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

Thorsten Behrens thor@ten@m@behren@ @end|ng |rom gm@||@com
Tue Apr 28 13:39:15 CEST 2020


Roger and Mike,

I really appreciate your help on this!

I had a look at getRasterData(). It results in the same error. Hence, I 
made further tests where I compared grids with the following numbers of 
cols and rows:

nPx = floor(sqrt(2^31 -1)) # 46340

and

nPx = ceiling(sqrt(2^31 -1)) # 46341

The result is clear. Raster data with 46340 * 46340 px can be loaded 
with getRasterData() and with raster(), raster::as.matrix(), whereas 
datasets with 46341 * 46341 px cannot and result in the error:

Error in getRasterData(gdCeil, band = 1) :
long vectors not supported yet: memory.c:3782

read_stars() works for both. You find the corresponding code below.

Are there any other option I can try?

Thorsten


Reproducible code:

## generate raster datasets
# 46340 * 46340 grid dataset
sFileNameFloor = "Floor.tif"

nPx = floor(sqrt(2^31 -1)) # 46340
nPx

rFloor = raster(nrow = nPx, ncol = nPx, ext = extent(c(0, nPx, 0, nPx)))
values(rFloor) = 1

writeRaster(rFloor, sFileNameFloor, "GTiff", overwrite = TRUE, NAflag = 
-9999)


# 46341 * 46341 grid dataset
sFileNameCeil = "Ceil.tif"

nPx = ceiling(sqrt(2^31 -1))
nPx

rCeil = raster(nrow = nPx, ncol = nPx, ext = extent(c(0, nPx, 0, nPx)))
values(rCeil) = 1

writeRaster(rCeil, sFileNameCeil, "GTiff", overwrite = TRUE, NAflag = 
-9999)


## load raster datasets with different methods

# load Ceil
gdCeil = GDAL.open(sFileNameCeil)
dim(gdCeil)

vnCeil = getRasterData(gdCeil, band = 1) # error

GDAL.close(gdCeil)
str(vnCeil)

stCeil = read_stars(sFileNameCeil) # all fine
str(stCeil[[1]])

rCeil = raster(sFileNameCeil)
mCeil = raster::as.matrix(rCeil) # error
str(mCeil)


# load Floor
gdFloor = GDAL.open(sFileNameFloor)
dim(gdFloor)

vnData = getRasterData(gdFloor, band = 1) # all fine

GDAL.close(gdFloor)
str(vnData)

stFloor= read_stars(sFileNameFloor) # all fine
str(stFloor[[1]])

rFloor = raster(sFileNameFloor)
mFloor = raster::as.matrix(rFloor) # all fine
str(mFloor)




Am 28.04.2020 um 12:10 schrieb Roger Bivand:
> On Tue, 28 Apr 2020, Thorsten Behrens 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.
>
> Not rgdal, but your use of it. Try looking at a sequence of
>
> file <- system.file("pictures/SP27GTIF.TIF", package="rgdal")
> obj <- GDAL.open(file)
> (dims <- dim(obj))
> band <- 1
> data_vector <- getRasterData(obj, band)
> GDAL.close(obj)
> str(data_vector)
>
> This does not create any more complicated objects, just a matrix. In 
> some cases, the rows in the matrix are ordered S -> N, so it may 
> appear the wrong way up.
>
> rgdal::getRasterData() is lightweight, and has many arguments which 
> may be helpful. rgdal::readGDAL() is heavyweight, creating a 
> SpatialGridDataFrame object. This involves much copying of data, but 
> the output object can be used for example in mapping or analysis 
> without further conversion. My guess is that rgdal::getRasterData() 
> gives you your matrix directly. Look at the R code to see how as.is= 
> etc. work (files may include scale and offset values - recently a user 
> was confused that scale and offset were "magically" applied to convert 
> Uint16 values to degrees Kelvin on reading). For example, if as.is == 
> TRUE or scale == 1 and offset == 0, no copying of the input matrix 
> occurs because it is not converted. If you could check this route, 
> others following this thread could also benefit; if I'm wrong, that 
> would also be good to know.
>
> Roger
>
>
>>
>> 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"
>>>    >>
>>>    >> _______________________________________________
>>>    >> R-sig-Geo mailing list
>>>    >> R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>>>    >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>    >>
>>>    >>
>>>    >
>>>
>>>     _______________________________________________
>>>     R-sig-Geo mailing list
>>>     R-sig-Geo using r-project.org <mailto:R-sig-Geo using r-project.org>
>>>     https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>
>>     [[alternative HTML version deleted]]
>>
>> _______________________________________________
>> R-sig-Geo mailing list
>> R-sig-Geo using r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>
>



More information about the R-sig-Geo mailing list