[GRASS5] r.lzw2z updated...

[Eric G . Miller]

On Tue, Jan 23, 2001 at 09:42:47AM +0000, Markus Neteler wrote:
[snip]
> Processing pcurv at hude ... Copying ... Done!
> WARNING: No lzw_compression_bits value in
>          /home/neteler/grassdata5/hude/hude/cell_misc/tcurv/f_format
> Skipping raster tcurv at hude -- Not LZW compressed
> WARNING: No lzw_compression_bits value in
>          /home/neteler/grassdata5/hude/hude/cell_misc/mcurv/f_format
> Skipping raster mcurv at hude -- Not LZW compressed
> WARNING: No lzw_compression_bits value in
>          /home/neteler/grassdata5/hude/hude/cell_misc/pcurv_rst/f_format
> Skipping raster pcurv_rst at hude -- Not LZW compressed
> 
> The files with WARNING now have a f_format entry like this:
> more f_format 
> type: float
> byte_order: xdr
> lzw_compression_bits: 0
> 
> What does this indicate? Was it an uncompressed file (the map was generated 
> with s.surf.rst) ? 
> The map is corrupted now:
> d.rast tcurv
> WARNING: error reading compressed map [tcurv] in mapset [hude], row 91
> 
> Maybe that's the last bug...

Try changing the lzw_compression_bits to something like "9" and
re-running the r.lzw2z script.  Note: r.lzw2z wouldn't have touch the
f_format file (except to read) if it said it skipped the file.  The
problem seems to be that somehow s.surf.rst writes an lzw compressed
file but lzw_compression_bits is not set correctly (should be between 9
and 20).  Not sure how that would happen.  The reason to have these
tests of lzw_compression_bits is so the program doesn't even try to read
non-LZW compressed rasters (which would always fail and cause the
program to exit).  But, then it has to rely on lzw_compression_bits
being set to a valid value in order to make the determination (it seems
to be the only indicator of LZW compression).  The maps are probably not
corrupted, just LZW compressed with a bogus lzw_compression_bits number.

-- 
Eric G. Miller <egm2 at jps.net>

---------------------------------------- 
If you want to unsubscribe from GRASS Development Team mailing list write to:
minordomo at geog.uni-hannover.de with
subject 'unsubscribe grass5'