[GRASS-dev] seemingly random errors in r.mapcalc

[Glynn Clements]

Paulo van Breugel wrote:

> Sorry, pushed the short cut sending the email off too early.. What I wanted
> to ask is, is there any way I can find out what kind of error I am getting?
> Now, the only message is "Error".

There are only a few possible causes of "Error reading raster data",
namely an error from lseek(), read(), G_zlib_read() or GDALRasterIO(),
or a short count returned from read().

Any of these can be caused by corrupted data, but that would normally
be repeatable.

G_zlib_read() is only applicable to floating-point maps, while
GDALRasterIO() is only applicable to GDAL-linked maps (r.external).

If it's a hardware error, it will be logged by the kernel. The log
files are usually in /var/log, but which errors go in which files
depends upon the distribution.

If you're compiling from source, be sure to run "make clean" between
"svn update" and "make". Incremental compilation isn't reliable in the
general case. If "svn update" updates the configure script, be sure to
re-run configure before doing anything else.

-- 
Glynn Clements <glynn at gclements.plus.com>