On Wed, 2008-11-12 at 05:35 +0100, Nikos Alexandris wrote: > Why isn't the cat column starting from 1 after (v.)patching vector maps > (whose cat's start normally from 1)? Is it that my maps have somethig > wrong? Is there a specific reason?
(Following up with a long example) I don't understand how v.patch and v.category work. Probably I misunderstand v.category. I kindly request for some assistance to clear-up my confusion. Regards, Nikos Help pages state: 1. v,patch -e Copy also attribute table Only the table of layer 1 is currently supported Question: Does this have anything to do with the cat starting from 2 in my example below? 2. v.category option=del "v.category attaches, deletes or reports vector categories to map geometry. These categories (IDs) are used to link geometry object(s) to attribute record (from attribute table linked to vector map)." del: delete category Question: Do the v.category options have any "obvious" effect, i.e. something that the end-user can see in the attribute table? # two imported shapefiles far away from each other (no overlaps) # 1rst vector map: daun_test # info of 1st map v.info -t daun_test nodes=143 points=0 lines=0 boundaries=142 centroids=62 areas=62 islands=1 faces=0 kernels=0 primitives=204 ## head of daun_test db.select daun_test | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 1|2592_5562|daun|2005|3 2|2594_5562|daun|2005|3 3|2584_5560|daun|2005|3 4|2586_5560|daun|2005|3 ## tail of daun_test db.select daun_test | tail -5 58|2578_5540|daun|2005|3 59|2580_5540|daun|2005|3 60|2582_5540|daun|2005|3 61|2584_5540|daun|2005|3 62|2586_5540|daun|2005|3 # 2nd vector map: trier_test # topology of 2nd map v.info -t trier_test nodes=240 points=0 lines=0 boundaries=239 centroids=110 areas=110 islands=1 faces=0 kernels=0 primitives=349 ## head of trier_test db.select trier_test | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 1|2558_5524|trier|2005|1 2|2552_5522|trier|2005|1 3|2556_5522|trier|2005|1 4|2558_5522|trier|2005|1 ## tail of trier_test db.select trier_test | tail -5 106|2538_5492|trier|2005|1 107|2540_5492|trier|2005|1 108|2542_5492|trier|2005|1 109|2538_5490|trier|2005|1 110|2540_5490|trier|2005|1 # patching test1 with "-e" flag v.patch -e input=daun_test,trier_test out=patching_test1 Patching vector map <[EMAIL PROTECTED]>... Patching vector map <[EMAIL PROTECTED]>... Building topology for vector map <patching_test1>... 553 primitives registered 954 vertices registered Building areas: 100% 172 areas built 2 isles built Attaching islands: 100% Attaching centroids: 100% Topology was built Number of nodes : 383 Number of primitives: 553 Number of points : 0 Number of lines : 0 Number of boundaries: 381 Number of centroids : 172 Number of areas : 172 Number of isles : 2 Intersections at borders will have to be snapped Lines common between files will have to be edited The header information also may have to be edited v.patch complete. 2 vector maps patched # cat of patched map starts with 2 db.select patching_test1 | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 2|2592_5562|daun|2005|3 3|2594_5562|daun|2005|3 4|2584_5560|daun|2005|3 5|2586_5560|daun|2005|3 ### Why not with 1?? # simple patching: works fine but, as expected, does not keep attribute tables v.patch input=daun_test,trier_test out=patching_test2 Patching vector map <[EMAIL PROTECTED]>... Patching vector map <[EMAIL PROTECTED]>... Building topology for vector map <patching_test2>... 553 primitives registered 954 vertices registered Building areas: 100% 172 areas built 2 isles built Attaching islands: 100% Attaching centroids: 100% Topology was built Number of nodes : 383 Number of primitives: 553 Number of points : 0 Number of lines : 0 Number of boundaries: 381 Number of centroids : 172 Number of areas : 172 Number of isles : 2 Intersections at borders will have to be snapped Lines common between files will have to be edited The header information also may have to be edited v.patch complete. 2 vector maps patched # head of test2 db.select patching_test2 | head -5 cat 1 2 3 4 an EXTRA question: # v.category option=report v.category patching_test1 option=report Layer/table: 1/patching_test1 type count min max point 0 0 0 line 0 0 0 boundary 0 0 0 centroid 172 2 174 area 0 0 0 all 172 2 174 # "v.category option=del" dos not remove categories in attribute table # Question: Is this right or wrong? db.select patching_test1_DELETED | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 2|2592_5562|daun|2005|3 3|2594_5562|daun|2005|3 4|2584_5560|daun|2005|3 5|2586_5560|daun|2005|3 # v.category option=report v.category input=patching_test1_DELETED option=report ## no output for patching_test1_DELETED. I suppose this is correct # or v.category patching_test1 out=patching_test1_DELETED2 option=del cat=2 # gives the same attribute table output!? db.select patching_test1_DELETED2 | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 2|2592_5562|daun|2005|3 3|2594_5562|daun|2005|3 4|2584_5560|daun|2005|3 5|2586_5560|daun|2005|3 # and report v.category input=patching_test1_DELETED2 option=report ## gives nothing, same as with patching_test1_DELETED above # or v.category patching_test1 out=patching_test1_DELETED3 option=del id=3 # again the same output!? db.select patching_test1_DELETED2 | head -5 cat|RAS2X2_NR|BLOCK|BEFL_JAHR|block_id 2|2592_5562|daun|2005|3 3|2594_5562|daun|2005|3 4|2584_5560|daun|2005|3 5|2586_5560|daun|2005|3 ## should this be the expected output here? # report on DELETED3 gives something which is identical with the "original" vector!? ## What is the option "id" doing exactly? v.category input=patching_test1_DELETED3 option=report Layer/table: 1/patching_test1_DELETED3 type count min max point 0 0 0 line 0 0 0 boundary 0 0 0 centroid 172 2 174 area 0 0 0 all 172 2 174 _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
