{package PDL::3Space;
use PDL;
sub new { my ($class, $parent) = @_;
  my $self = bless {basis_local=>identity(3), origin_local=>zeroes(3)}, $class;
  if (defined $parent) {
    $self->{parent} = $parent;
    $self->{basis} = $self->{basis_local}->flowing x $parent->{basis}->flowing;
    $self->{origin} = ($self->{origin_local}->flowing x $self->{basis}->flowing)->flowing + $parent->{origin}->flowing;
  } else {
    $self->{basis} = $self->{basis_local};
    $self->{origin} = $self->{origin_local}->flowing x $self->{basis}->flowing;
  }
  $self;
}
use overload '""' => sub {$_[0]{basis}->glue(1,$_[0]{origin}).''};
sub basis_update { $_[0]{basis_local} .= $_[1] x $_[0]{basis_local} }
sub origin_move { $_[0]{origin_local} += $_[1] }
sub local { my $local = PDL::3Space->new; $local->{$_} .= $_[0]{$_} for qw(basis_local origin_local); $local}
}