On Mon, 2009-01-19 at 20:57 +1100, Michael Sumner wrote: > Hello, > Hey Mike,
thanks for your exhaustive answere :-) > Note this recent R-Sig-Geo post about the "in-development" nature of the > latest builds of rgdal - you need to let us know what versions you are > using. Also, view the definition of writeGDAL() to see how the lower > level functions are used. > > https://stat.ethz.ch/pipermail/r-sig-geo/2009-January/004830.html > I have read that message, but my version is not affected be the one Roger refers to: ,---------------------------------- > library(rgdal) Loading required package: sp Geospatial Data Abstraction Library extensions to R successfully loaded Loaded GDAL runtime: GDAL 1.5.2, released 2008/05/29 GDAL_DATA: /usr/local/lib/R/site-library/rgdal/gdal Loaded PROJ.4 runtime: Rel. 4.6.0, 21 Dec 2007 PROJ_LIB: /usr/local/lib/R/site-library/rgdal/proj > sessionInfo() R version 2.7.1 (2008-06-23) i486-pc-linux-gnu locale: LC_CTYPE=en_US.UTF-8;LC_NUMERIC=C;LC_TIME=en_US.UTF-8;\ LC_COLLATE=en_US.UTF-8;LC_MONETARY=C;LC_MESSAGES=en_US.UTF-8;\ LC_PAPER=en_US.UTF-8;LC_NAME=C;LC_ADDRESS=C;LC_TELEPHONE=C;\ LC_MEASUREMENT=en_US.UTF-8;LC_IDENTIFICATION=C attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] rgdal_0.5-33 sp_0.9-29 loaded via a namespace (and not attached): [1] grid_2.7.1 lattice_0.17-20 `---------------------------------- > BTW, you can simplify the writing of GTiffs with writeGDAL() -unless you > are intending to develop your function to write to the file in smaller > pieces. The code to do that can be as simple as this: > library(rgdal) > ## read in matrix to bm > ## . . . > ## generate X/Y coordinates - assuming your matrix is aligned as image() > expects (replace 0 and 1 as needed) > xx <- seq(0, length = nrow(bm), by = 1) > yy <- seq(0, length = ncol(bm), by = 1) > ## > writeGDAL(image2Grid(list(x = xx, y = yy, z = bm)) > That snipped brought my machine »to its knees« .. but that is a problem of R itself (actually, I'm currently exploring). > > But, your R function works for me for the following simple test. As > Frank mentioned, it probably comes down to a version problem or a file > size limit (although that seems unlikely since your input matrix "bm" > must be completely loaded in memory). > > library(rgdal) > #Loading required package: sp > #Geospatial Data Abstraction Library extensions to R successfully loaded > #Loaded GDAL runtime: GDAL 1.6.0, released 2008/12/04 > #Path to GDAL shared files: C:\inst\R\library/rgdal/gdal > #Loaded PROJ.4 runtime: Rel. 4.6.1, 21 August 2008 > #Path to PROJ.4 shared files: C:\inst\R\library/rgdal/proj > > data(volcano) # matrix 87x61 > bm.writeTiff(volcano, "volc.tif") > # used (Mb) gc trigger (Mb) max used (Mb) > #Ncells 305831 8.2 597831 16 407500 10.9 > #Vcells 149194 1.2 786432 6 467409 3.6 > tst <- readGDAL("volc.tif") > > #volc.tif has GDAL driver ltalk X6 > #and has 87 rows and 61 columns > My image got dimension 8950 9790 7, could that dimension be the problem? Regards Henning -- . . . no signature
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