I think you are looking for the maximum of each column?
Perl operates easiest on rows. So one way to do this is to transpose the 2-D array, i.e. make the columns become rows. Here is how to do that...

Update: updated code to do what I think op is asking for..used wind's row code with List::Util::reduce() for a transposed "column".

#!/usr/bin/perl -w
use strict;
use List::Util qw(reduce max);

my @array1=(1,2,3,4,8);
my @array2=(1,4,2,4,5);
my @array3=(1,6,1,7,5);

my @AoA = (\@array1,\@array2,\@array3);
my @transposed;

print "Original array:\n";
printAoA(\@AoA);

## tranpose array to make it easy to do column operations
##   i.e. columns become rows

foreach my $rowref (@AoA)
{
   my $i=0;
   foreach my $num (@$rowref)
   {
      push @{$transposed[$i++]}, $num;
   }
}

##  Now @transposed is an array of references to what used to be
##    columns.

print "\nMaximum of each column...\n".
         "coordinates based on row 0..n, col 0..n\n";
my $col=0;
foreach my $colref (@transposed) 
{
    ## you could have a loop: foreach my $num (@$colref) {} here
    ## below is wind's use of reduce to get the column position of
    ## the first maximum, perhaps you have something different in
    ## mind?
    
    my $max_pos = reduce {$colref->[$b] > $colref->[$a] ? $b : $a} (0.
+.@$colref-1);
    print "Max of column index $col is $colref->[$max_pos] at array in
+dex $max_pos\n";
    $col++;
}

print "\nTransposed array:\n";
printAoA(\@transposed);


sub printAoA
{
   my $refAoA = shift;
   foreach my $rowref (@$refAoA)
   {
     print join(",",@$rowref),"\n";  
   }
}
__END__
Original array:
1,2,3,4,8
1,4,2,4,5
1,6,1,7,5

Maximum of each column...
coordinates based on row 0..n, col 0..n
Max of column index 0 is 1 at array index 0
Max of column index 1 is 6 at array index 2
Max of column index 2 is 3 at array index 0
Max of column index 3 is 7 at array index 2
Max of column index 4 is 8 at array index 0

Transposed array:
1,1,1
2,4,6
3,2,1
4,4,7
8,5,5
[download]

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