[R-sig-Geo] rgdal: problem reading a bigger raster dataset (R 4.0.0/3.6.3, Ubuntu 20.04)

Michael Sumner md@umner @end|ng |rom gm@||@com
Tue Apr 28 12:12:46 CEST 2020


I reckon that's unlikely, it's also unlikely to scale or be fast enough
ever  given what rgdal is - raster will happily crop sections of it out but
I guess your workflow is to write the geotiff out in one go? You want rgdal
because you want raster?  Have you tried terra? (I forgot to mention that
one, and I haven't tried on that size GeoTIFF with it. It has its own
internal connection to GDAL).

Possibly you can instantiate a GeoTIFF with rgdal of the right size, then
write to it piecewise - but if the convenience of raster is what you're
after that's obviously no good. I think I'm missing some workflow
constraint or motivation you have, but I'm interested (it's an awkward
space).

Cheers, Mike

On Tue, Apr 28, 2020 at 7:14 PM Thorsten Behrens <
thorsten.m.behrens using gmail.com> wrote:

> Michael,
>
> Thanks for the hint, it seems to work! Real-world tests will follow in
> the next few days...
>
> So it definitely seems to be a problem of rgdal. It would be great if it
> could still be solved.
>
> Best,
>
> Thorsten
>
>
>
> Am 27.04.2020 um 15:58 schrieb Michael Sumner:
> > Try stars it worked for me on a test
> >
> > On Mon., 27 Apr. 2020, 23:54 Thorsten Behrens,
> > <thorsten.m.behrens using gmail.com <mailto:thorsten.m.behrens using gmail.com>>
> > wrote:
> >
> >     Roger,
> >
> >     thanks a lot for your reply!
> >
> >     I have 256GB RAM installed (mentioned it somewhere). And there,
> >     all is
> >     fine when I run:
> >
> >     rDemTest = raster(nrow = 48000, ncol = 72000, ext = extent(c(0,
> 72000,
> >
> >     values(rDemTest) = 1
> >
> >     When limiting the memory to about 8GB with
> >     ulimit::memory_limit(8000),
> >     the max size which can be allocated seems to be around 10000 x
> >     10000px.
> >     In this case all tests run fine. Unfortunately it seems to be
> >     related to
> >     the size of the grid (48000 x 72000) and therefore the problem
> >     can't be
> >     reproduced on machines with 8GB RAM. For some processing steps I need
> >     grids of that size in the memory, which is why I have 256 GB
> >     installed.
> >
> >     Normally, I use the raster package and not rgdal::readGDAL(). This
> >     was
> >     just a desperate attempt to find the source of the problem.
> >
> >     This is what I use in my code:
> >
> >     rDem = raster(sFileNameTiff)
> >     mDem = raster::as.matrix(rDem)
> >
> >     But maybe this is the same...
> >
> >     Any further suggestions are much appreciated!
> >
> >     Thanks again!
> >
> >     Best,
> >
> >     Thorsten
> >
> >
> >
> >
> >     Am 27.04.2020 um 14:50 schrieb Roger Bivand:
> >     > On Mon, 27 Apr 2020, Thorsten Behrens wrote:
> >     >
> >     >> Dear all,
> >     >>
> >     >> my problem is that I want to read a big geotiff raster dataset
> >     into R
> >     >> and convert it to a matrix, which does not work.
> >     >> The file is big but there is sufficient memory. I need all the
> >     data
> >     >> in the memory at the same time.
> >     >>
> >     >> The error occurs under R 3.6.3 as well as 4.0.0 using Ubuntu 20.04
> >     >> LTS with the latest version of the packages (see session info
> >     below)
> >     >> and 256GB RAM installed.
> >     >>
> >     >> When loading the raster dataset using rgdal (via readGDAL or
> >     >> raster::readAll) I get the follwoing error in R 4.0.0:
> >     >>
> >     >> ```
> >     >> Error in rgdal::getRasterData(con, offset = offs, region.dim =
> >     reg,
> >     >> band = object using data@band) :
> >     >>   long vectors not supported yet: memory.c:3782
> >     >> ```
> >     >
> >     > On a 16GB Fedora platform:
> >     >
> >     >> library(raster) # 3.1-5
