[GRASS-dev] Re: [GRASS-user] v.clean tool=prune - 'thresh' interpreted wrong?

[Maciej Sieczka]

Hamish wrote:
> Maciej Sieczka wrote:

>> 	$ echo "L 4 1
>> 	 10 10
>> 	 20 10
>> 	 30 10
>> 	 40 10
>> 	 1     1" | v.in.ascii -n out=line format=standard
>>
>>
>> So there are 4 vertices and the distance between each 2 following is
>> 10. Then I don't understand why the:
>>
>> 	$ v.clean input=line output=line_pruned type=line tool=prune
>> 	thresh=1

>> I declared thresh=1, the distance between vertices is 10 - so none
>> should be removed, but all are! And the same happens with all the lower
>> thresholds until thresh=0.03.

> what if there is some angle between the points? e.g.
> 
> v.in.ascii -n out=line format=standard << EOF
> L 4 1
>  10 10
>  20 5
>  30 7.5
>  40 10
>  1  1
> EOF

$ v.clean input=line output=line2_pruned type=line tool=prune thresh=1

$ v.out.ascii line2_pruned format=standard | awk 'NR>10'
L  3 1
 10           10
 20           5
 40           10
 1     1

The thresh=1, but v.clean prunes the 3rd vertex "30 7.5", which as far
from the other 2 vertices as ~10.3! I don't get it.

Any hints Radim?

Maciek