[fitsbits] neural net default choice of compression algorithm? Was: Re: Rice compression from the command line

Boud Roukema boud at astro.uni.torun.pl
Thu Jul 20 06:57:20 EDT 2006


hi all,

On Thu, 20 Jul 2006, Mark Calabretta wrote:

> For the freedb database 7zip compresses 30% better than gzip and
> decompresses *faster* than gzip in elapsed time.  The 11-fold increase
> in compression time would be amortized via repeated accesses to the
> database. 
> 
> The bottom line is to use the technology that best suits the task.

Just throwing ideas around: it could be possible to make a simple neural
net algorithm, or even just write a small handful of if-then statements,
which automatically chooses a default algorithm likely to be most useful
for the particular type of data in a fits file, based on the FITS keywords.
Or it could be something like the bayesian filter usable in spamassassin and 
so on, e.g. words like "dome flat" or "flat field" in description headers
or whether or not the data are integer or floats, seem to give differences
based on the previous few days' discussion on what are likely to be 
preferable algorithms.

Of course, it would need to be possible to override the default which
is recommended by this algorithm-for-choosing-algorithms. And it
depends at what level "user" we want to be friendly with. On the other
hand, it may not be worth the effort put in to write it (and i'm not
volunteering)...

al-khawarizmical greetings
boud



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