[GRASS-user] How to create DEM from shp file?

[Moritz Lennert]

On 24/01/08 14:45, Ardiansyah wrote:
> I need suggestions.
> 
> I used v.to.rast to convert vector in shp file. I assigned one colomn 
> (elevation) in database as value of  pixels.
> It works well. Then to make it surface, I use r.surf.contour and it took 
> very long time (more than 5 hours) until I finally
> canceled it.
> 
> Question : How long the r.surf.contour is running normally ?

This depends on your region settings. You should make sure that the 
extents of your region do not go beyond the extents of your dem. I've 
also found that if you want to speed up the process you can create a 
mask which covers just the area you need to interpolate.

Also, from the man page: "The speed of r.surf.contour is dependent on 
how far "apart" the contour lines are from each other (as measured in 
raster cells). Since a flood fill algorithm is used, the program's 
running time will grow exponentially with the distance between contour 
lines.".

> How to make certain resolution in that command. I want my DEM map will 
> have 30mx30m resolution as landsat image.

g.region -a res=30.

Moritz