Hi!
I've installed grass 6.3, since in the descritption of v.distance
says "In lat-long locations v.distance gives distances (dist and
to_along) in meters not in degrees calculated as geodesic distances
on a sphere.".
I tried it out, but the values produced in a ll location are degrees!
I've checked the source code
(https://svn.osgeo.org/grass/grass/branches/releasebranch_6_3/vector/v.distance/)
and indeed it does not contain any source to compute meters, like
for example in the source for version 6.4.
So, am I correct, that the description is faulty for the 6.3
version, or am I missing something fundamental??
In the first case, could someone correct the desciption, since
it can cause somewhat loss of time and effort (like for me), if one
believes the current description...
Ed.
I've installed grass 6.3, since in the descritption of v.distance
says "In lat-long locations v.distance gives distances (dist and
to_along) in meters not in degrees calculated as geodesic distances
on a sphere.".
I can confirm 'dist' units are indeed given in decimal degrees in a
Lat/Long location in 6.4.
Devs, what is the intended behavior of the module? If this behavior
is a bug, would it be a simple fix? Otherwise, I'll modify the
docs to mention reported units in degrees.
~ Eric.
Hi,
2008/8/14 Patton, Eric <epatton@nrcan.gc.ca>:
I've installed grass 6.3, since in the descritption of v.distance
says "In lat-long locations v.distance gives distances (dist and
to_along) in meters not in degrees calculated as geodesic distances
on a sphere.".
I can confirm 'dist' units are indeed given in decimal degrees in a
Lat/Long location in 6.4.
do you mean 6.3?
Devs, what is the intended behavior of the module? If this behavior
is a bug, would it be a simple fix? Otherwise, I'll modify the
docs to mention reported units in degrees.
From r29568 [1] is distance (in LL locations) given in meters. Manual
pages in 6.3 should be fixed.
Martin
--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *
Hi,
2008/8/14 Martin Landa <landa.martin@gmail.com>:
[...]
From r29568 [1] is distance (in LL locations) given in meters. Manual
pages in 6.3 should be fixed.
sorry, I forgot the link
http://trac.osgeo.org/grass/changeset/29568
Martin
--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *
I can confirm 'dist' units are indeed given in decimal degrees in a
Lat/Long location in 6.4.
do you mean 6.3?
No, I meant 6.4, but checking 6.3.1.svn, 'dist' units are decimal
degrees as well.
From r29568 [1] is distance (in LL locations) given in meters. Manual
pages in 6.3 should be fixed.
Sorry, I'm a little confused; from the changeset, it appears that v.distance
was being corrected to able to report in meters, as lat and lon are not
equally scaled. So it seems that a bug in v.distance still exists, then?
Shouldn't r29568 have fixed this?
~ Eric.
Hi,
2008/8/14 Patton, Eric <epatton@nrcan.gc.ca>:
I can confirm 'dist' units are indeed given in decimal degrees in a
Lat/Long location in 6.4.
do you mean 6.3?
No, I meant 6.4, but checking 6.3.1.svn, 'dist' units are decimal
degrees as well.
no, in 6.4 you get distance in meters not decimal degrees. Just
computation is too slow.
>From r29568 [1] is distance (in LL locations) given in meters. Manual
pages in 6.3 should be fixed.
Sorry, I'm a little confused; from the changeset, it appears that v.distance
was being corrected to able to report in meters, as lat and lon are not
equally scaled. So it seems that a bug in v.distance still exists, then?
Shouldn't r29568 have fixed this?
Sorry, in which sense? In LL projection is used
Vect_line_geodesic_length() to calculate distances.
Martin
--
Martin Landa <landa.martin gmail.com> * http://gama.fsv.cvut.cz/~landa *