The syntax error is your friend, if it tells you that ]; is bad, then it probably is. If not, then something near it is.

If you were to indent your code in a more clear fashion your code might look like this:

Instantly you'd see that maybe a closing bracket was missing off the my $dmat = pdl [ ... ]; command. And that the final curly brace should probably be swapped with the square bracket the syntax error is complaining about.

Update: posted solution here:

#!/usr/bin/perl -w

use PDL;
$matrixfile = $ARGV[0];
open(MATRIX, "$matrixfile") || die "Error: Can't open $matrixfile file
+ for reading: $!\n";

@matrix = map({chomp; [split(/\s+/, $_)]} <MATRIX>);

for my $ctl (
 [ qw ( 0 1 2 3 ) ],
 [ qw ( 4 1 2 3 ) ],
 [ qw ( 0 4 2 3 ) ],
 [ qw ( 0 1 4 3 ) ],
 [ qw ( 0 1 2 4 ) ],
) {
    for my $data (@matrix) {
        for my $offset (@$ctl) {
            print $data->[$offset], ' ';
        }
        print "\n";
    }
    print "\n";
}
[download]

I don't know much about PDL, but your problem doesn't seem that difficult. You have a file with 4 rows and 5 columns, and you want to compute the determinant of 4x4 matrices obtained by picking, and possibly reordering, 4 out of the 5 columns. Though it's not rocket science to move around columns, it is simpler to move around rows, and since the determinant is not affected by taking the transpose, I'd work with the transpose. I.e. I'd compute the determinants of

pdl [
      [4, 2, 6, 8],
      [2, 5, 3, 4],
      [9, 5, 5, 6],
      [7, 4, 3, 6],
    ],

pdl [
      [21, 11.5, 15.5, 22],
      [2, 5, 3, 4],
      [9, 5, 5, 6],
      [7, 4, 3, 6],
    ],
[download]

my @rows;
my $j = 0;
{
  local @ARGV = $ARGV[ 0 ];
  while ( <> ) {
    my $i = 0;
    $rows[ $i++ ][ $j ] = $_ for split;
    $j++;
  }
}

my $dmat  = pdl [ @rows[ 0, 1, 2, 3 ] ];
my $damat = pdl [ @rows[ 4, 1, 2, 3 ] ]; 
my $dbmat = pdl [ @rows[ 0, 4, 2, 3 ] ];
my $dcmat = pdl [ @rows[ 0, 1, 4, 3 ] ];
my $ddmat = pdl [ @rows[ 0, 1, 3, 4 ] ];

# proceed to compute the determinants of the $dmat, $damat, etc.
[download]

my @rows = grep @$_, map [ split " " ], <>;
my @col = map pop @$_, @rows;

my $dmat = pdl(\@rows);

my @mat = map {
    my $i = $_; pdl([ map {
        my $row = $_;
        [ map { $i==$_ ? $col[$i] : $row->[$_] } 0 .. $#$row ] } @rows
      ])
  } 0 .. $#{$rows[0]};
[download]

This will create the matrix that you want. This is tested. Hope this helps;

#!/usr/bin/perl -w

open(MATRIX, "matrixfile.dat") || die "Error: Can't open matrixfile fi
+le for reading: $!\n";


$i=0;
while ($spool = <MATRIX>) {
    chomp($spool);
    @arr = split(/ /,$spool);
    for ($x=0;$x<= $#arr;$x++) { $matrix[$i][$x] = $arr[$x];}
    $i++;
} # end while

$x=$x-1;
for ($j=0;$j<$i;$j++) {
    for ($r=0;$r<4;$r++)
    {
        print "[ ";
        $cntr=0;$c=$j;
        for($cntr=0;$cntr<4;$cntr++) 
        {
            if($c gt  $x) {
                $c=0;
            }
            print " $matrix[$r][$c]  " ;
            
            $c++;
        }
        print " ] \n";
    }
    print "\n";
}
[download]

Oh .. i use emacs by the way, not notepad ;)

Have you typed M-x perl-mode, selected all your text (perhaps using cua-mode) and typed in M-x indent-region?