[R-sig-Geo] kriging -- grass -- asciigrid
Jose Funes
jefunes at gmail.com
Mon Mar 3 23:13:18 CET 2008
Rogers,
It worked great, the function writeAsciiGrid() from maptools. My goal
was to export it as Arc ASCII file.
Thanks,
Jose
On Sun, Mar 2, 2008 at 3:51 PM, Roger Bivand <Roger.Bivand at nhh.no> wrote:
> On Fri, 29 Feb 2008, Jose Funes wrote:
>
> > Dear members,
> >
> > I have tried to export a kriging map to arcgis as asciigrid or image.
> > I have used the functions write.asciigrid and writeRast6sp(grass), in
> > both cases any success; In the former when exporting it, I got the
> > following message " Asciigrid does not support grids with non-square
> > cells".
>
> Please quote your exact code. The function writeAsciiGrid() in maptools
> will probably work, while write.asciigrid() in sp (which we ought to
> deprecate, pointing to maptools) does not. The problem is machine fuzz,
> the 90.0 values probably differ by 1e-16 or some other small amount -
> writeAsciiGrid() tests and corrects for the fuzz.
>
>
> > I checked for the krige map topology characteristics using the
> > following code:
> > getGridTopology(lidekri)
> >
> > Apparently cell size looks fine: see below
> >
> > s1 s2
> > cellcentre.offset -363565.9 175563.0
> > cellsize 90.0 90.0
> > cells.dim 804.0 1236.0
> >
> > For the writeRast6sp function from "spgrass6" library
> >
> > writeRast6sp(lidekri,"lidekri",zcol="var1.pred",NODATA=-9999),
> >
>
> Was your goal to write an Arc ASCII grid as a file, or to write the data
> to GRASS?
>
> Did you try writeRAST6() in spgrass6, which uses other file formats?
>
> Did you try the Arc ASCII grid driver "AAIGrid" with writeGDAL() in rgdal?
>
> Hope this helps,
>
> Roger
>
>
>
> > I got the following message error
> >
> > "Error in system(paste(paste("g.tempfile", .addexe(), sep = ""),
> > "pid=", : g.tempfilepid=421 not found"
> >
> > I will greatly appreciate any suggestions to get around this technical problem.
> >
> > Sincerely,
> >
> > Jose Funes
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Fri, Feb 29, 2008 at 6:00 AM, <r-sig-geo-request at stat.math.ethz.ch> wrote:
> >> Send R-sig-Geo mailing list submissions to
> >> r-sig-geo at stat.math.ethz.ch
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> >>
> >> When replying, please edit your Subject line so it is more specific
> >> than "Re: Contents of R-sig-Geo digest..."
> >>
> >>
> >> Today's Topics:
> >>
> >> 1. estimates for paths of travel given two time series, drawn
> >> from two corresponding spatial densities (Galkowski, Jan)
> >> 2. makeGrid(PBSmapping) (Markus Loecher)
> >> 3. Choice of Spatial weights (stefan lhachimi)
> >>
> >>
> >> ----------------------------------------------------------------------
> >>
> >> Message: 1
> >> Date: Thu, 28 Feb 2008 13:58:49 -0500
> >> From: "Galkowski, Jan" <jgalkows at akamai.com>
> >> Subject: [R-sig-Geo] estimates for paths of travel given two time
> >> series, drawn from two corresponding spatial densities
> >> To: <r-sig-geo at stat.math.ethz.ch>
> >> Message-ID:
> >> <76EB4827B2104D40AE7E43AA5D8582EA011A9D32 at MAVS1.kendall.corp.akamai.com>
> >>
> >> Content-Type: text/plain
> >>
> >> This is less an R question and more a request to the community for
> >> literature references and the like.
> >>
> >> I'm interested in the following inferential question. What's the max
> >> likelihood estimate for a path of travel of a point across a plane
> >> having stable, smooth densities of two separate variables given two time
> >> series of their values at the point as it moves? Suppose all that's
> >> available is the ratio of the variables?
