Hello list,
I have a vector with 115284 lines. From db.select I see
| cat | ID | Date |
| 1 | 278 | 1990-07-10 |
| 2 | 278 | 1992-07-30 |
| 3 | 278 | 1994-08-29 |
| 4 | 242 | 1998-06-05 |
| 5 | 255 | 2005-03-03 |
| 6 | 255 | 1985-09-05 |
| 7 | 255 | 1986-09-08 |
| 8 | 278 | 1997-09-08 |
That is, 115284 cats and 291 IDs.
I'd like to work with this as an STVDS. I know how to go about this if it were all rasters, but am still (after years) wrapping my head around the GRASS vector format and power.
Can someone advise how I would go about importing this into an STVDS?
My first thought was to extract each line to a new vector. Obviously inefficient.
Perhaps each ID to a new vector, and then each line (each unique Date) for each of those vectors is moved to a new layer?
Thanks,
-k.
P.S. Unrelated but somewhat related. Does STR3DS let me work with 4D data: 3D (xyz) rasters that then have a time component added? Or am I still limited to 3D data?
Hi List,
On 2023-12-01 at 16:30 -08, Ken Mankoff <mankoff@gmail.com> wrote...
I have a vector with 115284 lines. From db.select I see
| cat | ID | Date |
| 1 | 278 | 1990-07-10 |
| 2 | 278 | 1992-07-30 |
| 3 | 278 | 1994-08-29 |
| 4 | 242 | 1998-06-05 |
| 5 | 255 | 2005-03-03 |
That is, 115284 cats and 291 IDs.
Using just one ID to start with (with 80 timestamps) I've created 80 vectors, each with their own layer and v.timestamp. I can then patch these together to one product with multiple layers.
If I t.register all of these, I also see what I expect to see with g.gui.timeline. If I run "g.gui.animation stvds=t" it reports "Topology [...] is invalid".
Is there a way to export STVDs and see the time component in QGIS or KMZ/Google Earth?
Thanks,
-k.
Hello Ken,
Sorry for such a late reply. AFAIU and some old experience with STVDS, the approach is by date, i.e., you need a map per date. This is because of the snapshot logic of STDS. I remember having done animations with vector time series, but again, that was a long time ago. Have you tried calling the list of vector maps instead of the stvds? At least to understand if it is a temporal or spatial topology issue.
There was also a QGIS plugin by Soeren to visually explore STDS (https://www.youtube.com/watch?v=xxHt3jJbnYw), and IIUC the time manager of QGIS required only a vector file with a date field to show animations.
Best,
Vero
···
Dra. Verónica Andreo
Investigadora Adjunta de CONICET
Instituto Gulich (CONAE - UNC)
Centro Espacial Teófilo Tabanera (CETT)
Falda del Cañete - Córdoba, Argentina
+54 3547 400000 int. 1153
https://veroandreo.gitlab.io/