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] [expres-
sion=sql_query] output=name [layer=string]
[type=string[,string,...]] [basename=string] [suffix=string]
[nprocs=integer] [--overwrite] [--help] [--verbose] [--quiet]
[--ui]
Flags:
-n
Register empty maps
--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]
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 ac-
cess 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 vec-
tor 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: unknown
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GRASS 7.8.7 t.vect.extract(1grass)
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