my %mythreads;
my $work_package = int($elements / $number_threads + 0.5);
my @ReturnData :shared;
my $start = 0;
my $stop = $start + $work_package * $files - 1;
$stop = $elements * $files - 1 if ($stop >= $elements * $files);

for (my $i = 0; $i < $number_threads; $i++) {
	$mythreads{$i} = threads->create(\&do_work);
	$start = $stop + 1;
	$stop += $work_package * $files;
	$stop = $elements * $files - 1 if ($stop >= $elements * $files);
}
# collect data
foreach (sort(keys(%mythreads))) {
	$mythreads{$_}->join();
}

##</code><code>##

sub do_work {
	my @working_block = @input_data[$start .. $stop];
	my @partial_output_data;
	$, = undef;
	$\ = undef;

	my $output_line = 0;
	for (my $i = 0; $i < @working_block; $i += $files) {
		# calculates the stddev of each slice and outputs the formatted resuls
		if (max(@working_block[$i .. $i + $files - 1]) == 0) {
			$partial_output_data[$output_line] = '0.00000E+00';
		} else {
			$partial_output_data[$output_line] = 
				sprintf('%.5E', stddev(@working_block[$i .. $i + $files - 1]) / 
				mean(@working_block[$i .. $i + $files - 1]));
		}
		$output_line++;
	}
	@ReturnData[$start / $files .. $stop / $files] = @partial_output_data;
	return;
}