Huidae, Moritz and all,
Many thanks for you suggestions for filling inter-contour area with
constant value.
I will try them out and report back.
Best
Venka
On 5/1/2014 4:03 AM, Huidae Cho wrote:
Ah.. if you have two adjacent contour lines that are farther than the
contour interval from each other, my method doesn't work. For example, 100,
102, and 106 will become 101, 103, and 107, not 101, 104, and 107 (what
should the max value be?).
Huidae
On Wed, Apr 30, 2014 at 2:50 PM, Huidae Cho <[email protected]> wrote:
Venka,
Let's say you have the elevation field in your shapefile and the contour
interval is 2 meters.
# Import your shapefile into GRASS
v.in.ogr dsn=contours.shp output=contours type=boundary
# Add centroids to the imported boundaries to make areas
v.centroids input=contours output=contourareas
# Convert the contour areas to raster filling inter-contour areas with
contour elevations
v.to.rast input=contourareas output=contourareas use=attr
attrcolumn=elevation
# Now you want to add a half of the contour interval to get what you want
r.mapcalc expression="contoursteps=contourareas+1"
contoursteps is what you need, I think.
Regards,
Huidae
On Tue, Apr 29, 2014 at 4:19 AM, Moritz Lennert <
[email protected]> wrote:
[Please keep threads on the list]
On 29/04/14 00:33, John Ciolek wrote:
Hi Moritz.
What do you mean by the following suggestion?
On Apr 28, 2014, at 2:45 AM, Moritz Lennert wrote:
- if necessary, add a line at the edge of the region and patch that
with your contour lines to close polygons (v.in.region, v.patch)
Are you suggesting that you can close a contour (connect the beginning
point to the ending point) using v.in.region or v.patch?
No, not the beginning point to the end point. Either you have closed
contours or your contours go over the edge of your current region, meaning
that some contours are not closed. So, in order to close them, you can do
so arbitrarily at the edge of your region by patching in a line that
represents that edge. This line can be created with v.in.region.
Moritz
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