[GRASS-user] serious problem with "ROUND-OFF"

[achim]

Thanks, but r.to.vect is not a problem, since I increase the resolution
by 3 and using a script, that produce a correct conversion.

(see picture)
Re: [GRASS-user] Re: IN: raster-flow-direction OUT:vector-network?


Hamish schrieb:
> try temporarily increasing the region resolution by 2x for
> the r.to.vect step.
> 
> ?
> Hamish 
> 
> 
> 
> --- On Tue, 29/9/09, achim <ak7 at jupiter.uni-freiburg.de> wrote:
> 
>> From: achim <ak7 at jupiter.uni-freiburg.de>
>> Subject: [GRASS-user] serious problem with "ROUND-OFF"
>> To: "grass-user" <grass-user at lists.osgeo.org>
>> Received: Tuesday, 29 September, 2009, 11:01 PM
>> Hi all,
>>
>> I have a problem, I really would like to solve, because
>> many problems
>> occur in my theses in further steps.
>>
>> What I do is:
>>
>> 1. I break lines at some lengths.
>> 2. I use both vector- and raster-data for analysis, which
>> is eg.
>> updating points with raster-values or converting lines and
>> points to raster.
>>
>> The Problems are (due to rounding or "non-snapping"?):
>> !Points from lines on the edge between two diagonal cells
>> (see pictures)!
>> These points do:
>> 1. not belong precisely to one cell (compared with the line
>> they come
>> from (see picture v.to.rast.png)
>> 2. These points sometimes don't lie on on the cells, the
>> line is
>> referred to (see picture break.png)
>>
>> Any hints are very welcomed!
>>
>> Thanks in advance,
>> Achim
>>
>> -----Inline Attachment Follows-----
>>
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> 
> 
>       
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