my @pos_array;
my @neg_array;

while ( my $row = <IN> ) {
    if ( /(-\d[.\d]+)/ ) {
        push @neg_array, $1;
    }
    elsif ( /(\d[.\d]+)/ ) {
        push @pos_array $1;
    }
}
# now do stuff with those two arrays...

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

while ( my $row = <DATA>) {
    print $row;
}

__DATA__
10.00
10.00
-30.00