in reply to Create a table from a matrix

Perhaps a bit more messy than necessary, but:
use strict; use warnings; my ($c, %k, %vals, %cols, @cols, @table, $row); chomp($_ = <DATA>); s/\s+//g; $c = 0; $k{$_} = $c++ for split /\|/, $_; while (<DATA>) { s/\s+//g; @_ = split /\|/, $_; $vals{@_[$k{'v_id'}]}{@_[$k{'p_id'}]} = @_[$k{'s_id'}]; $cols{@_[$k{'p_id'}]} = (); } @cols = sort { $a <=> $b } keys %cols; push @table, ['', map { 'p_'.$_ } @cols]; for $row (sort { $a <=> $b } keys %vals) { push @table, ['v_'.$row, map { $vals{$row}{$_} ? 's_'.$vals{$row}{ +$_} : '' } @cols]; } table(\@table); sub table { my ($arr, $i, @lengths, $length, $format) = $_[0]; for (@$arr) { for $i (0..$#$_) { $lengths[$i] = length($_->[$i]) if !$lengths[$i] || $lengt +hs[$i] < length($_->[$i]); } } $length = 0; $length += $_ for @lengths; $length += 3 * $#lengths + 2; $format = join ' | ', map { '%-'.$_.'s' } @lengths; for ($i = 0; $i < $#$arr; $i++) { print ' ', sprintf($format, @{$arr->[$i]}), "\n", '-' x $length, "\n"; } print ' ', sprintf($format, @{$arr->[-1]}), "\n"; } __DATA__ p_id | v_id | s_id 1 | 1 | 1 2 | 1 | 2 3 | 1 | 3 4 | 1 | 4 1 | 2 | 5 2 | 2 | 6 3 | 2 | 7 4 | 2 | 8 2 | 3 | 9 4 | 3 | 10 1 | 4 | 11 2 | 4 | 12 4 | 4 | 13 3 | 5 | 14