[STATSGRASS] import DTM with readRAST6()

[Carlos "Guâno" Grohmann]

I just tested here in grass 6.2.1 (ubuntu package), it worked fine.

I see you have some very "precise" elevation readings:
370.84381103515625....

and that in the import process, data is exported as double (bytes=8),
maybe this is the problem?

any way you can get that elevations with less decimal values?

just a guess, but..

Carlos






On 7/9/07, Matteo Dall'Amico <matteo.dallamico at ing.unitn.it> wrote:
> Hi Carlos,
> thank you for your reply.
> I think the problem is that the import was not successful. As you see
> from data attributes,
>
> Data attributes:
> DTM_trentino_100m
> Min.   :1.192e-319
> 1st Qu.:1.065e-314
> Median :1.066e-314
> Mean   :1.285e-312
> 3rd Qu.:2.722e-312
> Max.   :4.774e-312
>
> the elevations are not correct. I would expect values ranging between
> 60 and 3500m and not from 1.192e-319 to 4.774e-312.
> I think the problem lays in the import procedure during readRAST6().
> Any suggestion?
> Thanks in advance,
> Matteo
>
> On 9 Jul 2007, at 15:41, Carlos Guâno Grohmann wrote:
>
> > try to
> > str(trentino.grid)
> >
> > the summary() you want is probably
> >
> > summary(trentino.grid$DTM_trentino_100m)
> >
> > hope this helps
> > Carlos
> >
> >
> >
> > On 7/9/07, Matteo Dall'Amico <matteo.dallamico at ing.unitn.it> wrote:
> >>
> >> Hello everybody,
> >> I am a new R & Grass user.
> >> I am interested in doing a kriging of the Temperature in a basin,
> >> based on
> >> pixel elevation (DTM).
> >> I use Grass 6.2.1 and R 2.5.1 and have installed the spgrass6
> >> package.
> >>
> >> The DTM is called "DTM_trentino_100m" and has a header and data
> >> like the
> >> following:
> >>
> >> north:5158000.0
> >> south:5058500.0
> >> east:1729700.0
> >> west:1611600.0
> >> rows:995
> >> cols:1181
> >> -9999.0 -9999.0 -9999.0 370.84381103515625 372.55120849609375
> >> 373.13128662109375 .....
> >>
> >> I have opened R inside the Grass location, and imported the DTM:
> >>
> >> >  trentino.grid<-readRAST6("DTM_trentino_100m")
> >> Creating BIL support files ...
> >> Header File =
> >> /Users/Matteo/Documents/DataGrass/GBovest/Permafrost/.tmp/
> >> nilo.local/DTM_trentino_100m.hdr
> >> World File =
> >> /Users/Matteo/Documents/DataGrass/GBovest/Permafrost/.tmp/
> >> nilo.local/DTM_trentino_100m.wld
> >> Exporting Raster as double values(bytes=8)
> >> Using the Current Region settings ...
> >> north=5158000.000000
> >> south=5058500.000000
> >> east=1729700.000000
> >> west=1611600.000000
> >> r=995
> >> c=1181
> >>
> >> Percent complete:  100%
> >> r.out.bin complete.
> >>
> >> > summary(trentino.grid)
> >> Object of class SpatialGridDataFrame
> >> Coordinates:
> >>               min     max
> >> coords.x1 1611600 1729700
> >> coords.x2 5058500 5158000
> >> Is projected: TRUE
> >> proj4string :
> >> [+proj=tmerc +lat_0=0.0000000000 +lon_0=9.0000000000
> >> +k_0=0.9996000000
> >> +x_0=1500000.0000000000 +y_0=0.0000000000 +a=6378388 +rf=297 +no_defs
> >> +towgs84=-225.000,-65.000,9.000]
> >> Number of points: 2
> >> Grid attributes:
> >>   cellcentre.offset cellsize cells.dim
> >> 1           1611650      100      1181
> >> 2           5058550      100       995
> >> Data attributes:
> >> DTM_trentino_100m
> >> Min.   :1.192e-319
> >> 1st Qu.:1.065e-314
> >> Median :1.066e-314
> >> Mean   :1.285e-312
> >> 3rd Qu.:2.722e-312
> >> Max.   :4.774e-312
> >>
> >> As you can see, the import has been fully done, yet the attributes
> >> are not
> >> correct. In fact, the Min. value is 1.192e-319 and the Max is
> >> 4.774e-312 but
> >> in reality the elevation changes between 60m to 3500m.
> >> Have I done something wrong? What should I do?
> >> Thank you in advance,
> >>
> >> Matteo
> >>
> >>
> >> ---------------------------------
> >> Matteo Dall'Amico
> >> PhD candidate
> >> CUDAM and department of Civil and Environmental Engineering
> >> Universita' degli Studi di Trento
> >> Via Mesiano 77 - 38050 Trento - Italy
> >> email: matteo.dallamico at ing.unitn.it
> >> Tel. +39 0461 882610
> >> Fax +39 0461 882672
> >> http://www.dottorato.it/trento/
> >> ---------------------------------
> >>
> >>
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> >> statsgrass at grass.itc.it
> >> http://grass.itc.it/mailman/listinfo/statsgrass
> >>
> >>
> >
> >
> > --
> > +-----------------------------------------------------------+
> >              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
> >
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> > statsgrass at grass.itc.it
> > http://grass.itc.it/mailman/listinfo/statsgrass
> >
>
>


-- 
+-----------------------------------------------------------+
              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