horizontal absolute values of every line - perl

Question

I am trying to calculate the absolute values of line 2 - values of line 1
and then the horizontal absolute values of every line in my input file. Here's a part of that input.
43 402 51 360
63 60 69 63
65 53 89 55
103 138 135 135
109 36 123 38
To be more precise about what im trying to do I made the following example
initial data
0 2 0 0
0 1 1 1
next stage (absolute value after subscription the second line minus the first line)
2 2 0
1 0 0
final stage (horizontal application of abs values until one column remained)
0
1
The below code was a failed attempt to obtain the final stage of the single column. My problem here is that I don't know how to obtain the final (desired) stage by using subroutine, as I believe that it is a better way to solving my problem. Of course, every idea or better approach is welcome.
#!/usr/bin/perl
use feature qw(say);
use strict;
use warnings;
use Data::Dumper;
my #rows = 'table_only_numbers';
open(my $fh, '<:encoding(UTF-8)', $rows)
sub ori {
for ($num_cols=#{ $rows[$r-1]}; $num_cols=1; $num_cols-- ){
my #diff_diffs = map { abs($diffs[$_-1] - $diffs[$_]) } 1..$num_cols-1;
#final=#diff_diffs;
say join ' ',#final;
return (final) }
my $num_cols = #{ $rows[0] };
for my $r (1..$#rows) {
die "Bad format!" if #{ $rows[$r] } != $num_cols;
my #diffs = map { abs($rows[$r-1][$_] - $rows[$r][$_]) } 0..$num_cols-1;
while ($num_cols>1)
{
$final_output = ori(#{ $rows[0] })
say "final_output";
}
}
close $fh;

Answer 1

Finally, I figure it by myself without subroutines!!! Im posting it in case someone face the same issue in the future.I know that it is an easiest way to do it but as I am newbie in Perl it is the easiest way for me.
So I used:
for the first abs of the line 2 minus the line 1
my #data = map { abs($current[$_]-$previous[$_]) } 0..$#current;
push #final, \#data;
To obtain the absolute value of row 2 minus the row 1
And after I used 3 times as I had 3 columns left (in my case) the following coding line and each time I Substituted the #xxx with a new variable. and I have desired output of I column.
foreach my $row (#XXX) {
my #data = map { abs(#{$row}[$_]-#{$row}[$_+1]) } 0..$#{$row}-1;
say join ' ', #data;
push #XXX, \#data;}