> >>
> >> This is motivated by problems of inferring movement of biological
> >> specimens between nesting and migratory regions, or the problem of
> >> recovery of travel given the technique described here:
> >>
> >> http://www.pnas.org/cgi/content/abstract/105/8/2788
> >>
> >> Despite that, are there R packages which might help this? I ask because
> >> I often find real gems buried within many R packages, gems which aren't
> >> obviously related to their primary subject.
> >>
> >> Thanks much.
> >>
> >> [[alternative HTML version deleted]]
> >>
> >>
> >>
> >> ------------------------------
> >>
> >> Message: 2
> >> Date: Thu, 28 Feb 2008 15:00:28 -0500
> >> From: Markus Loecher <loecher at eden.rutgers.edu>
> >> Subject: [R-sig-Geo] makeGrid(PBSmapping)
> >> To: r-sig-geo at stat.math.ethz.ch
> >> Message-ID: <20080228195805.F18A632408E at annwn13.rutgers.edu>
> >> Content-Type: text/plain; charset="us-ascii"; format=flowed
> >>
> >> Dear geo experts,
> >> I am clearly misunderstanding the role of the projection argument in
> >> the wonderful utility makeGrid(PBSmapping).
> >> I had hoped that by setting projection ="LL" the resulting grid would
> >> be equidistant in "real" space, and hence curvilinear in lat/lon space.
> >> But the following code yields the identical, regular grid,
> >> irrespective of the projection argument:
> >>
> >> mypolys <- makeGrid(x= seq(-123,-122,length=10), y = seq(33, 34,
> >> length=10), byrow = FALSE, addSID = TRUE, projection = "LL")
> >> plotMap(mypolys)
> >> mypolys <- makeGrid(x= seq(-123,-122,length=10), y = seq(33, 34,
> >> length=10), byrow = FALSE, addSID = TRUE, projection = 1)
> >> plotMap(mypolys)
> >>
> >> Is there an easy way to create a rectangular grid in lat/lon space ?
> >> Should I first translate the points to UTM coordinates ?
> >>
> >> Thanks!
> >>
> >> Markus
> >>
> >>
> >>
> >> ------------------------------
> >>
> >> Message: 3
> >> Date: Fri, 29 Feb 2008 11:36:18 +0100
> >> From: "stefan lhachimi" <stefan.duke at gmail.com>
> >> Subject: [R-sig-Geo] Choice of Spatial weights
> >> To: r-sig-geo at stat.math.ethz.ch
> >> Message-ID:
> >> <a211af3b0802290236m53a12cd1h806a3106f508fb54 at mail.gmail.com>
> >> Content-Type: text/plain; charset=ISO-8859-1
> >>
> >> Dear all,
> >>
> >> as a matter of curiosity does anybody know literature which discusses
> >> what spatial weight to choose (e.g. k-nn, single or double
> >> contiguity)? Or has anybod a good rule of thumb?
> >> I found an article which proposes to try several specification and
> >> take either the one with the highest lambda or the one with the best
> >> overall model fit (in a regression). But I think that is statistically
> >> speaking that is not very satisfactory, in particular if the
> >> application does not give any indication what weight to use.
> >>
> >> Any hints?
> >> Best,
> >> Stefan
> >>
> >>
> >>
> >> ------------------------------
> >>
> >> _______________________________________________
> >> R-sig-Geo mailing list
> >> R-sig-Geo at stat.math.ethz.ch
> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >>
> >> End of R-sig-Geo Digest, Vol 54, Issue 27
> >> *****************************************
> >>
> >
> > _______________________________________________
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> > R-sig-Geo at stat.math.ethz.ch
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
>
> --
> Roger Bivand
> Economic Geography Section, Department of Economics, Norwegian School of
> Economics and Business Administration, Helleveien 30, N-5045 Bergen,
> Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
> e-mail: Roger.Bivand at nhh.no
>
>
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