[GRASS-dev] v.what.strds: timestamp column

GRASS GRASS developer
1

Hi,

I am playing with `v.what.strds` in order to get space-time-related
nearest raster value information from strds based on given timestamp
stored in attribute table.

Input: vector map with timestamp column, eg:

cat|time
6|2020-01-08 03:00:00

Goal: get a single raster value from strds based on timestamp.

cat|time|value
6|2020-01-08 03:00:00|253

Instead of that v.what.strds returns a new column for each raster map
registered in strds.

cat|time|map_1,map_2,map_3
6|2020-01-08 03:00:00||253|

Is there any other tool which could do the job or should I modify
v.what.strds in order to solve this task? Eg.

v.what.strds time_column=time ...

Thanks for in advance, Martin

--
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa

2

Hi Martin,

Afaik, v.what.strds is just a wrapper for v.what.rast for all the maps in the raster time series. It does not consider the column time in the vector. Then there’s t.vect.what.strds that uses a space-time vector data set (STVDS) to query a STRDS, but in my opinion to create a STVDS is a bit of a hassle (one vector map per date).

The only module that I’m aware of that takes a vector with dates to query a STRDS is Luca’s add-on t.rast.what.aggr (https://grass.osgeo.org/grass78/manuals/addons/t.rast.what.aggr.html), but it’s aim is to get aggregates before or after the dates provided in the vector.

HTH,
Vero

El lun., 15 jun. 2020 17:20, Martin Landa <landa.martin@gmail.com> escribió:

Hi,

I am playing with v.what.strds in order to get space-time-related
nearest raster value information from strds based on given timestamp
stored in attribute table.

Input: vector map with timestamp column, eg:

cat|time
6|2020-01-08 03:00:00

Goal: get a single raster value from strds based on timestamp.

cat|time|value
6|2020-01-08 03:00:00|253

Instead of that v.what.strds returns a new column for each raster map
registered in strds.

cat|time|map_1,map_2,map_3
6|2020-01-08 03:00:00||253|

Is there any other tool which could do the job or should I modify
v.what.strds in order to solve this task? Eg.

v.what.strds time_column=time …

Thanks for in advance, Martin

–
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa

grass-dev mailing list
grass-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-dev

3

Hei Martin,

What about:

https://grass.osgeo.org/grass78/manuals/addons/v.what.strds.timestamp.html

Written for the IRSAE course at Studenterhytta (Oslo, Norway), in order to e.g. spatio-temporal match temperature timeseries and GPS-tracking data.

Cheers,

Stefan

···

Hi Martin,

Afaik, v.what.strds is just a wrapper for v.what.rast for all the maps in the raster time series. It does not consider the column time in the vector. Then there’s t.vect.what.strds that uses a space-time vector data set (STVDS) to query a STRDS, but in my opinion to create a STVDS is a bit of a hassle (one vector map per date).

The only module that I’m aware of that takes a vector with dates to query a STRDS is Luca’s add-on t.rast.what.aggr (https://grass.osgeo.org/grass78/manuals/addons/t.rast.what.aggr.html), but it’s aim is to get aggregates before or after the dates provided in the vector.

HTH,

Vero

El lun., 15 jun. 2020 17:20, Martin Landa <landa.martin@gmail.com> escribió:

Hi,

I am playing with v.what.strds in order to get space-time-related
nearest raster value information from strds based on given timestamp
stored in attribute table.

Input: vector map with timestamp column, eg:

cat|time
6|2020-01-08 03:00:00

Goal: get a single raster value from strds based on timestamp.

cat|time|value
6|2020-01-08 03:00:00|253

Instead of that v.what.strds returns a new column for each raster map
registered in strds.

cat|time|map_1,map_2,map_3
6|2020-01-08 03:00:00||253|

Is there any other tool which could do the job or should I modify
v.what.strds in order to solve this task? Eg.

v.what.strds time_column=time …

Thanks for in advance, Martin

–
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa

grass-dev mailing list
grass-dev@lists.osgeo.org
https://lists.osgeo.org/mailman/listinfo/grass-dev

4

On Tue, 16 Jun 2020 at 00:08, Stefan Blumentrath
<Stefan.Blumentrath@nina.no> wrote:

Hei Martin,

Hi,

What about:

https://grass.osgeo.org/grass78/manuals/addons/v.what.strds.timestamp.html

Written for the IRSAE course at Studenterhytta (Oslo, Norway), in order to e.g. spatio-temporal match temperature timeseries and GPS-tracking data.

I used it successfully few months ago

Cheers,

Stefan

--
ciao
Luca

www.lucadelu.org

5

Hi Stefan,

út 16. 6. 2020 v 0:03 odesílatel Stefan Blumentrath
<Stefan.Blumentrath@nina.no> napsal:

What about:

https://grass.osgeo.org/grass78/manuals/addons/v.what.strds.timestamp.html

Written for the IRSAE course at Studenterhytta (Oslo, Norway), in order to e.g. spatio-temporal match temperature timeseries and GPS-tracking data.

I have to buy some additional RAM for my brain :slight_smile: Thanks for
reminding me! Martin

--
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa