NAME

       PDL::IO::HDF5::Group - PDL::IO::HDF5 Helper Object representing HDF5 groups.

DESCRIPTION

       This is a helper-object used by PDL::IO::HDF5 to interface with HDF5 format's group
       objects.  Information on the HDF5 Format can be found at the HDF Group's web site at
       http://www.hdfgroup.org .

SYNOPSIS

       See PDL::IO::HDF5

MEMBER DATA

       ID
        ID number given to the group by the HDF5 library

       name
        Name of the group. (Absolute to the root group '/'. e.g. /maingroup/subgroup)

       parent
        Ref to parent object (file or group) that owns this group.

       fileObj
        Ref to the PDL::IO::HDF5 object that owns this object.

METHODS

       ####---------------------------------------------------------

   new
       PDL::IO::HDF5::Group Constructor - creates new object

       Usage:

       This object will usually be created using the calling format detailed in the SYNOPSIS. The
       following syntax is used by the PDL::IO::HDF5 object to build the object.

          $a = new PDL::IO::HDF5:Group( name => $name, parent => $parent,
                                     fileObj => $fileObj );
               Args:
               $name                           Name of the group (relative to the parent)
               $parent                         Parent Object that owns this group
               $fileObj                        PDL::HDF (Top Level) object that owns this group.

   DESTROY
       PDL::IO::HDF5 Destructor - Closes the HDF5::Group Object.

       Usage:

          No Usage. Automatically called

   attrSet
       Set the value of an attribute(s)

       Supports null-terminated strings, integers and floating point scalar and 1D array
       attributes.

       Usage:

          $group->attrSet( 'attr1' => 'attr1Value',
                           'attr2' => 'attr2 value',
                           'attr3' => $pdl,
                           .
                           .
                           .
                          );

       Returns undef on failure, 1 on success.

   attrGet
       Get the value of an attribute(s)

       Supports null-terminated strings, integer and floating point scalar and 1D array
       attributes.

       Usage:

          my @attrs = $group->attrGet( 'attr1', 'attr2');

   attrDel
       Delete attribute(s)

       Usage:

          $group->attrDel( 'attr1',
                           'attr2',
                           .
                           .
                           .
                          );

       Returns undef on failure, 1 on success.

   attrs
       Get a list of all attribute names in a group

       Usage:

          @attrs = $group->attrs;

   dataset
       Open an existing or create a new dataset in a group.

       Usage:

          $dataset = $group->dataset('newdataset');

       Returns undef on failure, 1 on success.

   datasets
       Get a list of all dataset names in a group. (Relative to the current group)

       Usage:

          @datasets = $group->datasets;

   group
       Open an existing or create a new group in an existing group.

       Usage:

          $newgroup = $oldgroup->group("newgroup");

       Returns undef on failure, 1 on success.

   groups
       Get a list of all group names in a group. (Relative to the current group)

       Usage:

          @groupNames = $group->groups;

   _buildAttrIndex
       Internal Recursive Method to build the attribute index hash for the object

       For the purposes of indexing groups by their attributes, the attributes are applied
       hierarchial. i.e. any attributes of the higher level groups are assumed to be apply for
       the lower level groups.

       Usage:

          $group->_buildAttrIndex($index, $currentAttrs);

        Input/Output:

                $index:        Total Index hash ref
                $currentAttrs: Hash refs of the attributes valid
                               for the current group.

   IDget
       Returns the HDF5 library ID for this object

       Usage:

        my $ID = $groupObj->IDget;

   nameGet
       Returns the HDF5 Group Name for this object. (Relative to the root group)

       Usage:

        my $name = $groupObj->nameGet;

   reference
       Creates a reference to a region of a dataset.

       Usage:

         $groupObj->reference($referenceName,$datasetObj,@regionStart,@regionCount);

       Create a reference named $referenceName within the group $groupObj to a subroutine of the
       dataset $datasetObj. The region to be referenced is defined by the @regionStart and
       @regionCount arrays.

   unlink
       Unlink an object from a group.

       Usage:

         $groupObj->unlink($objectName);

       Unlink the named object from the group.