On Sat, Oct 27, 2018 at 10:00 AM Frank David <[email protected]> wrote: > > > Le 26/10/2018 à 21:11, Markus Metz a écrit : > > > > On Fri, Oct 26, 2018 at 7:17 PM Frank David <[email protected]> wrote: > > > If you want to preserve attribute values, use v.patch -e, otherwise don't use the -e flag, but then you might get duplicate category values. > > > v.patch -c should not work because -c is not a recognised flag. Which GRASS version did you use with v.patch -c? > > I'm sorry, when I wrote -c it was -e of course ! I'm using Grass 7.4.1 > > But even with -e, as I wrote, the cat of the second file is shift by one... (?)
This is correct because it is needed to preserve attributes. > > I have used -e because I need to add my attribute table from both file. But I had imagine to keep cat relation with data, but it's may be better to add a id field ? is there any way to increment a unique key automatically when data are appended ? This unique key is automatically incremented when data are appended and attribute values need to be preserved. The unique key (more generally: the object identifier that determines to which category an object belongs) is the category value. I am sure the output with shifted category values is exactly the output you want when preserving attribute values. Markus M > > Frank > > > Markus M > > > > Frank > > > > Le 26/10/2018 à 18:44, Markus Metz a écrit : > > > > > > > > On Fri, Oct 26, 2018 at 2:26 PM Frank David <[email protected]> wrote: > > > > > > I reply to myself, > > > > > > I mistook, if I append, I see a cat shift too. The fisrt cat of the > > > second map is shift by one. It's strange no ? > > > > Suppose there is a feature with cat 1 in map A and a feature also with cat 1 in map B, but corresponding attribute values for cat 1 are different between map A and map B. In order to avoid such conflicts, v.patch shifts category values and updates the resultant attribute table accordingly, such that attributes for each feature are preserved. > > > > Markus M > > > > > > Frank > > > > > > Le 26/10/2018 à 14:17, Frank David a écrit : > > > > > > > Hi Stephan, > > > > > > > > If I add two vector in a new one with : > > > > > > > > v.patch -c input=map1,map2 out=map3 > > > > > > > > I notice the map3 first cat start at 2 instead of 1, so all cat are > > > > shifted by one. Do you have an idea of the reason ? > > > > > > > > If I append my map1 with map2 : > > > > > > > > v.patch -c -a input=map2 output=map1 --overwrite it works well > > > > > > > > Thank you > > > > > > > > Frank > > > > > > > > Le 26/10/2018 à 12:01, Stefan Blumentrath a écrit : > > > >> Hi, > > > >> > > > >> Try: > > > >> v.patch -a > > > >> https://grass.osgeo.org/grass76/manuals/v.patch.html > > > >> > > > >> (assuming attribute tables are equal). > > > >> > > > >> Cheers > > > >> Stefan > > > >> > > > >> -----Original Message----- > > > >> From: grass-user<[email protected]> On Behalf Of Frank David > > > >> Sent: fredag 26. oktober 2018 11:39 > > > >> To:[email protected] > > > >> Subject: [GRASS-user] append data after a v.in.ascii import > > > >> > > > >> Hello, > > > >> > > > >> I wonder what is the best way to append a vector map and his attribute data created with v.in.ascii ? > > > >> > > > >> Thanks > > > >> > > > >> Frank > > > >> > > > >> _______________________________________________ > > > >> grass-user mailing list > > > >> [email protected] > > > >> https://lists.osgeo.org/mailman/listinfo/grass-user > > > > > > > > _______________________________________________ > > > > grass-user mailing list > > > > [email protected] > > > > https://lists.osgeo.org/mailman/listinfo/grass-user > > > _______________________________________________ > > > grass-user mailing list > > > [email protected] > > > https://lists.osgeo.org/mailman/listinfo/grass-user
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