[GRASS5] Problems with vector import, and a suggestion
mw at teledetection.fr
Wed, 13 Feb 2002 11:25:44 +0000
Aleksey Naumov wrote:
> Another question on the help page. It says:
> The attribute of each "vector" object (points, line, and polygon) is the
> Arc/Info coverage-ID (and not the coverage-#)."
> Use the "feature-ID" of the arc info objects to link geometry and
> attribute's tables. The default is to use the "feature-#" field (which is an
> internal link, but you should not rely on it for linking Arc/Info objects to
> an external database. (GRASS 5.0 option)"
> Sounds inconsistent, maybe just not clearly stated. Can it be made more clear
> in the help page?
Well... the first sentence is false (I must correct it in CVS)
> However you still need to supply "d.area" with "catnum"s in
> order to color areas by category. If you have 80 soil polygons and
> you want to color them according to the value in the "muid" attribute you'd
> have (after 'ln -s statsgo.muid statsgo') to list all the catnums explicitly,
> > d.area -f statsgo catnum=2,5,7,8,11,12,23
> after looking them up in 'dig_cat/statsgo', right?
hmm... another solution is to use the dig_cat file as an input for v.reclass
(this works only for integer cats !) : you have to suppress the header of the
dig_cat file and use a colon as separator... something like
sed -e '1,3d' -e 's/ */:/' $LOCATION/dig_cats/xxx.attribute | v.reclass xxx
> In the future I think
> 'dig_cat' should be retired in favor of a real database
YES ! I think the 5.1 vector file will help !
Michel WURTZ - DIG - Maison de la télédétection
500, rue J.F. Breton
34093 MONTPELLIER Cedex 5