#
#	Evaluate the complexity of a sequence in bits per symbol by
#	computing its compressed form.
#
#	This is a trivial measure and depends on the underlying system
#	being able to run gzip -9 <filename>
#
#	Result: average number of bits per symbol.
#
#	A poor-man's complexity measure
#
#	Gaston H. Gonnet (Oct 17th, 2012)
#
SequenceComplexity := proc( s:string )
if length(s) < 5 then
    error(s,'string is too short to evaluate its complexity') fi;
tmpfile := tmp70q987015au . Rand(1e8..1e9);
OpenWriting( tmpfile );
printf( '%s', s );
OpenWriting( 'previous' );
t := TimedCallSystem( 'gzip -9c ' . tmpfile );
CallSystem( 'rm -f ' . tmpfile );
if t[1] <> 0 then error('compression command failed') fi;
(length(t[2])-42)*8/length(s)
end: