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On 15/03/2019 22:45, Martin Landa
wrote:
Hi, pá 15. 3. 2019 v 15:01 odesílatel Moritz Lennert <[email protected]> napsal:v.to.db with options start/end provides the coordinates of these points.thanks, I overlooked `v.to.db`. Anyway I would still need to hack around since `v.to.db` does not create a new output vector map. So it's still make sense to me to implement this functionality in `v.to.points`.Ma Whenever we get new Lidar data, I run a script to extract the streamlines network, then obtain the upstream flow accumulation area for both ends of each stream reach. The script uses a combination of v.db.update to get the x,y coordinates of both ends of each stream reach. Then these coordinates are extracted and piped into v.in.ascii, creating a new points vector. Next I get the upstream contributing area from the flow accumulation raster (v.what.rast). Finally an sql _expression_ is constructed for db.execute to update the streams vector with upstream area for each reach from the end points vector.
So, for me, an option in v.to.points to get the start and end points would help to simplify this workflow.
Cheers, Micha -- Micha Silver Ben Gurion Univ. Sde Boker, Remote Sensing Lab cell: +972-523-665918 |
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