[GRASS-user] r.thin ?

[Achim Kisseler]

Hi,

how do you use r.thin? Can you post the complete command?


Am 09.11.2010 06:25, schrieb charlie:
> Hi. I am currently using Grass 6.4 on linux and beginning the the
> process of vectorizing an old NOAA raster map with r.thin. The map is
> approximately 12,000 pixels by 8,000 pixels wide.
>
> According to this post, (
> http://osgeo-org.1803224.n2.nabble.com/r-thin-td2718260.html#a2718260
> )the iteration variable has to be equal or larger than half the number
> of cells of the wider line so I increased the iterations to 6,000, and
> it would up finishing in approximately 4,200 passes.
>
> Previously, I was getting excellent preliminary results, with fewer
> (1,000) iterations, distinct features were visible, however at least 50%
> of the map was not completed.
>
> Now with an increase to 6,000 iterations r.thin completes, but the
> results are a single 1px wide horizontal line. Im sure I am overlooking
> something relatively simple; can anyone give me any advice on how to
> best run r.thin in this particular case?
>
> Thanks!
>
> Charlie
>
>
> <a href="www.wetlandresearch.com">Wetlands</a>
>
>
>
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