[GRASS-stats] Raster maps from GRASS to R and back to GRASS?

[Dylan Beaudette]

On Monday 13 April 2009, Nikos Alexandris wrote:
> Nikos:
> > >> What I actually do is nothing but a PCA on a combination of different
> > >> bands. The fact is that bands a, b, c are of equal "length" in R and
> > >> have _more_ non-NULLs than bands d, e, f.
>
> [...]
>
> Dylan:
> > > One thing you might consider is generating a single NULL mask that
> > > represents NULL values that occur in any, or all bands -- akin to an OR
> > > operation. I think that na.omit(sp_object at data) may be able to return
> > > just the 'complete' data, along with a list of indices where NA values
> > > have been removed.
>
> Roger:
> > Would simply using complete.cases(x at data) be what you are looking for?
>
> So, this is the _correct and easy_ way instead of using a couple of |
> (=OR) operators in my case? Or am I misinterpreting it?
>
> Kindest regards, Nikos

Hi.

As usualy Roger's suggestion seems to be the simplest, most direct approach. 
It seems like a more general solution, as opposed to a sequence of 
is.na() | ... one for each raster map.

Dylan

-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341