If you are sure lines are horizontal, then you can copy coordinates of the from-node (or the to-node, anyway) of each line to your table.
Vincent. Le samedi 29 novembre 2008 à 11:18 -0600, Nick Cahill a écrit : > Dear Hamish, > > Yes, the lines are absolutely horizontal - every point has the same > elevation. I tried v.to.db before writing to the list. But v.to.db > only has options to upload the following values: cat, area, compact, > perimeter, length, count, coor, start, end, sides, query, slope. A > v.what query on a typical line has: > > Map: con10 > Mapset: PERMANENT > Type: Line > Line: 2110 > Length: 432.740896 > Line height: 200.000000 > Layer: 1 > Category: 2110 > > Driver: mysql > Database: sardisutm > Table: con10 > Key column: cat > cat : 2110 > type : 4 > level : 3 > graphicgroup : 0 > colorindex : 3 > weight : 0 > style : 0 > entitynum : > mslink : > text : > > I tried just typing "line height" into v.to.db anyway, but got a > predictable error > > ERROR: value <line height> out of range for parameter <option> > Legal range: > cat,area,compact,perimeter,length,count,coor,start,end,sides,query,slope > > I just figured out that you can get the information from v.out.ascii, > and then discard the coordinates and such; but it seems like there > should be an easier way of accessing this information. > > Many thanks! > > Nick Cahill > > > > On Nov 28, 2008, at 7:14 PM, Hamish wrote: > > > Nick wrote: > >> I have a series of contour vector maps imported from a CAD > >> program (Microstation). The CAD maps were in 3d, and the 3d > >> information was successfully imported into GRASS, so the > >> vectors have line heights as well as length, etc. Now I need > >> to export these into shapefiles. When I do this, all the > >> other useless CAD data like line color, style, weight, etc. > >> is exported as attributes in the .dbf file, but line height > >> is not -- it is not a field in the mySQL database but is > >> part of the geometry of the line, if I understand what's > >> going on here correctly. Is there a way to transfer line > >> height into the attribute table so I can access and export > >> it? Many thanks, > > > > v.db.addcol + v.to.db ? > > > > note that unless lines are perfectly horizontal (eg elevation > > contours) > > you can not assign a single elevation value to a line's attributes (as > > each vertex will have its own value, and the attribute is associated > > with > > the line as a whole), so I would expect in general for it to refuse > > to try. > > > > as for 3D shapefile export, ummm... check the wiki, help pages, and ML > > archives. It rings a bell but I've no idea how. > > > > > > Hamish > > > > > > > > > > > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
