I've (succesfuly) imported an arc info vector
file in geographic (lat,lon) coordinates using v.in.arc
Then I have transformed the ascii vector file from the
original geographic coordinates to Goode-Homolosine
coordinates using a non-Grass program.
Once I import the new ascii vector using v.in.ascii,
there is one single error: one node is very far away
from the region. This is probably due to some wrong
character written by the program doing the transformation.
I would need to identify the EXACT coordinates of this
node, then I would be able to search for it in the
ascii vector file, correct it and run v.in.ascii
again.
Nevertheless, I've tried both v.what and v.digspline
(i'm using grass5.0beta), and I've identified that this
wrong node is node 23 on line 23, but cannot get the
coordinates: I get cursor coordinates, but
not the coordinates of the node.
Is there any way I could identify the EXACT coordinates
of any given node?
Thanks
Agus
Dr. Agustin Lobo
Instituto de Ciencias de la Tierra (CSIC)
Lluis Sole Sabaris s/n
08028 Barcelona SPAIN
tel 34 93409 5410
fax 34 93411 0012
alobo@ija.csic.es
http://pangea.ija.csic.es/alobo
Agustin Lobo wrote:
Nevertheless, I've tried both v.what and v.digspline
(i'm using grass5.0beta), and I've identified that this
wrong node is node 23 on line 23, but cannot get the
coordinates: I get cursor coordinates, but
not the coordinates of the node.
If it is v.support that give you the error message, the error is in
the attribute file (line 23 of $LOCATION/dig_att/<vector file name>),
not in the line itself and means that one label cannot be attached
to a line.
If another program gives you the error message, it would be helpfull
to give the program name and the error message...
--
Michel Wurtz ENGEES - CEREG
1, quai Koch - BP 1039, F-67070 STRASBOURG cedex
Tel: +33 03.88.24.82.45 Fax: +33 03.88.37.04.97
On Thu, 8 Jul 1999, Michel Wurtz - ENGEES/CEREG wrote:
If it is v.support that give you the error message, the error is in
the attribute file (line 23 of $LOCATION/dig_att/<vector file name>),
not in the line itself and means that one label cannot be attached
to a line.
If another program gives you the error message, it would be helpfull
to give the program name and the error message...
Sorry for the missunderstanding: it is not an error message, the programs
run without issuing any error at all. But the result is wrong.
As I indicated in my original message, the problem is most
likely due to an error in the (non-grass) program that projects
lat,lon coordinates into Goode-Homolosine. I can visualize
the wrong node, but cannot find it in the
ascii vector file to correct it. The problem could be solved if
I could know the exact coordinates of the node, as I could
just search the coordinates with the editor. So, my question,
again, is
how can I get the exact coordinates of a given node?
As far as I've seen, both d.what.vect and v.digspline give
cursor coordiantes, not node coordinates.
Thanks for your help
Agus
Agustin Lobo wrote:
how can I get the exact coordinates of a given node?
OK, sorry for the first answer : I will try
d.vect (visualise the wrong node)
d.zoom (getting closer)
d.what.vect to look at the node (=> display x and y xoordinates)
vi (or any other editor) to look at something close (most significant
digits of coordinates) in the ascii vector file.
Of course, you can loop the two first until you have enough precision.
(and don't forget to do d.erase after each zoom)
--
Michel Wurtz ENGEES - CEREG
1, quai Koch - BP 1039, F-67070 STRASBOURG cedex
Tel: +33 03.88.24.82.45 Fax: +33 03.88.37.04.97