On Mon, 17 Jun 2019 09:46:20 +1200, Mike Taves wrote:
I'm not sure how SpatiaLite has implemented ST_Length,
but could be worth checking into.
Hi Mike,
SpatiaLite started supporting geodesic distances
about ten years ago, and two different methods
were implemented as internal C functions:
1.
On Sat, 15 Jun 2019 at 03:32, Nicolas Cadieux
wrote:
> I am trying to get the length of a line in python. (Not just the straight
> length between the first and last nodes). Using geopandas, (therefore the
> Shapely lib) I am getting the euclidien distance even though the dataframe
> holdings t
Awesome!
Den lør. 15. jun. 2019 kl. 23.04 skrev Even Rouault <
even.roua...@spatialys.com>:
> $ cat test.csv
> id,WKT
> 1,"LINESTRING(2 49,3 50,4 49)"
>
> $ ogr2ogr test.db test.csv -f sqlite -dsco spatialite=yes -a_srs EPSG:4326
>
> $ ogrinfo test.db -sql "select st_length(geometry, 1) from test
$ cat test.csv
id,WKT
1,"LINESTRING(2 49,3 50,4 49)"
$ ogr2ogr test.db test.csv -f sqlite -dsco spatialite=yes -a_srs EPSG:4326
$ ogrinfo test.db -sql "select st_length(geometry, 1) from test" -al -q
Layer name: SELECT
OGRFeature(SELECT):0
st_length(geometry, 1) (Real) = 265450.955822012
Cf
Thanks every one for your help,
I found good packages out there. I will probably go with Proj. I’am just
surprised it’s not part standard libraries like Shapely or OGR since both can
calculate line length. Most packages look like they are made to calculate only
two point at a time and not, fo
In the PROJ package, the geod utility is included - you could do
echo lat0 lon0 lat1 lon1 | geod -I +ellps=GRS80
Where the "-I" indicates that you want to calculate the "inverse geodetic
problem", i.e. you know where you are, and where you want to go, but you
need to know how far to go and in wh
How is the line defined? If you have a function, there's calculus.
On Sat, Jun 15, 2019, 12:43 AM Nicolas Cadieux
wrote:
> Thanks,
> Could work but I think this will be too slow. I wonder how QGIS does it? I
> guess they use code from Proj.4. If anyone has an other idea, shoot!
> Cheers
> Nicol
Thanks,
Could work but I think this will be too slow. I wonder how QGIS does it? I
guess they use code from Proj.4. If anyone has an other idea, shoot!
Cheers
Nicolas
> Le 14 juin 2019 à 13:20, Patrick Young a
> écrit :
>
> Not exactly what you want, but you can do this with PostGIS by cast
Thanks,
The link brings me to some helpful packages. I thought gdal could be helpful
as is has a very good OGR library that deals with this stuff.
Nicolas
> Le 14 juin 2019 à 12:19, Atle Frenvik Sveen a écrit :
>
> Hi!
>
> Not sure if would want to use gdal for this task*, but take a loo
Not exactly what you want, but you can do this with PostGIS by casting your
geometry to the geography type:
https://postgis.net/workshops/postgis-intro/geography.html
On Fri, Jun 14, 2019 at 10:26 AM Atle Frenvik Sveen
wrote:
> Hi!
>
> Not sure if would want to use gdal for this task*, but take
Hi!
Not sure if would want to use gdal for this task*, but take a look at this blog
post:
https://janakiev.com/blog/gps-points-distance-python/
*or if it's doable, i guess not, since the scope of gdal is reading/writing
geospatial formats
-a
-
Atle Frenvik Sveen
a...@frenviksveen.net
Hi,
I am trying to get the length of a line in python. (Not just the straight
length between the first and last nodes). Using geopandas, (therefore the
Shapely lib) I am getting the euclidien distance even though the dataframe
holdings the line geometries has a CRS (WGS84, zone UTM 18 S). Obv
12 matches
Mail list logo
