Schematic diagram of the data structure for the composite tree.  In addition to the fundamental TreeModel data the composite tree possesses three mapping tables.  First the forward map, which links each name usage node to a composite node. Second the reverse map, which links the composite node to each name usage node in the hierarchies under comparison.  It can link a single composite node to multiple name usage nodes.  Third the parental name, which links pair of the name literal and its parental name literal of a name usage node to the composite node. It providers a working cache of candidate composite nodes to which the name usage node may map to. If the parental name table contains a composite node that matches a name literal and parental name literal of the name usage node in the hierarchy being processed, the composite node is a good candidate for a mapping.  Examples of some composite nodes in Fig. 1 are shown in the insertion.  There are two entries for composite node D, one is indexed by literals D and B while the other by D and C.  The D-B indexed entry is created for node D in hierarchy h1, while D-C indexed entry is created for node D in hierarchy h2.  Note that the composite tree does not retain the direct parent-child relationship between B and D after insertion of composite node C.  The parental name table has this information even after insertion of composite node C to provide a quick look up table to find composite node D as a candidate for hierarchy node with D and B literal pair, otherwise it is necessary to scan the parental path against hierarchies already incorporated.  The parental name table has two entries for composite nodes S because there are two composite nodes, distinguished by suffixes.  The parental name table also provides a distinction between these two composite nodes.  The three tables are implemented by Java HashMaps.

 
  Part of: Ytow N (2016) Taxonaut: an application software for comparative display of multiple taxonomies with a use case of GBIF Species API. Biodiversity Data Journal 4: e9787. https://doi.org/10.3897/BDJ.4.e9787