UCSC Bin indexing system

[desmo]

Does anyone know how exactly works the Bin indexing system used in the UCSC genome browser?
I found just few words in this webpage http://genomewiki.ucsc.edu/index.php...ndexing_system
but i'm not familiar with java and I'm not able to translate this code in perl.
Any suggestion?
Thanks in advance

[Richard Finney]

See http://plindenbaum.blogspot.it/2010/...ng-genome.html (via http://www.biostars.org/post/show/95...d-by-sam-ucsc/ )

Perl Implementation: No guarantees ...

sub binFromRangeStandard
{
my $zstart;
my $zend;
my $i;
my $startBin;
my $endBin;
my $retval;
my @binOffsets = (512+64+8+1, 64+8+1, 8+1, 1, 0);

$zstart = $_[0];
$zend = $_[1];
$startBin = $zstart;
$endBin = $zend-1;
$startBin = $startBin >> 17;
$endBin = $endBin >> 17;
for ($i=0; $i<5; $i = $i + 1){
if ($startBin == $endBin){
$retval = $binOffsets[$i] + $startBin ;
return $retval;
}

$startBin = $startBin >> 3;
$endBin = $endBin >> 3;
}
$retval = 0;
return $retval;
}

[desmo]

Thanks for your help.
I'll test it as soon as possible. Thanks again