I need to convert a vector contour map to a raster so I can apply the
hydrologic models modules.
Reading the v.to.rast manual page I learned that I needed to add categories
to the input contour map. Running v.category added no categories: "0
features added."
v.info does not tell me anything
On Wed, 10 May 2023, Rich Shepard wrote:
Which v.db* should I use to find the elevation colum associated with each
contour line?
Long ago I used the GUI and it had a menu to examine the vector map's table.
Now, I just leared that v.db.select will work. There're more columns than I
need, but
On Wed, 10 May 2023, Rich Shepard wrote:
Is there an r.* module to interpolate elevations between the contour lines
so I have cells?
There are several r.resamp.* modules in the core distribution. Please advise
me which would be most appropriate for my rasterized contour elevation map.
TIA,
Sounds like the vector geometry was already 3D, that's the case when you
use use=z. If the vector would be 2D (see v.info) you would have to use the
attribute table.
On Wed, May 10, 2023 at 12:14 PM Rich Shepard
wrote:
> My current topographic vector data file has a column name for the
On Wed, 10 May 2023, Anna Petrášová wrote:
Sounds like the vector geometry was already 3D, that's the case when you
use use=z. If the vector would be 2D (see v.info) you would have to use the
attribute table.
Anna,
When I used the 2D file, regardless of which parameter I used or both,
My current topographic vector data file has a column name for the elevation
data, ContourEle. Reading the v.to.rast page there is a use parameter (with
'z' for elevation) and an attribute_column parmater. Because the vector
map's database table does not have a column named 'z', but the one named
On Wed, 10 May 2023, Rich Shepard wrote:
There are several r.resamp.* modules in the core distribution. Please advise
me which would be most appropriate for my rasterized contour elevation map.
Should I use one of the v.surf.* modules then re-rasterize the resulting
map? If so, please
I think you need to interpolate and not simply convert vector lines to
raster lines. Make sure lines have an attribute with elevation (or z
coordinate) and use e.g. v.surf.rst module.
Māris.
trešd., 2023. g. 10. maijs, plkst. 17:29 — lietotājs Rich Shepard
() rakstīja:
>
> I need to convert a
On Wed, 10 May 2023, Maris Nartiss wrote:
I think you need to interpolate and not simply convert vector lines to
raster lines. Make sure lines have an attribute with elevation (or z
coordinate) and use e.g. v.surf.rst module.
Māris.
Interpolating the vector contour file before rasterizing
On Wed, May 10, 2023 at 9:14 PM Rich Shepard
wrote:
> I don't understand why a raster elevation map with DCELL precision is
> rejected by r.slope.aspect. The region was set to the vector analysis area.
>
> r.info tells me this about the elevation map:
>
>
I don't understand why a raster elevation map with DCELL precision is
rejected by r.slope.aspect. The region was set to the vector analysis area.
r.info tells me this about the elevation map:
++
| Map: dem2014
On Wed, May 10, 2023 at 12:34 PM Rich Shepard
wrote:
> On Wed, 10 May 2023, Anna Petrášová wrote:
>
> > Sounds like the vector geometry was already 3D, that's the case when you
> > use use=z. If the vector would be 2D (see v.info) you would have to use
> the
> > attribute table.
>
> Anna,
>
>
Hi,
In addition, here is an overview page:
https://grasswiki.osgeo.org/wiki/Interpolation
Markus
On Wed, May 10, 2023 at 8:16 PM Maris Nartiss wrote:
>
> I think you need to interpolate and not simply convert vector lines to
> raster lines. Make sure lines have an attribute with elevation (or
On Wed, 10 May 2023, Rich Shepard wrote:
Thanks very much. I'm learning many new things on this project and still
need to meet regulator's deadlines.
Markus,
The wiki page on 'Contour lines to DEM' is what I need.
Best regards,
Rich
___
On Wed, 10 May 2023, Markus Neteler wrote:
In addition, here is an overview page:
https://grasswiki.osgeo.org/wiki/Interpolation
Markus,
Thanks very much. I'm learning many new things on this project and still
need to meet regulator's deadlines.
Much appreciated,
Rich
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