[GRASSLIST:6312] Re: filling nulls in integer raster

Hamish hamish_nospam at yahoo.com
Sat Apr 2 00:07:02 EST 2005

> i have a raster image that i am hoping to vectorize after a bit of 
> generalization with r.reclass.area... however, r.reclass.area leaves
> nulls in  the middle of larger areas of equal value:
> i have tried to fill these holes, with r.fillnulls (via RST
> interpolation)  with: 
> r.fillnulls in=asp.large out=asp.final smooth=.01 tension=100
> and the result looks something like this:
> ...however, is there anyway to get rid of all the nulls, replacing
> them with  the value that is surrounding them?

sneaking suspicion: there are no NULLs.

try running r.univar on the map to count number of NULLs.

It may be that the color map does not cover the whole range of data, and
the out of bounds areas are left looking blank. Try running r.colors on
the new map. If the map should be categorical, and as r.fillnulls
returns a floating point map, you might also try feeding through

r.mapcalc 'new_map=int(old_map)'

maybe with int(old_map+0.5) if you want rounding. (int() just chops off
everything to the right of the decimal place)


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