Michael, Just confirmed your issue.
v.random tmp100 npoints=100 seed=100 v.db.addtable tmp100 col="id varchar(20)" v.db.update tmp100 col=id qcol="'tmp100_' || cat" v.random tmp10 npoints=10 seed=10 v.db.addtable tmp10 col="id varchar(20)" v.db.update tmp10 col=id qcol="'tmp10_' || cat" v.patch tmp100,tmp10 out=tmp110 -e v.category tmp110 op=report Layer/table: 1/tmp110 type count min max point 110 2 112 line 0 0 0 boundary 0 0 0 centroid 0 0 0 area 0 0 0 face 0 0 0 kernel 0 0 0 all 110 2 112 In my case, all features in tmp10 are linked in tmp110. You can recategorize it. v.category tmp110 out=tmp110_nocats op=del cat=-1 v.category tmp110_nocats out=tmp110_recats op=add npnts100=$(v.info tmp100 -t | sed '/points=/!d; s/points=//') npnts10=$(v.info tmp10 -t | sed '/points=/!d; s/points=//') v.db.update tmp110_recats col=cat qcol=cat-1 where="cat<=$npnts100+1" v.db.update tmp110_recats col=cat qcol=cat-2 where="cat>$npnts100+1" Yeah... I know what you may think... Please create an issue on GitHub. Regards, Huidae On Thu, Mar 14, 2024 at 4:42 PM Michael Barton via grass-dev < grass-dev@lists.osgeo.org> wrote: > Thanks Doug and Vincent. > > None of this works. I vaguely remember having this same kind of road block > several years back. > > Nothing in v.category lets you change an existing cat value to a different > value > v.in.ogr MUST add a column that MUST be named cat (all else causes an > error--this is a bug) that is a series of consecutive integers from 1-n. So > I cannot create a file with a cat field that matches my vector areas. > > v.edit won't let you change an existing cat number AFAICT. No error but > nothing changes. > > Once I've imported a table using v.in.ogr, I cannot use db.drop.column to > delete the cat column--even if it is not being used as a key field. This > raises an error. > > No way to rename a column from cat to something else (or something else to > cat) unless you've already connected it to a vector map even if cat is not > the key field. So I can't create an integer column to link up my lost > vector area with a record in my csv file. > > This simple task is just not possible in GRASS AFAICT. Or if it is > possible, it can only be done by such non-obvious and convoluted means that > I've yet to find a method that works in spite of asking a large number of > very skilled GRASS users. > > Michael > _____________________________ > > C. Michael Barton > Associate Director, School of Complex Adaptive Systems ( > https://scas.asu.edu) > Professor, School of Human Evolution & Social Change ( > https://shesc.asu.edu) > Director, Center for Social Dynamics & Complexity ( > https://complexity.asu.edu) > Arizona State University > Tempe, AZ 85287-2701 > USA > > Executive Director, Open Modeling Foundation ( > https://openmodelingfoundation.github.io) > Director, Network for Computational Modeling in Social & Ecological > Sciences (https://comses.net) > > personal website: http://www.public.asu.edu/~cmbarton > > > On Mar 14, 2024, at 7:10 AM, Newcomb, Doug <doug_newc...@fws.gov> wrote: > > Have you tried a .csvt file for your .csv file? > https://gdal.org/drivers/vector/csv.html > <https://urldefense.com/v3/__https://gdal.org/drivers/vector/csv.html__;!!IKRxdwAv5BmarQ!dv7XjZX6-VnNpFbpXP6R1XYWkuaA4Y-gDR4RvL3bWazWUkLfURuKDMWqiBFqBS6jlNSHDKZCo02GJKjauaAJ-pCVIKD5JDc$> > > ------------------------------ > *From:* grass-dev <grass-dev-boun...@lists.osgeo.org> on behalf of > Michael Barton via grass-dev <grass-dev@lists.osgeo.org> > *Sent:* Wednesday, March 13, 2024 7:02 PM > *To:* GRASS developers <grass-dev@lists.osgeo.org>; GRASS user list < > grass-u...@lists.osgeo.org> > *Subject:* [EXTERNAL] [GRASS-dev] vector patching frustration > > > > * This email has been received from outside of DOI - Use caution before > clicking on links, opening attachments, or responding. * > > > I am completely stymied in my attempt to do what should be a simple task. > I have a map of vector areas, linked with an attribute table. I would like > to patch in one more vector area, for which I have equivalent attribute > information. I have tried this multiple ways and I cannot make this patch > happen so that the added area has attribute info. > > The closest I've come is to create and link a one line table to the new > area that has exactly the same fields as the larger vector area map. The > first map has 154 areas (i.e., cat=1-155). When I patch the maps and look > at the resulting attribute table, I indeed see line and cat 155. But it is > not linked with the patched area--which has been assigned a cat=183 for > reasons I cannot fathom. The patch also renumbers my cat field to cat=2-155 > from the original 1-154. > > This has been made more complicated by the fact that v.in.ogr imports all > columns of a *.csv as text, regardless of what is in them and assigns cat > numbers starting at 1. So I can't specify an integer key field of 155 to > try the linking. Nor can I change the assigned cat of the single area I am > trying to patch from 1 to 155 using v.category (or anything else I can > find). > > I'm hoping that someone has a clever solution that I've not seen or I'll > just have to do this fairly simple and straightforward vector operation in > QGIS. > > Michael > _____________________________ > C. Michael Barton > Associate Director, School of Complex Adaptive Systems ( > https://scas.asu.edu) > Professor, School of Human Evolution & Social Change ( > https://shesc.asu.edu) > Director, Center for Social Dynamics & Complexity ( > https://complexity.asu.edu) > Arizona State University > Tempe, AZ 85287-2701 > USA > > Executive Director, Open Modeling Foundation ( > https://openmodelingfoundation.github.io > <https://urldefense.com/v3/__https://openmodelingfoundation.github.io/__;!!IKRxdwAv5BmarQ!dv7XjZX6-VnNpFbpXP6R1XYWkuaA4Y-gDR4RvL3bWazWUkLfURuKDMWqiBFqBS6jlNSHDKZCo02GJKjauaAJ-pCVvuAToIA$> > ) > Director, Network for Computational Modeling in Social & Ecological > Sciences (https://comses.net > <https://urldefense.com/v3/__https://comses.net/__;!!IKRxdwAv5BmarQ!dv7XjZX6-VnNpFbpXP6R1XYWkuaA4Y-gDR4RvL3bWazWUkLfURuKDMWqiBFqBS6jlNSHDKZCo02GJKjauaAJ-pCVdW6V-z8$> > ) > > personal website: http://www.public.asu.edu/~cmbarton > > > _______________________________________________ > grass-dev mailing list > grass-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-dev > -- Huidae Cho, Ph.D., GISP, /hidɛ <http://ipa-reader.xyz/?text=hid%C9%9B> t͡ɕo/, 조희대, 曺喜大 GRASS GIS Developer https://idea.isnew.info/
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