[Gvsig_english] Fwd: raster buffer

[André Pais]

Thank you so much Dietrich. I followed your procedure and the result looks
great (I just had to multiply the result by my mask). The max distance is
exactly the same that I got using Arcmap.

Regards, André.

2012/10/3 Simon Cropper <simoncropper at fossworkflowguides.com>

> On 03/10/12 00:26, Andre Pais wrote:
> >
> >
> > ---------- Forwarded message ----------
> > From: *Andre Pais* <[hidden email]
> > </user/SendEmail.jtp?type=node&node=5005887&i=0>>
> > Date: 2012/9/29
> > Subject: [Gvsig_english] raster buffer
> > To: [hidden email] </user/SendEmail.jtp?type=node&node=5005887&i=1>
> >
> >
> > Hi there,
> >
> > So I need to generate a raster theme that represents the distance to the
> > road network of a certain area. I started with the shapefile that
> represents
> > the road network, then I converted it to raster using "rasterize vector
> > layer". Now, I need to use a function that makes buffers to the road
> network
> > similar to "Euclidean Distance" of Arcmap. I´ve tried "raster buffer" of
> > Sextante but it doesn´t return what I need. For example, in the
> function´s
> > options I defined my input (the road network raster) and the buffer
> distance
> > as 100 (my cell size). The output varies from 0 to 2 and I cannot
> understand
> > what it represents nor its appearance looks minimally similar with what
> I´ve
> > done with Arcmap.
> >
> > I would bery much appreciate an answer
> >
> > Regards, André Pais.
> >
> >
> >
> [snip]
>
> André,
>
> Is this what you are trying to do?
>
> Using Sextante...
>
> 1. Buffer road (1 concentric ring at 500m)
> 2. Convert buffer from Polygon to Polylines
> 3. Merge Line Layers and simplify
> 4. Assign Double Number representing distance (0 for road, 500 for buffer)
> 5. Convert Merged Line Layer to Raster, i.e. {Rasterize vector layer}
> 6. {Void Filling}
>
> Gives you a raster, similar to a DEM generated from contours but instead
> of elevation you are using distance from road as the variable.
>
> --
> Cheers Simon
>
>     Simon Cropper - Open Content Creator
>
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