Thank you for your help!
I have finished my task.
Best regards.
2010/10/28 Robert J. Hijmans <r.hijm...@gmail.com>
> Hi Mike,
>
> Thanks for that suggestion, It had not occurred to me to overload
> as.matrix. Done that now (raster version 1.6-7) such that
> as.matrix(projras) works.
>
> Best, Robert
>
>
> On Wed, Oct 27, 2010 at 4:01 PM, Michael Sumner <mdsum...@gmail.com>
> wrote:
> > Thanks Robert, I still haven't explored raster enough.
> >
> > I tried as.matrix(projras) - have you considered adding methods like
> > this? I'm afraid I still don't know the structure of the raster data
> > sets enough to know if that makes sense, but I think sp returns
> > another orientation in this way:
> >
> > as.matrix(spprojras)
> >
> >
> > Cheers, Mike.
> >
> > On Thu, Oct 28, 2010 at 9:54 AM, Robert J. Hijmans <r.hijm...@gmail.com>
> wrote:
> >> After this:
> >>
> >>> projras <- projectRaster(r0, pr)
> >>
> >> You could also do plot(projras) or image(projras) and
> >>
> >> v <- getValues(projras, format='matrix')
> >>
> >> To get a matrix of values, with the advantage that values in this
> >> matrix are organized as on the map (probably what you would expect),
> >> which is different in matrix 'm' in Mike's example.
> >>
> >> Robert
> >>
> >> On Wed, Oct 27, 2010 at 2:16 PM, Michael Sumner <mdsum...@gmail.com>
> wrote:
> >>> This is a dummy example - especially in terms of made up coordinate
> >>> system details, but shows how you can reproject with the raster
> >>> package:
> >>>
> >>> library(rgdal)
> >>>
> >>> ## create a grid, with dummy coordinates / projection
> >>>
> >>> im <- image2Grid(list(x = 1e5 * (1:nrow(volcano)), y = 1e5 *
> >>> (1:ncol(volcano)), z = volcano), p4 = "+proj=laea")
> >>>
> >>> writeGDAL(im, "dummy.tif")
> >>>
> >>> ## now the process, using raster package
> >>>
> >>> library(raster)
> >>>
> >>>
> >>> r0 <- raster("dummy.tif")
> >>>
> >>> # proj.4 projection description
> >>> newproj <- "+proj=longlat +ellps=WGS84"
> >>>
> >>> pr <- projectExtent(r0, newproj)
> >>> ## (optionally) Adjust the cell size
> >>> ## res(pr) <- res(pr)/2
> >>>
> >>>
> >>> # project the values of RasterLayer 'r' to the new RasterLayer
> 'projras'
> >>> projras <- projectRaster(r0, pr)
> >>>
> >>> ## now go back to sp and extract matrix
> >>>
> >>> spprojras <- as(projras, "SpatialGridDataFrame")
> >>>
> >>> m <- as.image.SpatialGridDataFrame(spprojras)$z
> >>>
> >>> image(m)
> >>>
> >>>
> >>> I'm not sure if the coercion to SpatialGridDataFrame will
> >>> automatically give you all of the detail in the source by default for
> >>> large grids, but there would be a way.
> >>>
> >>> Cheers, MIke.
> >>> On Wed, Oct 27, 2010 at 7:03 PM, <fsan...@ujaen.es> wrote:
> >>>> Dear R community,
> >>>>
> >>>> I'm sorry, but I am newbie with GIS. I have to import a tiff using a
> >>>> geotiff tool, and convert it into a data matrix. The initial
> projection is
> >>>> Lambert Azimuthal Equal Area, and I would like to get the final matrix
> in
> >>>> a regular lat/lon grid.
> >>>>
> >>>> It is possible to do it with R?
> >>>>
> >>>> Thanks in advance.
> >>>>
> >>>> _______________________________________________
> >>>> R-sig-Geo mailing list
> >>>> R-sig-Geo@stat.math.ethz.ch
> >>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>>>
> >>>
> >>>
> >>>
> >>> --
> >>> Michael Sumner
> >>> Institute for Marine and Antarctic Studies, University of Tasmania
> >>> Hobart, Australia
> >>> e-mail: mdsum...@gmail.com
> >>>
> >>> _______________________________________________
> >>> R-sig-Geo mailing list
> >>> R-sig-Geo@stat.math.ethz.ch
> >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>>
> >>
> >> _______________________________________________
> >> R-sig-Geo mailing list
> >> R-sig-Geo@stat.math.ethz.ch
> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >
> >
> >
> > --
> > Michael Sumner
> > Institute for Marine and Antarctic Studies, University of Tasmania
> > Hobart, Australia
> > e-mail: mdsum...@gmail.com
> >
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo@stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
[[alternative HTML version deleted]]
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
