[GRASS-user] derive points outlet from r.stream.extract

[Markus Neteler]

Hi Giuseppe,

Could you post a reproducible example with North Carolina samle data?
(being tight on time it would help)

Best
Markus

On Thu, Apr 23, 2020 at 8:53 PM Giuseppe Amatulli
<giuseppe.amatulli at gmail.com> wrote:
>
> Hi,
> I'm trying to extract the outlet location from the
> r.stream.extract stream_vector=stream  attribute.
> In particular the manual for r.stream.extract reports:
>
> "In layer 2, categories are identical to type_code in layer 1 with additional category 2 = outlet for outlet points."
>
> I want to be able to extract only the points of layer 2 where category = 2.
> However when I run
>
> v.db.connect  -p   map=stream
> Vector map <stream> is connected by:
> layer <1/stream> table <stream> in database </tmp/grass7-ga254-12721/tmploc/PERMANENT/sqlite/sqlite.db> through driver <sqlite> with key <cat>
>
> I can see only layer 1 (which does not contain category 2).
>
> Is there a way to connect to layer 2?
> How I can be sure that also layer 2 has been created and is not missing?
> Thanks
> Giuseppe
>
> GRASS 7.6.0 (tmploc):/gpfs/scratch60/fas/sbsc/ga254/dataproces/MERIT_HYDRO > v.info   map=stream
>  +----------------------------------------------------------------------------+
>  | Name:            stream                                                    |
>  | Mapset:          PERMANENT                                                 |
>  | Location:        tmploc                                                    |
>  | Database:        /tmp/grass7-ga254-25033                                   |
>  | Title:                                                                     |
>  | Map scale:       1:1                                                       |
>  | Name of creator: ga254                                                     |
>  | Organization:                                                              |
>  | Source date:     Thu Apr 23 14:42:51 2020                                  |
>  | Timestamp (first layer): none                                              |
>  |----------------------------------------------------------------------------|
>  | Map format:      native                                                    |
>  |----------------------------------------------------------------------------|
>  |   Type of map: vector (level: 2)                                           |
>  |                                                                            |
>  |   Number of points:       250905          Number of centroids:  0          |
>  |   Number of lines:        245570          Number of boundaries: 0          |
>  |   Number of areas:        0               Number of islands:    0          |
>  |                                                                            |
>  |   Map is 3D:              No                                               |
>  |   Number of dblinks:      1                                                |
>  |                                                                            |
>  |   Projection: Latitude-Longitude                                           |
>  |                                                                            |
>  |               N:       77:06:40.5N    S:       73:10:55.5N                 |
>  |               E:      158:07:46.5E    W:      135:26:34.5E                 |
>  |                                                                            |
>  |   Digitization threshold: 0                                                |
>  |   Comment:                                                                 |
>  |                                                                            |
>  +----------------------------------------------------------------------------+
>
>
>
> --
> Giuseppe Amatulli, Ph.D.
>
> Research scientist at
> School of Forestry & Environmental Studies
> Center for Research Computing
> Yale University
> New Haven, CT, USA
> 06511
> Teaching: http://spatial-ecology.net
> Work:  https://environment.yale.edu/profile/giuseppe-amatulli/
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-- 
Markus Neteler, PhD
https://www.mundialis.de - free data with free software
https://grass.osgeo.org
https://courses.neteler.org/blog