#! perl -slw
use strict;
use Data::Dump qw[ pp ];

## Input to separate arrays
my( @xs, @ys );
( $xs[ @xs ], $ys[ @ys ] ) = split while <DATA>;

## cross xs with ys and get pop count of pairings
my %freq;
for my $x ( @xs ) {
    ++$freq{ sprintf "%.2f %.2f", $x, $_ } for @ys;
}
#pp \%freq;

## most plotters require input as vectors, so split them out
my( @rx, @ry, @rz );
( $rx[ @rx ], $ry[ @ry ], $rz[ @rz ] ) = ( split(), $freq{ $_ } ) for keys %freq;

## print them as line vectors
print "@rx";
print "@ry";
print "@rz";

__DATA__
1 2
3 4
5 6
7 8
9 0

##</code><code>##

C:\test>1163636
9.00 3.00 9.00 5.00 7.00 9.00 1.00 7.00 3.00 1.00 1.00 9.00 3.00 3.00 5.00 9.00 3.00 1.00 5.00 7.00 7.00 5.00 7.00 1.00 5.00
6.00 8.00 0.00 8.00 2.00 8.00 2.00 6.00 2.00 8.00 4.00 2.00 4.00 6.00 0.00 4.00 0.00 6.00 4.00 8.00 4.00 2.00 0.00 0.00 6.00
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1