use XML::Writer;
my $writer = XML::Writer->new( NEWLINES=>0, DATA_MODE=>1, DATA_INDENT=>2, );
$writer->startTag("dataset");
for(my $i=0; $i< @ordered_values;$i++)
{
      my $row = $ordered_values[ $i ];
      $writer->startTag("row", "num" => $i);
      for(my$j=0; $j < @$row; $j++)
      {
              $writer->startTag("cdr", "name" => $names[$j]);
              $writer->characters( $row->[ $j ] );
              $writer->endTag();
      }
      $writer->endTag();
}
$writer->endTag();
$writer->end();