[GRASS-user] another v.net - question

[achim]

Even though the coordinates are identical, I had to snap the lines via
v.clean with a very small thresh.

By the way, the common node of the two of the three was generated by
breaking on the node of the other. Maybe some rounding issues?

(This is something I tried before, but unfortunately with type=point).

Once again, I wonder and once again a light dawned on me.

Thanks for participation,
Achim

achim schrieb:
> Hi,
> 
> I am still dealing with this serious problem (for me at least).
> 
> v.net produces sometimes two nodes, where one should be, while on some
> points, where (tree) lines touching one is produced.
> 
> The coordinates are exactly the same. Naturally, removing double
> geometry features results in missing points (cats).
> 
> I tried with grass 6.4 and 6.5.
> 
> I tried to reproduce it in spearfish, without success.
> 
> 
> What could it be?
> I'm really stuck here.
> Help is very welcome!
> Achim
> 
> Stranded, I am attaching a small example on
> 
> EPSG 4326 (res 0:00:30 x 0:00:30)
> 
> projection: 3 (Latitude-Longitude)
> zone:       0
> datum:      wgs84
> ellipsoid:  wgs84
> north:      9:00:15N
> south:      7:40:45N
> west:       27:30:45E
> east:       28:34:01.066017E
> nsres:      0:00:30
> ewres:      0:00:29.890284
> rows:       159
> cols:       127
> cells:      20193
> 
> Here is one correct and one non-correct node built, using v.net:
> v.net --overwrite input=lines_example output=lines_example_net
> 
> after renewing cats, I get the following output of:
> v.net --overwrite input=lines_example_import_net
> output=lines_example_import_net operation=nreport
> 1 1
> 2 2,1,5
> 3 2
> 4 3
> 5 3
> 6 6,4
> 7 4
> 8 5
> 9 6
> 
> 
> achim schrieb:
>> Hi,
>>
>> running v.net with does not build nodes where it should:
>>
>> When having three lines touching in one point, sometimes two nodes
>> instead of one common are generated.
>>
>> has it to do with the direction of lines, that should be connected to a
>> node?
>>
>> Can I force somehow to build one node connecting all connected lines?
>>
>> Best regards,
>> Achim
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