[GRASS-user] Making fake dem's

[Roger Mason]

Hello Hamish,

Hamish <hamish_nospam at yahoo.com> writes:

> Roger Mason wrote:
>
>> > why not takeing real DEMs? The SRTM dataset is for free and can be
>> > used  with grass.
>> 
>> Because I want to make specific landscape shapes.  It would be an
>> immense labour to search the archive of DEM's to find what I want.
>
> Another idea is to use r.mapcalc to make a gaussian bell etc.

Thank you, I'll give that a try.

>> > take a look at r.surf.fractal which is creating synthetic DEMs
>> > for you.
>> 
>> I have GRASS installed on two machines.  r.surf.fractal worked fine on
>> my machine at home (6.2.1) but does not exist on my work machine (also
>> 6.2.1).  In both cases GRASS was installed from source.  Can you tell
>> me what libraries r.surf.fractal depends on so I can figure out how to
>> re-configure and re-build?
>
> GRASS needs to be built with FFTW support for r.surf.fractal to work.
> Note about that just added to the help page.

Yes, after poking around I guessed that might be the case and rebuilt
with fftw support but have not tested yet.  Thanks for confirming my suspicions.

Many thanks for your help.

Roger