Issue with rgrass7 and readRAST

Tom

On Fri, 10 Jul 2020, Thomas Adams wrote:

Hi,

I'm using R in combination with GRASS GIS 7.8.3, attempting to read a

GRASS

raster file into R with the rgrass7 interface. I have done this kind of
thing countless times previously without problems. It's quite possible I

am

running into memory issues, but my Ubuntu 18.04 Linux computer has 32 GB

of

RAM.

I have not succeeded in reproducing this, I'm afraid. I created a location
with cell counts to match, and ran r.out.bin first to check whether there
were any issues writing the data to a temporary file. Then I ran the
equivalent of your command (readRAST()), again without problems. I'm on a
16 GB PC, so the problem is puzzling. I'm curious about the free space on
your

/media/teaiii/development/grass/greensboro_mercator/teaiii/.tmp/
teaiii-Leopard-WS

directory. Did you check whether any output arrived there, since the error
message is coming from r.out.bin?

The error is on line 53 in raster/r.out.bin/main.c, when the system
function fwrite() returns an error.

Thanks for your patience.

Roger

My GRASS raster file:

Type of Map:  raster               Number of Categories: 0
Data Type:    CELL
Rows:         22663
Columns:      28794
Total Cells:  652558422
~90m resolution

Using...

srtm <- readRAST("mozambique_srtm_patch",cat=FALSE)

After quite some time, I get...

Error in execGRASS("r.out.bin", flags = rOutBinFlags, input = vname[i],

:

 The command:
r.out.bin -b -i input=mozambique_srtm_patch

output=/media/teaiii/development/grass/greensboro_mercator/teaiii/.tmp/teaiii-Leopard-WS/mozambique_srtm_patch

bytes=4 null=-81
produced an error (1) during execution:
Creating BIL support files...
Exporting raster as integer values (bytes=4)
ERROR: Error writing data
In addition: Warning messages:
1: In showSRID(uprojargs, format = "PROJ", multiline = "NO") :
 Discarded ellps unknown in CRS definition: +proj=merc +lat_ts=0 +lon_0=0
+x_0=0 +y_0=0 +R=6378137 +units=m +no_defs
2: In showSRID(uprojargs, format = "PROJ", multiline = "NO") :
 Discarded datum unknown in CRS definition

Libraries loaded include: sp, rgrass7, rgdal, raster...

Any thoughts?

Best,
Tom

--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; e-mail: Roger.Bivand at nhh.no
https://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en