[GRASSLIST:203] Re: raster vs. vector

[Glynn Clements]

Antonios Christofides wrote:

> I've read here at there that GRASS is particularly good at raster, and
> people wondering whether they should use raster or vector. I'm a GRASS
> and GIS newbie, and I'm confused: I thought that whether you use raster
> or vector depends on the type of the data, not your preferences. I
> thought that the DEM would be raster, and that roads and streams would
> be vector. Do you mean I can represent roads in raster? How the heck?
> They'll be collections of points, not lines, and I won't be able to
> specify the width I want with ps.map.

Whilst it is more usual to represent roads, rivers etc as vectors, it
is possible to convert them to rasters. The choice of format
determines what type of processing you can do; e.g. you can use
r.buffer, r.cost etc on a raster representation.

Using vectors provides greater accuracy, but there are more processing
options for rasters.

-- 
Glynn Clements <glynn.clements at virgin.net>