CacheCalculation

#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';
use Math::Trig;
my $file = 'datatest.dat';
open my $in, '<', $file or die "File Not Found\n";
my @aa = ();
my @bb = ();
my @cc = ();
my @dd = ();
my $i = 0;
while(<$in>){
  my @data = split;
  my $ra = deg2rad $data[0]; #radに変換
  my $dec = deg2rad $data[1];
  $aa[$i] = cos $dec;
  $bb[$i] = sin $ra;
  $cc[$i] = cos $ra;
  $dd[$i] = sin $dec;
  $i++;
}
close($in);
my $size = scalar @aa;
for ($i = 0; $i < $size; $i++) {
  for (my $j = $i + 1; $j < $size; $j++) {
    my $theta = rad2deg(
      sqrt(
        ($aa[$i] * $bb[$i] - $aa[$j] * $bb[$j]) ** 2 +
        ($aa[$i] * $cc[$i] - $aa[$j] * $cc[$j]) ** 2 +
        ($dd[$i] - $dd[$j]) ** 2
      )
    );
    say $theta;
  }
}