#3622: r.out.gdal export in USGSDEM format takes very long time and finally
crashes
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Reporter: dido | Owner: grass-dev@…
Type: defect | Status: new
Priority: critical | Milestone:
Component: Raster | Version: 7.4.0
Resolution: | Keywords: r.out.gdal export USGSDEM long time
| crashes
CPU: x86-64 | Platform: MSWindows 7
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Comment (by dnewcomb):
Are you shooting for the ASCII USGSDEM format as described at
https://www.gdal.org/frmt_usgsdem.html?
From the message:
>Driver <USGSDEM> does not support direct writing. Using MEM driver for
intermediate >dataset.
Do you have enough memory to hold a 4 billion pixel raster in memory on
the computer?
See also
https://www.gdal.org/frmt_mem.html
Not sure if either the MEM driver or the USGS DEM format can handle 4
billion pixels. Is there a reason that you can't use GeoTIFF ( up to 4GB
file Size)for the output file or GeoTIFF with the BIGTIFF option? ( up to
18,000 petabytes for a single file)
If you are determined to do ascii file output, why not r.out.ascii,
https://grass.osgeo.org/grass74/manuals/r.out.ascii.html ?
>WARNING: Precision loss: Raster map
<BGMdem_8x8m_holes_filled_feathered@PERMANENT> of >type DCELL to be
exported as Int16. This can be avoided by using Float64.
If you are going to truncate to integer, it might be better to use the
int() or round() functions in r.mapcalc prior to exporting.
--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3622#comment:1>
GRASS GIS <https://grass.osgeo.org>
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