> >     >> rDemTest = raster(nrow = 48000, ncol = 72000, ext = extent(c(0,
> >     72000,
> >     > 0,
> >     > + 48000))) # all fine
> >     >> rDemTest
> >     > class      : RasterLayer
> >     > dimensions : 48000, 72000, 3.456e+09  (nrow, ncol, ncell)
> >     > resolution : 1, 1  (x, y)
> >     > extent     : 0, 72000, 0, 48000  (xmin, xmax, ymin, ymax)
> >     > crs        : NA
> >     >
> >     >> values(rDemTest) = 1
> >     > Error: cannot allocate vector of size 25.7 Gb
> >     >
> >     > So you are deceiving yourself into thinking that all is fine at
> >     this
> >     > point. Please try to instantiate an example that can be
> >     reproduced on
> >     > a machine with 8GB RAM.
> >     >
> >     > Further note that rgdal::readGDAL() is not how you handle very
> >     large
> >     > objects in files, and never has been. raster can handle blocks
> >     of data
> >     > from bands in file; stars and gdalcubes can use proxy=TRUE for the
> >     > same purpose. Why did you choose rgdal::readGDAL() when this is not
> >     > its purpose?
> >     >
> >     > You did not say how much RAM is on your platform.
> >     >
> >     > Roger
> >     >
> >     >>
> >     >> In R 3.6.3 is is "... memory.c:3717"
> >     >>
> >     >> However, I can load the same file with the tiff package and a
> >     file of
> >     >> the same size in the native raster package format (*.grd) with the
> >     >> raster package but again not with the rgdal package.
> >     >>
> >     >> gdalinfo (gdalUtils) does not complain (see below). Hence, Even
> >     >> Rouault assumes the problem is related to rgdal and not gdal
> >     >> (https://github.com/OSGeo/gdal/issues/2442).
> >     >>
> >     >> Below you find reproducible code, which generates a raster file,
> >     >> saves the two formats (.tiff and .grd) and tries to read them with
> >     >> the different packages.
> >     >>
> >     >> Is this a known limitation? Any help is greatly appreciated!
> >     >>
> >     >> Thanks a lot in advance!
> >     >>
> >     >> Best wishes and stay healthy,
> >     >> Thorsten
> >     >>
> >     >>
> >     >>
> >     >> ### Steps to reproduce the problem.
> >     >>
> >     >> R code:
> >     >>
> >     >> ```
> >     >> library(rgdal) # 1.4-8
> >     >> library(raster) # 3.1-5
> >     >> library(tiff) # 0.1-5
> >     >>
> >     >> ## generate and manipulate a big raster dataset
> >     >> # - generate
> >     >> rDemTest = raster(nrow = 48000, ncol = 72000, ext = extent(c(0,
> >     >> 72000, 0, 48000))) # all fine
> >     >>
> >     >> # - manipulate
> >     >> values(rDemTest) = 1 # all fine
> >     >>
> >     >> # - convert
> >     >> mDemTest = raster::as.matrix(rDemTest) # all fine
> >     >> str(mDemTest)
> >     >>
> >     >> ## save a big dataset
> >     >>
> >     >> # - as raster/gdal
> >     >> sFileNameTiff = "BigData.tif"
> >     >> writeRaster(rDemTest, sFileNameTiff, "GTiff", overwrite = TRUE,
> >     >> NAflag = -9999) # all fine
> >     >>
> >     >> # - as raster native
> >     >> sFileNameNative = "BigData.grd"
> >     >> writeRaster(rDemTest, sFileNameNative, "raster", overwrite = TRUE,
> >     >> NAflag = -9999) # all fine
> >     >>
> >     >>
> >     >> ## load the big raster datasets with different packages and
> options
> >     >> # - load the tiff data with the gdal package via the raster
> package
> >     >> rDem = raster(sFileNameTiff) # all fine
> >     >> extent(rDem) # all fine
> >     >> mDem = raster::as.matrix(rDem) # error
> >     >> rDem = readAll(rDem) # error
> >     >>
> >     >> # - load the native raster data with the raster package
> >     >> rDem = raster(sFileNameNative) # all fine
> >     >> extent(rDem) # all fine
> >     >> mDem = raster::as.matrix(rDem) # all fine
> >     >> str(mDem)
> >     >>
> >     >> # - load the tiff data with the tiff package
> >     >> mDem = readTIFF(sFileNameTiff) # all fine
