$pi_sum = 0; $L_sum = 0; $differences_sum = 0; $coverage_sum = 0; for my $PAR1 (@PAR1) { my ($pi, $L, $differences, $coverage) = split(/\t/, $PAR1); $pi_sum = $pi_sum + $pi; $L_sum = $L_sum + $L; $differences_sum = $differences_sum + $differences; $coverage_sum = $coverage_sum + $coverage; my $PAR1_diversity = (($pi_sum/$L_sum)/($differences_sum/$coverage_sum)); }