[STATSGRASS] speed of GRASS/R interface

[Carlos "Guâno" Grohmann]

Thanks for the quick reply, Augustin.

I am doing a multi-scale study of surface roughness. So I have 180 rasters,
created using 3 different methods, 5 different resolutions, and with 12
moving-window sizes. In R, I am importing the data to produce histograms,
density plots and so on. More as a summary statistics tool than really
analysis. In R I can plot density curves for various maps in one graphic,
and see what is the behaviour of the morphometric variable when resolution
or moving-window size changes.


Carlos




On 10/2/07, Agustin Lobo <Agustin.Lobo at ija.csic.es> wrote:
>
> It makes sense, R puts everything in memory.
> In general, unless you have small raster layers,
> the best is to use the gis for the processing, get
> intermediate data out of the raster and process these data in R.
> Then back to gis for displaying if required.
> In other words, no way of using R instead of r.mapcalc
> unless the raster is very small.
>
> If you can let us know what you want to do with the raster
> we can try to be more specific on how a combined use of grass/r could
> solve the problem (hopefully).
>
> Agus
>
> Carlos "Guâno" Grohmann escribió:
> > I've been thinking about the time it takes to import a raster from GRASS
> > to R. I have some rasters with about 2000 rows and 2500 columns.
> > importing starts fine, creates the header, then goes to 100%, and it
> > hangs there for about 10 minutes, before get ready for the next command.
> > Any way of decrease this waiting time?
> >
> > cheers
> >
> > Carlos
> >
> > --
> > +-----------------------------------------------------------+
> >               Carlos Henrique Grohmann - Guano
> >   Visiting Researcher at Kingston University London - UK
> >   Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
> > Linux User #89721  - carlos dot grohmann at gmail dot com
> > +-----------------------------------------------------------+
> > _________________
> > "Good morning, doctors. I have taken the liberty of removing Windows 95
> > from my hard drive."
> > --The winning entry in a "What were HAL's first words" contest judged by
> > 2001: A SPACE ODYSSEY creator Arthur C. Clarke
> >
> > Can't stop the signal.
> >
> >
> > ------------------------------------------------------------------------
> >
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> >
>
> --
> Dr. Agustin Lobo
> Institut de Ciencies de la Terra "Jaume Almera" (CSIC)
> LLuis Sole Sabaris s/n
> 08028 Barcelona
> Spain
> Tel. 34 934095410
> Fax. 34 934110012
> email: Agustin.Lobo at ija.csic.es
> http://www.ija.csic.es/gt/obster
>



-- 
+-----------------------------------------------------------+
              Carlos Henrique Grohmann - Guano
  Visiting Researcher at Kingston University London - UK
  Geologist M.Sc  - Doctorate Student at IGc-USP - Brazil
Linux User #89721  - carlos dot grohmann at gmail dot com
+-----------------------------------------------------------+
_________________
"Good morning, doctors. I have taken the liberty of removing Windows 95 from
my hard drive."
--The winning entry in a "What were HAL's first words" contest judged by
2001: A SPACE ODYSSEY creator Arthur C. Clarke

Can't stop the signal.
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