This class is designed to keep PIF value declaration information and is a child of the object reference class. It is used by GRS to represent the type and dimension of, e.g., a PIF point list, and also holds information about the units of a PIF point list or attribute. Unit conversion factors are also present in this class, but these are only of concern if the internally stored units (i.e. the desired ones upon reading the PIF object) differ from the ones hold on the PIF binary file. The values per data set contained in a PIF value list are also kept internally and computed out of the tensor rank of the value type and the dimensions per tensor rank. This information is used for consistency checks upon writing a PIF object containing a value list, and the write method would complain if, e.g., writing a point list declaring two-dimensional geometric points, but containing an odd number of real values in the value list would be attempted.
The generic point list class is an alias to this class, since its members represent the ``smallest common denominator'' between information contained in a tensor product point list and an unstructured point list, both of which are children of this class. Generic point list manipulation routines which are able to deal both with tensor product and unstructured point lists are therefore defined on this class. For example, the generic point list iteration method is defined on this class, and is used in the ptbInterpolateAttribute() toolbox function to iterate through all points of the new grid an attribute is to be interpolated on, no matter whether the new grid is an orthoProduct grid or an unstructured grid.