A   R   N   D   *
A    4  -1  -2  -2  -2  
R   -1   5   0  -2  -2 
N   -2   0   6   1  -2
D   -2  -2   1   6  -2
*   -2  -2  -2  -2   4

my data structure sees like this:
$VAR1 = {
          'A' => {
                   'A' => 4,
                   'R' => -1,
                   'N' => -2,
                   'D' => -2,
                   },
         'R' => {'A'=> -1,
                    'R'=> 5,
                and so on with all rows

##</code><code>##

my @letters=qw( A R N D);

 sub printMatrix1 {
    my ($A) = @_;
    foreach my $key (sort keys %$A) {
        print $key."  "x2;
        foreach my $key2 (sort keys %{$A->{$key} } )  {
            printf( "%.4f  " , $A->{$key}->{$key2} );
        }
        print "\n"x2;
    }
}