[GRASS-user] r.fillnulls for large area

GRASS GRASS user
1

Nick wrote:

Thanks for the advice to fill the ocean with
zeros. It worked better, and didn't get "killed",
but it still didn't work...This time it made it
further than before, but it got "abondoned" - see
the output below...

try editing the r.fillnulls script, on line 165
replace "r.to.vect input=..." with
"r.to.vect -b input=...". I think it would work,
but I'm not sure if it would make it slower to run
v.surf.rst or not. (?)

Maybe I need to split my region into subregions
and run r.fillnulls on each subregion then patch
them together.

yes, that should work well.

Number of nodes: 13428068

building topology for anything more that 3-5 million
cells will consume a large amount of memory due to
the cumulative effect of the small, but real,
memory requirement of each individual feature.
maybe if you had 16gb RAM 13 million would be ok?

Hamish

2

Nick wrote:

Maybe I need to split my region into subregions
and run r.fillnulls on each subregion then patch
them together.

Hamish:

yes, that should work well.

I always wanted to create a script to do that. Since (I think) r.fill.nulls identifies the null locations and creates small buffers around them, I believe that if we combined something like the region handling of, say, the r.roughness script, with r.fill.nulls, that would really speed up matters.

Don’t you think?

Cheers,
Marcello.