[GRASS-user] Generate DEM with point and line vector

[Hamish]

leonidas wrote:
> I need to generate a DEM using a line vector file (contours,
> step=20m, some are disjoined) and also combine a second point
> vector file with heights.How can I achieve that with Grass?

v.to.rast + r.surf.contour

> In the contours file there is also the coastline (height=0).Will
> that produce any error?

yes, please read the r.surf.contour help page carefully about
that.


the quick workaround is to use r.mapcalc to multiply your raster
input with:

r.mapcalc "contline_mult = (contlines*100000)+1"

then run r.surf.contour

then reverse the above multiplication:

r.mapcalc "dem = (contour_dem -1) / 100000"



besides that pain r.surf.contour does a really nice job.


Hamish