE ALSO¶
t.create, t.info
AUTHOR¶
Sören Gebbert, Thünen Institute of Climate-Smart Agriculture
SOURCE CODE¶
Available at: t.vect.extract source code (history)
Accessed: Sunday Jan 22 07:37:46 2023
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© 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
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