in reply to Re^2: Break an array. I think.
in thread Break an array. I think.

Or a little more simply, 
for my $i (0 .. $#datan/3) {
  print join(' ', @datan[$i*3 .. $i*3 + 2]), "\n";
}

[download]
It looks to me like you introduced @x so that splice wouldn't destroy the original array, but then opted not to use splice after all.
Caution: Contents may have been coded under pressure.

In Section Seekers of Perl Wisdom