Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here
NAME
t.vect.observe.strds - Observes specific locations in a space time raster dataset over a period of time using vector points.KEYWORDS
temporal, sampling, vector, timeSYNOPSIS
t.vect.observe.strds
t.vect.observe.strds --helpt.vect.observe.strds input=name strds=name[,name,...] output=name vector_output=name columns=string[,string,...] [where=sql_query] [t_where=sql_query] [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
- --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 input vector map
- Or data source for direct OGR access
- strds=name[,name,...] [required]
- Name of the input space time raster datasets
- output=name [required]
- Name of the output space time vector dataset
- vector_output=name [required]
- Name of the new created vector map that stores the sampled values in different layers
- columns=string[,string,...] [required]
- Names of the vector columns to be created and to store sampled raster values, one name for each STRDS
- where=sql_query
- WHERE conditions of SQL statement without 'where' keyword
- Example: income < 1000 and inhab >= 10000
- t_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'
Table of contents
DESCRIPTION
The module t.vect.observe.strds is used to observe specific locations in a space time raster dataset over a period of time using vector points. The first input is a vector map layer with vector points. The second input is one or several space time raster datasets (STRDS) that should be sampled over time at the vector point positions. The space time raster dataset will be sampled over its whole temporal extent (from start to end). The range can be adjusted using the temporal where condition t_where. The temporal "where" will only work as expected when just one STRDS is to be sampled. If more than one STRDS are to be observed, a column name must be specified for each input space time raster dataset.As results a new space time vector dataset is generated that contains a single (new) vector map that links to as many time stamped attribute tables as raster map layer are present in the input space time raster dataset. Hence, for each time step in the space time raster dataset a new attribute table is created. The GRASS GIS Temporal Framework allows to time stamp attribute tables that can be linked to a single vector map layer.
The module v.what.rast is used internally for sampling the time stamped raster map layers. All sampled values of a single time stamped raster map layer are written into a new time stamped attribute table.
Use t.vect.db.select to print attribute values of the space time vector dataset to stdout.
EXAMPLE
The example show how to create a space time vector dataset and a vector layer starting from a point vector and a space time raster dataset:
t.vect.observe.strds input=precip_30ynormals_3d strds=tempmean_monthly \
output=precip_stations vect=precip_stations_monthly \
columns=month
t.info precip_stations type=stvds
+-------------------- Space Time Vector Dataset -----------------------------+
| |
+-------------------- Basic information -------------------------------------+
| Id: ........................ precip_stations@climate_2009_2012
| Name: ...................... precip_stations
| Mapset: .................... climate_2009_2012
| Creator: ................... lucadelu
| Temporal type: ............. absolute
| Creation time: ............. 2014-12-02 00:42:39.187615
| Modification time:.......... 2014-12-02 00:42:55.215169
| Semantic type:.............. mean
+-------------------- Absolute time -----------------------------------------+
| Start time:................. 2009-01-01 00:00:00
| End time:................... 2013-01-01 00:00:00
| Granularity:................ 1 month
| Temporal type of maps:...... interval
+-------------------- Spatial extent ----------------------------------------+
| North:...................... 306221.830194
| South:...................... 27606.895351
| East:.. .................... 917004.829165
| West:....................... 151768.568246
| Top:........................ 1615.44
| Bottom:..................... 2.4384
+-------------------- Metadata information ----------------------------------+
| Vector register table:...... vector_map_register_be074525097c4088997c9a1979f17065
| Number of points ........... 6664
| Number of lines ............ 0
| Number of boundaries ....... 0
| Number of centroids ........ 0
| Number of faces ............ 0
| Number of kernels .......... 0
| Number of primitives ....... 6664
| Number of nodes ............ 0
| Number of areas ............ 0
| Number of islands .......... 0
| Number of holes ............ 0
| Number of volumes .......... 0
| Number of registered maps:.. 49
|
| Title:
| Observaion of space time raster dataset(s) tempmean_monthly
| Description:
| Observation of space time raster dataset(s) tempmean_monthly with vector map precip_30ynormals_3d
| Command history:
| # 2014-12-02 00:42:39
| t.vect.observe.strds input="precip_30ynormals_3d"
| strds="tempmean_monthly" output="precip_stations"
| vect="precip_stations_monthly" columns="month"
|
+----------------------------------------------------------------------------+
v.info precip_stations_monthly
+----------------------------------------------------------------------------+
| Name: precip_stations_monthly |
| Mapset: climate_2009_2012 |
| Location: nc_spm_temporal_workshop |
| Database: /grassdata |
| Title: North Carolina 30 year precipitation normals (3D) |
| Map scale: 1:1 |
| Name of creator: neteler |
| Organization: |
| Source date: Wed May 9 14:32:39 2007 |
| Timestamp (first layer): none |
|----------------------------------------------------------------------------|
| Map format: native |
|----------------------------------------------------------------------------|
| Type of map: vector (level: 2) |
| |
| Number of points: 136 Number of centroids: 0 |
| Number of lines: 0 Number of boundaries: 0 |
| Number of areas: 0 Number of islands: 0 |
| Number of faces: 0 Number of kernels: 0 |
| Number of volumes: 0 Number of holes: 0 |
| |
| Map is 3D: Yes |
| Number of dblinks: 49 |
| |
| Projection: Lambert Conformal Conic |
| |
| N: 306221.830194 S: 27606.895351 |
| E: 917004.829165 W: 151768.568246 |
| B: 2.4384 T: 1615.44 |
| |
| Digitization threshold: 0 |
| Comment: |
| |
+----------------------------------------------------------------------------+
SEE ALSO
t.create, t.info, t.vect.db.select, t.vect.what.strdsAUTHOR
Sören Gebbert, Thünen Institute of Climate-Smart AgricultureLast changed: $Date: 2016-02-09 09:21:24 -0800 (Tue, 09 Feb 2016) $
SOURCE CODE
Available at: t.vect.observe.strds source code (history)
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.4, available here.
Updated manual page: here
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© 2003-2018 GRASS Development Team, GRASS GIS 7.0.7svn Reference Manual