[R] Re: [STATSGRASS] Using GRASS/R interface with an xy location & reverse(G) error

[Roger Bivand]

On Tue, 8 Feb 2005, Steven T.Stoddard wrote:

> Ok.  The work-around I can grow accustomed to, or I might fall back on 
> GRASS5.4 if that works.
> 
> I wonder if another problem that cropped up is somehow related to the 
> first.  Using interp=TRUE I managed to import a raster map to R.  But 
> when trying to plot it, I get the following:
> 
>  > plot(G,tt$rb1)
> Error in reverse(G) : cannot allocate vector of length 1086556160

What does summary(G) say? It sounds as though the numbers of rows and/or 
columns have the wrong values.

Over 1G cells is a bit extreme?

Roger

> 
> ???
> 
> Thanks for the help,
> Steve
> 
> 
> ---
> Steven T. Stoddard
> 
> Program in Ecology, Evolution and Conservation Biology
> University of Illinois at Urbana-Champaign
> 
> (217) 333-2235
> 302 Shelford Vivarium
> 606 E. Healy Ave
> Champaign, IL  61820
> http://www.life.uiuc.edu/~sstoddar
> 
> 
> On Feb 8, 2005, at 10:58 AM, Roger Bivand wrote:
> 
> > On Tue, 8 Feb 2005, Steven T.Stoddard wrote:
> >
> >> I am using GRASS 5.7 and R 2.0 for OS X.  I have a simple xy location 
> >> I
> >> am doing some theoretical work with and would like to import maps into
> >> R using the interface in order to do analyses.  Yet when I attempt to
> >> do this, I get the following error:
> >>
> >>> G<-gmeta()
> >> Error in gmeta() : region for current mapset is invalid
> >> line 11: <top:        100>
> >> run "g.region"
> >>
> >> I traced the problem to the compiled C program that is called from the
> >> gmeta R function (i.e. > .C("gmeta") gives me the same error). I
> >> haven't been able to locate the source code on my volume.
> >>
> >> If I use gmeta(interp = TRUE) there is no problem, until I want to
> >> actually try and import data from my locations.
> >
> > The current fix for 5.7 and 6.0.0beta is to use interp=TRUE. The cause 
> > of
> > the problem seems to be the use of the 3D WINDOW, which the older code 
> > in
> > the R-GRASS interface doesn't yet honour. I'm not at all sure what will
> > happen if your x,y locations are sites; the interface knows about
> > old-style sites, not vector sites. You may be obliged to use 
> > system("") to
> > issue GRASS 5.7 commands to write out an ASCII file to read into R with
> > read.table().
> >
> > Roger
> >
> >
> >>
> >> Any help is appreciated.
> >>
> >> Steve
> >>
> >> ---
> >> Steven T. Stoddard
> >>
> >> Program in Ecology, Evolution and Conservation Biology
> >> University of Illinois at Urbana-Champaign
> >>
> >> (217) 333-2235
> >> 302 Shelford Vivarium
> >> 606 E. Healy Ave
> >> Champaign, IL  61820
> >> http://www.life.uiuc.edu/~sstoddar
> >>
> >>
> >
> > -- 
> > Roger Bivand
> > Economic Geography Section, Department of Economics, Norwegian School 
> > of
> > Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
> > Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
> > e-mail: Roger.Bivand at nhh.no
> >
> >
> 

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Breiviksveien 40, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93
e-mail: Roger.Bivand at nhh.no