The Vset module provides interfaces to two basic HDF building blocks. Vgroups are generic grouping elements allowing a user to associate related objects within an HDF file. As Vgroups can contain other Vgroups, it is possible to build a hierarchical file. Vdatas are generic list objects. Data is organized into "fields" within each Vdata. Each field is identified by a unique "field name". The type of each field may be any of the basic number types that HDF supports. Fields of different types may exist within the same Vdata.
By combining Vdatas in Vgroups, it is possible to represent higher level data constructs: mesh data, multi-variate datasets, sparse matrices, finite-element data, spreadsheets, splines, non-Cartesian coordinate data, etc.
User-defined attributes are available with both Vdatas and Vgroups.