ObjStore::Lib::PDL - Persistent PDL-compatible matrices

    use PDL::Lite;
    use ObjStore::Lib::PDL;

    begin 'update', sub {
      my $pdl = ObjStore::Lib::PDL->new($near,
			  { Datatype => PDL::float(), Dims => [3,3] });

      $pdl->slice(":,4")->clump(2) *= 2;  #or whatever
    };
    die if $@;

The main thing of interest is that dimensions are arranged in memory such that the last dimension is the most packed. For example, in a PDL of dimensions [3,3,3] the following locations are sequential in memory:

  [2,1,0]
  [2,1,1]
  [2,1,2]

Whereas the follow three elements are separated by relatively large gaps:

  [0,2,1]
  [1,2,1]
  [2,2,1]

Be aware that this memory layout convention is dependent on the implementation of PDL. However, it is very unlikely to change.