[time-nuts] Perl program for stability analysis available

John Ackermann N8UR jra at febo.com
Fri Dec 31 11:54:19 EST 2004


Hi --

I've put a very preliminary alpha version of a perl program called 
"stable-stats.pl" up on my website.  You can download it from 
http://www.febo.com/time-freq/tools/index.html.  It should run on any 
system capable of running perl, but it does require one external 
statistics module; I have a link to that module on the web page.

stable-stats.pl will read (from standard input) a file containing 
MJD/phase pairs, one pair per line with values separated by spaces or 
tabs.  It will output the drift, the frequency offset based on both 
linear regression and endpoints, and Allen Variance for a reasonable set 
of tau values.

I'll repeat that this is an alpha program with little error checking or 
flexibility.  It also truncates where it ought to round.  I hope to 
fancy it up once I'm sure the basic algorithms are working properly.*  
Based on a limited set of test data, its results seem to reasonably 
match those of Stable32 (though it doesn't do nearly as much as that 
program).

Please feel free to try this out, and particularly to scrutinize the 
code for any errors -- there are plenty of opportunities for off-by-one 
and other indexing errors.  I welcome problem reports, suggestions, and 
bug fixes.

Happy New Year!

John

* On the to-do list are the automatic generation of phase and AVAR 
plots, as well as general robustness and flexibility improvements.




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