[0]  [1]
[0] chr1 10 
[1] chr3 20 
[2] chr1 30 
[3] chr3 5     
.
.
.
[n] chr5 5  

##</code><code>##

    [0]  [1]
[0] chr1 10 
[1] chr1 30 
[2] chr3 5 
[3] chr3 20     
.
.
.
[n] chr5 5  

##</code><code>##

my @sortedtda;
my @chrnums;
my @coords;
$i=0;

for (@twodarray) {
	push @chrnums, $twodarray[$i][0]=~ (/(\d+)/);
	push @coords,  $twodarray[$i][1]=~ (/(\d+)/);
	++$i;
    }

@sortedtda = @twodarray[ sort {
			$coords[$a] <=> $coords[$b]
				 ||
			$chrnums[$a] <=> $chrnums[$b]
		       } 0..$#twodarray
	       ];