sub PDL::mapfraw {
        my $class = shift;
	my($name,$opts) = @_;
	my $hdr;
	if($opts->{Dims}) {
		my $datatype = $opts->{Datatype};
		if(!defined $datatype) {$datatype = $PDL_D;}
		$hdr->{Type} = $datatype;
		$hdr->{Dims} = $opts->{Dims};
		$hdr->{NDims} = scalar(@{$opts->{Dims}});
	} else {
		$hdr = _read_frawhdr($name);
	}
	$s = PDL::Core::howbig($hdr->{Type});
	for(@{$hdr->{Dims}}) {
		$s *= $_;
	}
	my $pdl = $class->zeroes(new PDL::Type($hdr->{Type}));
#	$pdl->dump();
	$pdl->setdims($hdr->{Dims});
#	$pdl->dump();
	$pdl->set_data_by_mmap($name,$s,1,($opts->{ReadOnly}?0:1),
		($opts->{Creat}?1:0),
		(0644),
		($opts->{Creat} || $opts->{Trunc} ? 1:0));
#	$pdl->dump();
	if($opts->{Creat}) {
		_writefrawhdr($pdl,$name);
	}
	return $pdl;
}