[GRASS-user] New modules in add-ons: v.in.geoplot, r.xtent + r.burn.frict

[Benjamin Ducke]

The two are made for very different but equally specific purposes:

r.carve actually "carves" rivers into a DEM, subtracting their depths
from the DEM.

r.burn.frict does essentially the same job as v.to.rast would, except
it performs some anti-aliasing on line edges, so there is no case like
this:

   0100
   0010
   0001

where a cost surface algorithm that scans for 8 directions could 
"slip" diagonally through the cells that represent a boundary line.
Instead, the line would be rasterized like this:

   0100
   0110
   0011

This is (only?) useful for rasterizing lines onto friction surfaces.
It's really just a primitive little script that I wrote because I needed
it for territorial modeling with r.xtent which involves cost surfaces.

Ben


Markus Neteler wrote:
> On Mon, Sep 28, 2009 at 4:26 PM, Benjamin Ducke
> <benjamin.ducke at oxfordarch.co.uk> wrote:
>> http://grass.osgeo.org/wiki/GRASS_AddOns#r.burn.frict
>>
>> r.burn.frict converts vector geometries to raster cells, using a simple anti-aliasing method to close "gaps" between diagonal cells. Useful for "burning" vector geometries into a friction surface, making sure that simulated movement does not "slip" through converted cells that have only diagonal neighbours.
> 
> Hi Benjamin,
> 
> out of curiosity: what's the difference to r.carve?
> 
> Markus
> 


-- 
Benjamin Ducke
Senior Applications Support and Development Officer

Oxford Archaeological Unit Limited
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Tel: +44 (0)1865 263 800 (switchboard)
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benjamin.ducke at oxfordarch.co.uk




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