#!/usr/bin/perl
#
#   coords_2_dist_array.pl <FName>
#
#   Given  a list of coordinates in file <FName>, compute the array of point-to-point
#   distances.  If FName isn't given, use DATA
#
use strict;
use warnings;
use autodie;

my $IFH;
my $FName = shift;
if (defined $FName) {
    open $IFH, '<', $FName;
}
else {
    $IFH = \*DATA;
}

my @PTs;
while (<$IFH>) {
    my @coords = split /\s+/,$_;
    push @PTs, [ @coords ] if @coords;
}

for my $i (0 .. $#PTs) {
    my @vals=();
    for my $j (0 .. $#PTs) {
        push @vals, sprintf "%.2f", dist($PTs[$i], $PTs[$j]);
    }
    print join("\t", @vals), "\n";
}

sub dist {
    my ($r1, $r2) = @_;
#    print ref($r1), " ", ref($r2),": ",join(",",@$r1), "; ", join(",",@$r2), "\n";
    die "MISMATCH! $#$r1, $#$r2\n" unless $#$r1 == $#$r2;
    my $sum = 0;
    for my $i (0 .. $#$r1) {
        $sum += ($$r1[$i]-$$r2[$i])**2;
    }
    return sqrt($sum);
}

__DATA__
0 0
300 -100
550 550
800 -200
1100 200
1250 0