> >     >> str(mDem)
> >     >>
> >     >> # - load the tiff data with the gdal package
> >     >> sfDem = readGDAL(sFileNameTiff) # error
> >     >>
> >     >> # - load the native raster data with the gdal package
> >     >> sfDem = readGDAL(sFileNameNative) # error
> >     >>
> >     >> ```
> >     >>
> >     >>
> >     >> ### Startup messages when rgdal is attached (requested by Roger
> >     Bivand)
> >     >>>  library(rgdal)
> >     >> rgdal: version: 1.4-8, (SVN revision 845)
> >     >>  Geospatial Data Abstraction Library extensions to R
> >     successfully loaded
> >     >>  Loaded GDAL runtime: GDAL 3.0.4, released 2020/01/28
> >     >>  Path to GDAL shared files:
> >     >>  GDAL binary built with GEOS: TRUE
> >     >>  Loaded PROJ.4 runtime: Rel. 6.3.1, February 10th, 2020,
> >     [PJ_VERSION:
> >     >> 631]
> >     >>  Path to PROJ.4 shared files: (autodetected)
> >     >>  Linking to sp version: 1.4-1
> >     >>
> >     >>
> >     >> ### Session info
> >     >>>  sessionInfo()
> >     >> R version 4.0.0 (2020-04-24)
> >     >> Platform: x86_64-pc-linux-gnu (64-bit)
> >     >> Running under: Ubuntu 20.04 LTS
> >     >>
> >     >> Matrix products: default
> >     >> BLAS: /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
> >     >> LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3
> >     >>
> >     >> locale:
> >     >>  [1] LC_CTYPE=de_DE.UTF-8       LC_NUMERIC=C LC_TIME=de_DE.UTF-8
> >     >>  [4] LC_COLLATE=de_DE.UTF-8 LC_MONETARY=de_DE.UTF-8
> >     >> LC_MESSAGES=de_DE.UTF-8
> >     >>  [7] LC_PAPER=de_DE.UTF-8       LC_NAME=C LC_ADDRESS=C
> >     >> [10] LC_TELEPHONE=C LC_MEASUREMENT=de_DE.UTF-8
> >     >> LC_IDENTIFICATION=C
> >     >>
> >     >> attached base packages:
> >     >> [1] stats     graphics  grDevices utils     datasets methods base
> >     >>
> >     >> other attached packages:
> >     >> [1] gdalUtils_2.0.3.2 rgdal_1.4-8       tiff_0.1-5 raster_3.1-5
> >     >> sp_1.4-1
> >     >>
> >     >> loaded via a namespace (and not attached):
> >     >>  [1] compiler_4.0.0    tools_4.0.0       Rcpp_1.0.4.6
> >     >> R.methodsS3_1.8.0 codetools_0.2-16
> >     >>  [6] grid_4.0.0        iterators_1.0.12 foreach_1.5.0
> >     >> R.utils_2.9.2     R.oo_1.23.0
> >     >> [11] lattice_0.20-41
> >     >>
> >     >>
> >     >> ### gdalInfo
> >     >>>  gdalinfo(sFileNameTiff)
> >     >>  [1] "Driver: GTiff/GeoTIFF"
> >     >>  [2] "Files: BigData.tif"
> >     >>  [3] "Size is 72000, 48000"
> >     >>  [4] "Origin = (0.000000000000000,48000.000000000000000)"
> >     >>  [5] "Pixel Size = (1.000000000000000,-1.000000000000000)"
> >     >>  [6] "Image Structure Metadata:"
> >     >>  [7] "  COMPRESSION=LZW"
> >     >>  [8] "  INTERLEAVE=BAND"
> >     >>  [9] "Corner Coordinates:"
> >     >> [10] "Upper Left  (       0.000,   48000.000) "
> >     >> [11] "Lower Left  (   0.0000000,   0.0000000) "
> >     >> [12] "Upper Right (   72000.000,   48000.000) "
> >     >> [13] "Lower Right (   72000.000,       0.000) "
> >     >> [14] "Center      (   36000.000,   24000.000) "
> >     >> [15] "Band 1 Block=72000x1 Type=Float32, ColorInterp=Gray"
> >     >> [16] "  Min=1.000 Max=1.000 "
> >     >> [17] "  Minimum=1.000, Maximum=1.000, Mean=nan, StdDev=nan"
> >     >> [18] "  NoData Value=-9999"
> >     >> [19] "  Metadata:"
> >     >> [20] "    STATISTICS_MAXIMUM=1"
> >     >> [21] "    STATISTICS_MEAN=nan"
> >     >> [22] "    STATISTICS_MINIMUM=1"
> >     >> [23] "    STATISTICS_STDDEV=nan"
> >     >>
> >     >> _______________________________________________
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> >     >>
> >     >>
> >     >
> >
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-- 
Michael Sumner
Software and Database Engineer
Australian Antarctic Division
Hobart, Australia
e-mail: mdsumner using gmail.com

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